Expressions/ru: Difference between revisions

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<span id="Overview"></span>
==Обзор==
==Обзор==


Некоторые свойства объектов могут быть определены с помощью математических выражений. В графическом интерфейсе счетчики или поля ввода свойств которые поддерживают выражения, содержат синий значок [[Image:Bound-expression.svg|24px]]. Щелчок по значку или ввод знака равенства {{KEY|&#61;}} вызывает редактор выражений для этого конкретного свойства.
Некоторые свойства объектов могут быть определены с помощью математических выражений. В графическом интерфейсе счетчики или поля ввода свойств которые поддерживают выражения, содержат синий значок [[Image:Bound-expression.svg|24px]]. Щелчок по значку или ввод знака равенства {{KEY|&#61;}} вызывает редактор выражений для этого конкретного свойства.


<div class="mw-translate-fuzzy">
Выражение FreeCAD - это математическое выражение, следующее за обозначениями стандартных математических операторов и функций, как описано ниже. Кроме того, выражение может ссылаться на другие свойства, а также использовать условные выражения. К числам в выражении может быть добавлена необязательная единица измерения.
Выражение FreeCAD - это математическое выражение, следующее за обозначениями стандартных математических операторов и функций, как описано ниже. Кроме того, выражение может ссылаться на другие свойства, а также использовать условные выражения. К числам в выражении может быть добавлена необязательная единица измерения.
</div>


<div class="mw-translate-fuzzy">
В числах, для отделение целых цифр от десятичных, можно использовать запятую {{incode|,}} или десятичную точку {{incode|.}}.
В числах, для отделение целых цифр от десятичных, можно использовать запятую {{incode|,}} или десятичную точку {{incode|.}}.
Когда используется такой разделитель (точка или запятая), за ним ''должна'' следовать хотя бы одна цифра.
Когда используется такой разделитель (точка или запятая), за ним ''должна'' следовать хотя бы одна цифра.
Таким образом, выражения '''1.+2.''' и '''1,+2,''' недопустимы, но '''1.0 + 2.0''' и '''1,0 + 2,0''' действительны.
Таким образом, выражения '''1.+2.''' и '''1,+2,''' недопустимы, но '''1.0 + 2.0''' и '''1,0 + 2,0''' действительны.
</div>


<div class="mw-translate-fuzzy">
Операторы и функции зависят от единиц измерения и требуют допустимых комбинаций единиц, если таковые имеются. Например, {{incode|2mm + 4mm}} является допустимым выражением, а {{incode|2mm + 4}} - нет (причина в том, что выражение типа {{incode|1in + 4}} люди обычно интерпретируют как {{incode|1 дюйм + 4 дюйма}}, но все единицы внутренне преобразуются в систему СИ, и система не может это угадать). В настоящее время распознаются такие [[#Единицы_измерения|единицы]].
Операторы и функции зависят от единиц измерения и требуют допустимых комбинаций единиц, если таковые имеются. Например, {{incode|2mm + 4mm}} является допустимым выражением, а {{incode|2mm + 4}} - нет (причина в том, что выражение типа {{incode|1in + 4}} люди обычно интерпретируют как {{incode|1 дюйм + 4 дюйма}}, но все единицы внутренне преобразуются в систему СИ, и система не может это угадать). В настоящее время распознаются такие [[#Единицы_измерения|единицы]].
</div>


Some unit related errors can seem unintuitive, with expressions either being rejected or producing results that do not match the units of the property being set. Here are some examples:
Вы можете использовать [[#Поддерживаемые_константы|константные значения]] и [[#Поддерживаемые_функции|функции]].


{{incode|1/2mm}} is not interpreted as half a millimeter but as {{incode|1/(2mm)}}, resulting in: {{incode|0.5 mm^-1}}.

{{incode|sqrt(2)mm}} is not valid because the function call is not a number. This has to be entered as {{incode|sqrt(2) * 1mm}}.

<span id="Function_arguments"></span>
===Аргументы функции ===
===Аргументы функции ===


Multiple arguments to a function may be separated by either a semicolon {{incode|;}} or a comma <em>followed by a space</em> {{incode|, }}. In the latter case, the comma is converted to a semicolon after entry. When a semicolon is used, no trailing space is necessary.
Multiple arguments to a function may be separated by either a semicolon {{incode|;}} or a comma <em>followed by a space</em> {{incode|, }}. In the latter case, the comma is converted to a semicolon after entry. When a semicolon is used, no trailing space is necessary.


Arguments may include references to cells in a spreadsheet. A cell reference consists of the cell's uppercase row letter followed by its column number, for example {{incode|A1}}. A cell may also be referenced by using the cell's alias instead, for example {{incode|Spreadsheet.MyPartWidth}}.
Arguments may include references to cells in a spreadsheet. A cell reference consists of the cell's uppercase row letter followed by its column number, for example {{incode|A1}}. A cell may also be referenced by using the cell's alias instead, for example {{incode|Spreadsheet.MyPartWidth}}.

===Referencing objects===


<span id="Referencing_objects"></span>
You can reference an object by its {{PropertyData|Name}} or by its {{PropertyData|Label}}. In the case of a {{PropertyData|Label}}, it must be enclosed in double {{incode|<<}} and {{incode|>>}} symbols, such as {{incode|<<Label>>}}.
===Ссылка на объект в выражении===


You can reference any property of an object. For example, to reference a Cylinder's height, you may use {{incode|Cylinder.Height}} or {{incode|<<Long_name_of_cylinder>>.Height}}. To reference the object itself use the {{incode|_self}} pseudo property. For example, you may use {{incode|Cylinder._self}} or {{incode|<<Label_of_cylinder>>._self}}.
As already shown above, you can reference an object by its {{PropertyData|Name}}. But you can also use its {{PropertyData|Label}}. In the case of a {{PropertyData|Label}}, it must be enclosed in double {{incode|<<}} and {{incode|>>}} symbols, such as {{incode|<<Label>>}}.


To reference list objects, use {{incode|<<object_label>>.list[list_index]}} or {{incode|object_name.list[list_index]}}. If you want for example to reference a constraint in a sketch, use {{incode|<<MySketch>>.Constraints[16]}}. If you are in the same sketch you may omit its name and just use {{incode|Constraints[16]}}.<br/>
You can reference any property of an object. For example, to reference a Cylinder's height, you may use {{incode|Cylinder.Height}} or {{incode|<<Label_of_cylinder>>.Height}}.
'''Note:''' The index starts with 0, therefore constraint 17 has the index 16.


For more information about referencing objects, see [[#Reference_to_CAD_data|Reference to CAD_data]].
For more information about referencing objects, see [[#Reference_to_CAD_data|Reference to CAD data]].
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<span id="Supported_constants"></span>
== Поддерживаемые константы ==
== Поддерживаемые константы ==


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|}
|}
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<span id="Supported_operators"></span>
== Поддерживаемые операторы ==
== Поддерживаемые операторы ==


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|}
|}
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<span id="Supported_functions"></span>
== Поддерживаемые функции ==
== Поддерживаемые функции ==


<span id="General_mathematical_functions"></span>
=== Основные математические функции ===
=== Основные математические функции ===


Поддерживаются следующие математические функции:
Поддерживаются следующие математические функции:


<span id="Trigonometric_functions"></span>
==== Функции тригонометрии ====
==== Функции тригонометрии ====


[https://en.wikipedia.org/wiki/Trigonometric_functions Trigonometric functions] use degree as their default unit. For radian measure, add {{incode|rad}} following the <em>first</em> value in an expression. So e.g. {{incode|cos(45)}} is the same as {{incode|cos(pi rad / 4)}}. Expressions in degrees can use either {{incode|deg}} or {{incode|°}}, e.g. {{incode|360deg - atan2(3; 4)}} or {{incode|360&deg; - atan2(3; 4)}}. If an expression is without units and needs to be converted to degrees or radians for compatibility, multiply by {{incode|1&nbsp;deg}}, {{incode|1&nbsp;°}} or {{incode|1&nbsp;rad}} as appropriate, e.g. {{incode|(360 - X) * 1deg}}; {{incode|(360 - X) * 1°}}; {{incode|(0.5 + pi / 2) * 1rad}}.
[https://en.wikipedia.org/wiki/Trigonometric_functions Trigonometric functions] use degree as their default unit. For radians add {{incode|rad}} following the <em>first</em> value in an expression. So e.g. {{incode|cos(45)}} is the same as {{incode|cos(pi rad / 4)}}. Expressions in degrees can use either {{incode|deg}} or {{incode|°}}, e.g. {{incode|360deg - atan2(3; 4)}} or {{incode|360&deg; - atan2(3; 4)}}. If an expression is without units and needs to be converted to degrees or radians for compatibility, multiply by {{incode|1deg}}, {{incode|1°}} or {{incode|1rad}} as appropriate, e.g. {{incode|(360 - X) * 1deg}}; {{incode|(360 - X) * 1°}}; {{incode|(0.5 + pi / 2) * 1rad}}.


<div class="mw-translate-fuzzy">
{| class="wikitable"
{| class="wikitable"
!style="width: 15%;"|Функция
!style="width: 15%;"|Функция
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| x и y > 0, x >= y
| x и y > 0, x >= y
|}
|}
</div>


<span id="Exponential_and_logarithmic_functions"></span>
==== Экспоненциальные и логарифмические функции ====
==== Экспоненциальные и логарифмические функции ====


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!style="width: 33%;"|Function
!style="width: 33%;"|Function
!style="width: 33%;"|Description
!style="width: 33%;"|Description
!style="width: 33%;"|Value range
!style="width: 33%;"|Input range
|-
|-
| exp(x)
| {{incode|exp(x)}}
| [https://en.wikipedia.org/wiki/Exponential_function#Formal_definition Exponential function]
| [https://en.wikipedia.org/wiki/Exponential_function#Formal_definition Exponential function]
| all
| all
|-
|-
| log(x)
| {{incode|log(x)}}
| [https://en.wikipedia.org/wiki/Natural_logarithm Natural logarithm]
| [https://en.wikipedia.org/wiki/Natural_logarithm Natural logarithm]
| x > 0
| x > 0
|-
|-
| log10(x)
| {{incode|log10(x)}}
| [https://en.wikipedia.org/wiki/Common_logarithm Common logarithm]
| [https://en.wikipedia.org/wiki/Common_logarithm Common logarithm]
| x > 0
| x > 0
|-
|-
| pow(x; y)
| {{incode|pow(x; y)}}
| [https://en.wikipedia.org/wiki/Exponentiation Exponentiation]
| [https://en.wikipedia.org/wiki/Exponentiation Exponentiation]
| all
| all
|-
|-
| sqrt(x)
| {{incode|sqrt(x)}}
| [https://en.wikipedia.org/wiki/Square_root Square root]
| [https://en.wikipedia.org/wiki/Square_root Square root]
| x >= 0
| x >= 0
|-
| {{incode|cbrt(x)}} {{Version|0.21}}
| [https://en.wikipedia.org/wiki/Cube_root Cubic root]
| all
|}
|}


<span id="Rounding,_truncation_and_remainder_functions"></span>
==== Функции округления, усечения и вычисления остатка от деления ====
==== Функции округления, усечения и вычисления остатка от деления ====


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!style="width: 20%;"|Function
!style="width: 20%;"|Function
!style="width: 55%;"|Description
!style="width: 55%;"|Description
!style="width: 25%;"|Value range
!style="width: 25%;"|Input range
|-
|-
| abs(x)
| {{incode|abs(x)}}
| [https://en.wikipedia.org/wiki/Absolute_value Absolute value]
| [https://en.wikipedia.org/wiki/Absolute_value Absolute value]
| all
| all
|-
|-
| ceil(x)
| {{incode|ceil(x)}}
| [https://en.wikipedia.org/wiki/Floor_and_ceiling_functions Ceiling function], smallest integer value greater than or equal to x
| [https://en.wikipedia.org/wiki/Floor_and_ceiling_functions Ceiling function], smallest integer value greater than or equal to x
| all
| all
|-
|-
| floor(x)
| {{incode|floor(x)}}
| [https://en.wikipedia.org/wiki/Floor_and_ceiling_functions Floor function], largest integer value less than or equal to x
| [https://en.wikipedia.org/wiki/Floor_and_ceiling_functions Floor function], largest integer value less than or equal to x
| all
| all
|-
|-
| mod(x; y)
| {{incode|mod(x; y)}}
| [https://en.wikipedia.org/wiki/Remainder Remainder] after dividing ''x'' by ''y''
| [https://en.wikipedia.org/wiki/Remainder Remainder] after dividing ''x'' by ''y'', sign of result is that of the dividend.
| all, except y = 0
| all, except y = 0
|-
|-
| round(x)
| {{incode|round(x)}}
| [https://en.wikipedia.org/wiki/Rounding Rounding] to the nearest integer
| [https://en.wikipedia.org/wiki/Rounding Rounding] to the nearest integer
| all
| all
|-
|-
| trunc(x)
| {{incode|trunc(x)}}
| [https://en.wikipedia.org/wiki/Truncation Truncation] to the nearest integer in the direction of zero
| [https://en.wikipedia.org/wiki/Truncation Truncation] to the nearest integer in the direction of zero
| all
| all
|}
|}
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<span id="Statistical_/_aggregate_functions"></span>
=== Statistical / aggregate functions ===
=== Функции агрегирования и статистики ===


[https://en.wikipedia.org/wiki/Aggregate_function Aggregate functions] take one or more arguments.<br>
[https://en.wikipedia.org/wiki/Aggregate_function Aggregate functions] take one or more arguments.<br>


Individual arguments to aggregate functions may consist of ranges of cells. A range of cells is expressed as two cell references separated by a colon {{Incode|:}}, for example {{Incode|average(B1:B8)}} or {{Incode|sum(A1:A4; B1:B4)}}.
Individual arguments to aggregate functions may consist of ranges of cells. A range of cells is expressed as two cell references separated by a colon {{Incode|:}}, for example {{Incode|average(B1:B8)}} or {{Incode|sum(A1:A4; B1:B4)}}.
The cell references may also use cell aliases, for example {{Incode|average(StartTemp:EndTemp)}}.
The cell references may also use cell aliases, for example {{Incode|average(StartTemp:EndTemp)}}.


Поддерживаются следующие функции агрегирования:
The following aggregate functions are supported:


{| class="wikitable"
{| class="wikitable"
!style="width: 20%;"|Function
!style="width: 20%;"|Function
!style="width: 55%;"|Description
!style="width: 55%;"|Description
!style="width: 25%;"|Value range
!style="width: 25%;"|Input range
|-
|-
| average(a; b; c; ...)
| {{incode|average(a; b; c; ...)}}
| [https://en.wikipedia.org/wiki/Arithmetic_mean Average] value of the arguments; same as sum(a; b; c; ...) / count(a; b; c; ...)
| [https://en.wikipedia.org/wiki/Arithmetic_mean Average] value of the arguments, same as sum(a; b; c; ...) / count(a; b; c; ...)
| all
| all
|-
|-
| count(a; b; c; ...)
| {{incode|count(a; b; c; ...)}}
| [https://en.wikipedia.org/wiki/Counting Count] of the arguments; typically used for cell ranges
| [https://en.wikipedia.org/wiki/Counting Count] of the arguments, typically used for cell ranges
| all
| all
|-
|-
| max(a; b; c; ...)
| {{incode|max(a; b; c; ...)}}
| [https://en.wikipedia.org/wiki/Maxima_and_minima Maximum] value of the arguments
| [https://en.wikipedia.org/wiki/Maxima_and_minima Maximum] value of the arguments
| all
| all
|-
|-
| min(a; b; c; ...)
| {{incode|min(a; b; c; ...)}}
| [https://en.wikipedia.org/wiki/Maxima_and_minima Minimum] value of the arguments
| [https://en.wikipedia.org/wiki/Maxima_and_minima Minimum] value of the arguments
| all
| all
|-
|-
| stddev(a; b; c; ...)
| {{incode|stddev(a; b; c; ...)}}
| [https://en.wikipedia.org/wiki/standard_deviation Standard deviation] of the values of the arguments
| [https://en.wikipedia.org/wiki/standard_deviation Standard deviation] of the values of the arguments
| all
| all
|-
|-
| sum(a; b; c; ...)
| {{incode|sum(a; b; c; ...)}}
| [https://en.wikipedia.org/wiki/Summation Sum] of the values of the arguments; typically used for cell ranges
| [https://en.wikipedia.org/wiki/Summation Sum] of the values of the arguments, typically used for cell ranges
| all
| all
|}
|}
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<span id="String_manipulation"></span>
=== Операции со строками ===
=== Операции со строками ===


<span id="String_identification"></span>
==== Идентификация строк ====
==== Идентификация строк ====


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In following example, "TEXT" is recognized as a string : {{incode|<<TEXT>>}}
In following example, "TEXT" is recognized as a string : {{incode|<<TEXT>>}}


<span id="String_concatenation"></span>
==== Объединение строк ====
==== Объединение строк ====


Строки могут быть объединены с помощью символа "+".
Strings can be concatenated using the '+' sign.


Following example {{incode|<<MY>> + <<TEXT>>}} will be concatenated to "MYTEXT".
Например строки {{incode|<<МОЙ>> + <<ТЕКСТ>>}} будут объединены в "МОЙТЕКСТ".


<span id="String_conversion"></span>
==== String conversion ====
==== Преобразование числа в строку ====


Числовые значения могут быть преобразованы в строки с помощью функции {{incode|str}}:
Numerical values can be converted to strings with the {{incode|str}} function:


{{incode|str(Box.Length.Value)}}
{{incode|str(Box.Length.Value)}}


<span id="String_formatting"></span>
==== Форматирование строк ====
==== Форматирование строк ====


Форматирование строк поддерживается с использованием (старого) Python способа в стиле %.
String formatting is supported using the (old) %-style Python way.


All %-specifiers as defined in [https://docs.python.org/3/library/stdtypes.html#printf-style-string-formatting Python documentation].
Сведения о всех %-спецификаторах, можно узнать из [https://docs.python.org/3/library/stdtypes.html#printf-style-string-formatting документации Python].


As an example, supposing you have a default 10mm-side cube named 'Box' (default FreeCAD naming), the following expression {{incode|<<Cube length : %s>> % Box.Length}} will expand to "Cube length : 10.0 mm"
As an example, supposing you have a default 10mm-side cube named 'Box' (default FreeCAD naming), the following expression {{incode|<<Cube length : %s>> % Box.Length}} will expand to "Cube length : 10.0 mm"
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For more than one %-specifier use the following syntax: {{incode|<<Cube length is %s and width is %s>> % tuple(Box.Length; Box.Width)}}. Or use concatenation: {{incode|<<Cube length is %s>> % Box.Length + << and width is %s>> % Box.Width}}. Both will expand to "Cube length is 10.0 mm and width is 10.0 mm".
For more than one %-specifier use the following syntax: {{incode|<<Cube length is %s and width is %s>> % tuple(Box.Length; Box.Width)}}. Or use concatenation: {{incode|<<Cube length is %s>> % Box.Length + << and width is %s>> % Box.Width}}. Both will expand to "Cube length is 10.0 mm and width is 10.0 mm".


A FreeCAD sample file using string formatting is available [https://forum.freecadweb.org/viewtopic.php?f=8&t=58657 in the forum]
Пример файла FreeCAD с применением форматирования строк доступен [https://forum.freecadweb.org/viewtopic.php?f=8&t=58657 на форуме]
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<span id="Object_creation_functions"></span>
<div class="mw-translate-fuzzy">
=== Функция Create ===
=== Функция Create ===
</div>


<div class="mw-translate-fuzzy">
С помощью функции {{incode|create}} в выражениях могут быть созданы следующие объекты :
С помощью функции {{incode|create}} в выражениях могут быть созданы следующие объекты :
* Vector
* Vector
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* Rotation
* Rotation
* Placement
* Placement
</div>


{| class="wikitable"
The {{incode|create}} function passes subsequent arguments to the underlying Python constructor when creating the object.
! Type
! Function
! Description
|-
| {{incode|Tuple}}
| {{incode|tuple(a; b; ...)}}
| Example: {{incode|tuple(2; 1; 2)}}
|-
| {{incode|List}}
| {{incode|list(a; b; ...)}}
| Example: {{incode|list(2; 1; 2)}}
|-
| rowspan="2" | [[Vector API|{{incode|Vector}}]]
| {{incode|vector(x; y; z)}}
| rowspan="2" | Create a vector using three unit-less or {{incode|Length}} unit values.
Example: {{incode|vector(2; 1; 3)}}
|-
| {{incode|create(<<vector>>; x; y; z)}}
|-
| rowspan="2" | [[Matrix API|{{incode|Matrix}}]]
|
matrix(
a<sub>11</sub>; a<sub>12</sub>; a<sub>13</sub>; a<sub>14</sub>;
a<sub>21</sub>; a<sub>22</sub>; a<sub>23</sub>; a<sub>24</sub>;
a<sub>31</sub>; a<sub>32</sub>; a<sub>33</sub>; a<sub>34</sub>;
a<sub>41</sub>; a<sub>42</sub>; a<sub>43</sub>; a<sub>44</sub>
)
| rowspan="2" | Create a 4x4 matrix in [https://en.wikipedia.org/wiki/Row-_and_column-major_order row-major order]:
<math>
\begin{bmatrix}
a_{11} & a_{12} & a_{13} & a_{14} \\
a_{21} & a_{22} & a_{23} & a_{24} \\
a_{31} & a_{32} & a_{33} & a_{34} \\
a_{41} & a_{42} & a_{43} & a_{44} \\
\end{bmatrix}
</math>


A minimum of 1 argument can be supplied such as {{incode|matrix(1)}} which creates an identity matrix.
Various mathematical operations such as multiplication, addition, and subtraction are supported via standard mathematical operators (e.g. {{incode|*}}, {{incode|+}}, {{incode|-}}).


Example: {{incode|matrix(1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16)}}
==== Vector ====
|-
| {{incode|create(<<matrix>>; a<sub>11</sub>; a<sub>12</sub>; ...; a<sub>44</sub>)}}
|-
| rowspan="4" | {{incode|Rotation}}
| {{incode|rotation(axis; angle)}}
| rowspan="4" | Create a {{incode|Rotation}} by specifying its {{incode|axis}} ({{incode|Vector}}) and {{incode|angle}} ({{incode|Angle}} unit or unit-less), or three Euler angles {{incode|α}}, {{incode|β}}, {{incode|γ}}.
Examples:
* {{incode|rotation(vector(0; 1; 0); 45)}}
* {{incode|create(<<rotation>>; 30; 30; 30)}}
|-
| {{incode|rotation(α; β; γ)}}
|-
| {{incode|create(<<rotation>>; axis; angle)}}
|-
| {{incode|create(<<rotation>>; α; β; γ)}}
|-
| rowspan="5" | [[Placement_API|{{incode|Placement}}]]
| {{incode|placement(base; rotation)}}
| rowspan="5" | Create a {{incode|Placement}} with various parameters, including:
* {{incode|base}}: base location ({{incode|Vector}})
* {{incode|center}}: center location ({{incode|Vector}})
* {{incode|rotation}}: {{incode|Rotation}}
* {{incode|axis}}: Rotation axis ({{incode|Vector}})
* {{incode|angle}}: Rotation angle (unit-less or {{incode|Angle}} unit value)
* {{incode|matrix}}: {{incode|Matrix}}


Examples:
When {{incode|create}} is passed {{incode|<<vector>>}} as the 1st argument, the next 3 arguments are the X, Y, and Z coordinates for the {{incode|Vector}} respectively.
* {{incode|placement(vector(2; 1; 3); rotation(vector(0; 0; 1); 45))}}

* {{incode|create(<<placement>>; create(<<vector>>; 2; 1; 2); create(<<rotation>>; create(<<vector>>; 0; 1; 0); 45))}}
Example:
|-
| {{incode|placement(base; rotation; center)}}
|-
| {{incode|placement(base; axis; angle)}}
|-
| {{incode|placement(matrix)}}
|-
| {{incode|create(<<placement>>; ...)}}
|}
{{Top}}
=== Vector functions ===


Functions: {{Version|1.0}}.
{{incode|create(<<vector>>; 2; 1; 2)}}

==== Matrix ====

When {{incode|create}} is passed {{incode|<<matrix>>}} as the 1st argument, the next 16 arguments are the elements for the {{incode|Matrix}} in [https://en.wikipedia.org/wiki/Row-_and_column-major_order row-major order].

Example:

{{incode|create(<<matrix>>; 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16)}}

==== Rotation ====

When {{incode|create}} is passed {{incode|<<rotation>>}} as the 1st argument, there are two ways to create a {{incode|Rotation}}:

1. Specify an axis vector and a rotation angle.

Пример:

{{incode|create(<<rotation>>; create(<<vector>>; 0; 1; 0); 45)}}

2. Specify 3 rotations about the X, Y, and Z axes as Euler angles.

Пример:

{{incode|create(<<rotation>>; 30; 30; 30)}}

==== Placement ====

When {{incode|create}} is passed {{incode|<<placement>>}} as the 1st argument, there are five ways to create a {{incode|Placement}}.

These possible combinations are documented in the below table and are based on the [[Placement_API|Placement API]] page.


{| class="wikitable"
{| class="wikitable"
! Function / Operator
!style="width: 33%;"|Number of arguments
!style="width: 66%;"|Description
! Description
|-
|-
| {{incode|v1 + v2}}
| 2
| Add two vectors.
| {{incode|create(<<placement>>; Placement)}}
|-
|-
| {{incode|v1 - v2}}
| 2
| Subtract two vectors.
| {{incode|create(<<placement>>; Matrix)}}
|-
|-
| {{incode|v * s}}
| 3
| Uniformly scale a vector by {{incode|s}}.
| {{incode|create(<<placement>>; Base; Rotation)}}
|-
|-
| {{incode|vangle(v1; v2)}}
| 4
| Angle between two vectors in degrees.
| {{incode|create(<<placement>>; Base; Rotation; Center)}}
|-
|-
| {{incode|vcross(v1; v2)}}
| 4
| Cross product of two vectors <math>v_1 \times v_2</math>.
| {{incode|create(<<placement>>; Base; Axis; Angle)}}
|-
| {{incode|v1 * v2}}
| rowspan="2" | Dot product of two vectors <math>v_1 \cdot v_2</math>.
|-
| {{incode|vdot(v1; v2)}}
|-
| {{incode|vlinedist(v1; v2; v3)}}
| Distance between vector {{incode|v1}} and a line through {{incode|v2}} in direction {{incode|v3}}.
|-
| {{incode|vlinesegdist(v1; v2; v3)}}
| Distance between vector {{incode|v1}} and the closest point on a line segment from {{incode|v2}} to {{incode|v3}}.
|-
| {{incode|vlineproj(v1; v2; v3)}}
| Project vector {{incode|v1}} on a line through {{incode|v2}} in direction {{incode|v3}}.
|-
| {{incode|vnormalize(v)}}
| Normalize a vector to a unit vector.
|-
| {{incode|vplanedist(v1)}}
| Distance between vector {{incode|v1}} and a plane defined by a point {{incode|v2}} and a normal {{incode|v3}}.
|-
| {{incode|vplaneproj(v1)}}
| Project vector {{incode|v1}} on a plane defined by a point {{incode|v2}} and a normal {{incode|v3}}.
|-
| {{incode|vscale(v; sx; sy; sz)}}
| rowspan="4" | Non-uniformly scale a vector by {{incode|sx}} in the X direction, {{incode|sy}} in the Y direction, and {{incode|sz}} in the Z direction.
|-
| {{incode|vscalex(v; sx)}}
|-
| {{incode|vscaley(v; sy)}}
|-
| {{incode|vscalez(v; sz)}}
|}
|}

The following example shows the syntax for creating a {{incode|Placement}} from a {{incode|Base}} (vector) and a {{incode|Rotation}}:

{{incode|create(<<placement>>; create(<<vector>>; 2; 1; 2); create(<<rotation>>; create(<<vector>>; 0; 1; 0); 45))}}

For readability, you can define vectors and rotations in separate cells, and then reference the cells in your expression.
{{Top}}
{{Top}}
=== Matrix functions ===
=== Matrix functions ===


{{incode|Rotation}} and {{incode|Placement}} can each be represented by a {{incode|Matrix}}. The following functions all take in a {{incode|Matrix}}, {{incode|Rotation}}, or {{incode|Placement}} as their first parameter denoted in the table below by {{incode|m}}. The type of the returned object is the same as the object supplied in the first argument except when using {{incode|mtranslate}} on a {{incode|Rotation}}, in which case a {{incode|Placement}} will be returned.
==== mscale ====


{| class="wikitable"
Scale a {{incode|Matrix}} with a given {{incode|Vector}}.
! Function

! Description
{{incode|mscale(Matrix; Vector)}}
|-

{{incode|mscale(Matrix; x; y; z)}}
| {{incode|minvert(m)}}
| Calculate the [https://en.wikipedia.org/wiki/Invertible_matrix Inverse matrix].

|-
==== minvert ====
| {{incode|mrotate(m; rotation)}}

| rowspan="3" | [https://en.wikipedia.org/wiki/Transformation_matrix#Rotation_2 Rotate] by either:
Invert the given {{incode|Matrix}}, {{incode|Rotation}}, or {{incode|Placement}}.
* a {{incode|Rotation}}

* an axis ({{incode|Vector}}) and an angle ({{incode|Angle}} unit or unit-less)
{{incode|minvert(Matrix)}}
* three Euler angles {{incode|α}}, {{incode|β}}, {{incode|γ}}

|-
{{incode|minvert(Rotation)}}
| {{incode|mrotate(m; axis; angle)}}

|-
{{incode|minvert(Placement)}}
| {{incode|mrotate(m; α; β; γ)}}
{{Top}}
|-
=== Кортежи и списки ===
| {{incode|mrotatex(m; angle)}}

| [https://en.wikipedia.org/wiki/Transformation_matrix#Rotation_2 Rotate] around the X axis.
Вы можете создавать Python объекты: кортежи {{incode|tuple}} или списки {{incode|list}} с помощью соответствующих функций.
|-

{{incode|tuple(2; 1; 2)}}
| {{incode|mrotatey(m; angle)}}
| [https://en.wikipedia.org/wiki/Transformation_matrix#Rotation_2 Rotate] around the Y axis.

|-
{{incode|list(2; 1; 2)}}
| {{incode|mrotatez(m; angle)}}
| [https://en.wikipedia.org/wiki/Transformation_matrix#Rotation_2 Rotate] around the Z axis.
|-
| {{incode|mtranslate(m; vector)}}
| rowspan="2" | [https://en.wikipedia.org/wiki/Translation_(geometry)#Matrix_representation Translate] by a {{incode|vector}} ({{incode|Vector}}) or X, Y, Z values. If a {{incode|Rotation}} is translated, the returned object is a {{incode|Placement}}.
|-
| {{incode|mtranslate(m; x; y; z)}}
|-
| {{incode|mscale(m; vector)}}
| rowspan="2" | [https://en.wikipedia.org/wiki/Scaling_(geometry)#Matrix_representation Scale] by a {{incode|vector}} ({{incode|Vector}}) or X, Y, Z values.
|-
| {{incode|mscale(m; x; y; z)}}
|}
{{Top}}
{{Top}}
<span id="Conditional_expressions"></span>
== Условные выражения ==
== Условные выражения ==


Conditional expressions are of the form {{incode|condition ? resultTrue : resultFalse}}. The condition is defined as an expression that evaluates to either {{incode|0}} (false) or non-zero (true). Note that enclosing the conditional expression in parentheses is currently considered an error.
Conditional expressions are of the form {{incode|condition ? resultTrue : resultFalse}}. The condition is defined as an expression that evaluates to either {{incode|0}} (false) or non-zero (true).


The following [https://en.wikipedia.org/wiki/Relational_operator#Standard_relational_operators relational operators] are defined:
The following [https://en.wikipedia.org/wiki/Relational_operator#Standard_relational_operators relational operators] are defined:
Line 402: Line 518:
|}
|}
{{Top}}
{{Top}}
<span id="Units"></span>
== Единицы измерений ==
== Единицы измерений ==


Line 415: Line 532:
The following units are recognized by the expression parser:
The following units are recognized by the expression parser:


<span id="Amount_of_substance"></span>
=== Количество вещества ===
=== Количество вещества ===


Line 420: Line 538:
!style="width: 33%;"|Unit
!style="width: 33%;"|Unit
!style="width: 66%;"|Description
!style="width: 66%;"|Description
|-
| mmol
| Milli[https://en.wikipedia.org/wiki/Mole_(unit) mole]
|-
|-
| mol
| mol
Line 425: Line 546:
|}
|}


<span id="Angle"></span>
=== Угол ===
=== Угол ===


Line 456: Line 578:
|}
|}


<span id="Current"></span>
=== Ток ===
=== Ток ===


Line 475: Line 598:
|}
|}


=== Энергия/работа ===
=== Electric capacitance ===


{| class="wikitable mw-collapsible mw-collapsed"
{| class="wikitable mw-collapsible mw-collapsed"
!style="width: 33%;"|Unit
!style="width: 33%;"|Unit
!style="width: 66%;"|Description
!style="width: 66%;"|Description
|-
| pF
| Pico[https://en.wikipedia.org/wiki/Farad farad]
|-
| nF
| Nano[https://en.wikipedia.org/wiki/Farad farad]
|-
| uF
| Micro[https://en.wikipedia.org/wiki/Farad farad]; alternative to the unit µF
|-
| µF
| Micro[https://en.wikipedia.org/wiki/Farad farad]; alternative to the unit uF
|-
| mF
| Milli[https://en.wikipedia.org/wiki/Farad farad]
|-
| F
| [https://en.wikipedia.org/wiki/Farad Farad]; 1 F = 1 s^4·A^2/m^2/kg
|}

=== Electric charge ===

<div class="mw-translate-fuzzy">
Электрический заряд:
{| class="wikitable float-right mw-collapsible mw-collapsed"
!style="width: 33%;"|Единица измерения
!style="width: 66%;"|Описание
|-
| C
| [https://ru.wikipedia.org/wiki/%D0%9A%D1%83%D0%BB%D0%BE%D0%BD Кулон]; 1 C = 1 A·s, {{Version/ru|0.19}}
|}
</div>

=== Electric conductivity ===

{| class="wikitable mw-collapsible mw-collapsed"
!style="width: 33%;"|Unit
!style="width: 66%;"|Description
|-
| uS
| Micro[https://en.wikipedia.org/wiki/Siemens_(unit) siemens]; alternative to the unit µS
|-
| µS
| Micro[https://en.wikipedia.org/wiki/Siemens_(unit) siemens]; alternative to the unit uS
|-
| mS
| Milli[https://en.wikipedia.org/wiki/Siemens_(unit) siemens]
|-
| S
| [https://en.wikipedia.org/wiki/Siemens_(unit) Siemens]; 1 S = 1 s^3·A^2/kg/m^2
|-
| kS
| Kilo[https://en.wikipedia.org/wiki/Siemens_(unit) Siemens]
|-
| MS
| Mega[https://en.wikipedia.org/wiki/Siemens_(unit) Siemens]
|}

=== Electric inductance ===

{| class="wikitable mw-collapsible mw-collapsed"
!style="width: 33%;"|Unit
!style="width: 66%;"|Description
|-
| nH
| Nano[https://en.wikipedia.org/wiki/Henry_(unit) henry]
|-
| uH
| Micro[https://en.wikipedia.org/wiki/Henry_(unit) henry]; alternative to the unit µH
|-
| µH
| Micro[https://en.wikipedia.org/wiki/Henry_(unit) henry]; alternative to the unit uH
|-
| mH
| Milli[https://en.wikipedia.org/wiki/Henry_(unit) henry]
|-
| H
| [https://en.wikipedia.org/wiki/Henry_(unit) Henry]; 1 H = 1 kg·m^2/s^2/A^2
|}

=== Electric potential ===

Электрический потенциал:
{| class="wikitable float-right mw-collapsible mw-collapsed"
!style="width: 33%;"|Единица измерения
!style="width: 66%;"|Описание
|-
| mV
| Милли[https://ru.wikipedia.org/wiki/%D0%92%D0%BE%D0%BB%D1%8C%D1%82 вольт]
|-
| V
| [https://ru.wikipedia.org/wiki/%D0%92%D0%BE%D0%BB%D1%8C%D1%82 Вольт]
|-
| kV
| Кило[https://ru.wikipedia.org/wiki/%D0%92%D0%BE%D0%BB%D1%8C%D1%82 вольт]
|}

=== Electric resistance ===

<div class="mw-translate-fuzzy">
Электрическое сопротивление:
{| class="wikitable float-right mw-collapsible mw-collapsed"
!style="width: 33%;"|Единица измерения
!style="width: 66%;"|Описание
|-
| Ohm
| [https://ru.wikipedia.org/wiki/%D0%9E%D0%BC Ом]; 1 Ohm = 1 kg·m^2/s^3/A^2, {{Version/ru|0.19}}
|-
| kOhm
| Кило[https://ru.wikipedia.org/wiki/%D0%9E%D0%BC ом], {{Version/ru|0.19}}
|-
| MOhm
| Мега[https://ru.wikipedia.org/wiki/%D0%9E%D0%BC ом], {{Version/ru|0.19}}
|}
</div>

<span id="Energy/work"></span>
=== Энергия/работа ===

{| class="wikitable float-right mw-collapsible mw-collapsed"
!style="width: 33%;"|Unit
!style="width: 66%;"|Description
|-
| mJ
| Milli[https://en.wikipedia.org/wiki/Joule joule]
|-
|-
| J
| J
| [https://en.wikipedia.org/wiki/Joule Joule]
| [https://en.wikipedia.org/wiki/Joule Joule]
|-
| kJ
| Kilo[https://en.wikipedia.org/wiki/Joule joule]
|-
| eV
| [https://en.wikipedia.org/wiki/Electronvolt Electronvolt]; 1 eV = 1.602176634e-19 J
|-
| keV
| Kilo[https://en.wikipedia.org/wiki/Electronvolt electronvolt]
|-
| MeV
| Mega[https://en.wikipedia.org/wiki/Electronvolt electronvolt]
|-
| kWh
| [https://en.wikipedia.org/wiki/Kilowatt_hour Kilowatt hour]; 1 kWh = 3.6e6 J
|-
|-
| Ws
| Ws
Line 492: Line 755:
| CV
| CV
| [https://en.wikipedia.org/wiki/Joule Coulomb-volt]; alternative to the unit Joule
| [https://en.wikipedia.org/wiki/Joule Coulomb-volt]; alternative to the unit Joule
|-
| cal
| [https://en.wikipedia.org/wiki/Calorie Calorie]; 1 cal = 4.184 J
|-
| kcal
| Kilo[https://en.wikipedia.org/wiki/Calorie calorie]
|}
|}


<span id="Force"></span>
=== Сила ===
=== Сила ===


Line 516: Line 786:
|}
|}


<span id="Length"></span>
=== Длина ===
=== Длина ===


Line 571: Line 842:
|}
|}


<span id="Luminous_intensity"></span>
=== Интенсивность света ===
=== Интенсивность света ===


Line 581: Line 853:
|}
|}


=== Magnetic flux ===

{| class="wikitable mw-collapsible mw-collapsed"
!style="width: 33%;"|Unit
!style="width: 66%;"|Description
|-
| Wb
| [https://en.wikipedia.org/wiki/Weber_(unit) Weber]; 1 Wb = 1 kg*m^2/s^2/A
|}

=== Magnetic flux density ===

{| class="wikitable mw-collapsible mw-collapsed"
!style="width: 33%;"|Unit
!style="width: 66%;"|Description
|-
| G
| [https://en.wikipedia.org/wiki/Gauss_(unit) Gauss]; 1 G = 1 e-4 T
|-
| T
| [https://en.wikipedia.org/wiki/Tesla_(unit) Tesla]; 1 T = 1 kg/s^2/A
|}

<span id="Mass"></span>
=== Масса ===
=== Масса ===


Line 621: Line 917:
|}
|}


<span id="Power"></span>
=== Мощность ===
=== Мощность ===


Line 630: Line 927:
| [https://en.wikipedia.org/wiki/Watt Watt]
| [https://en.wikipedia.org/wiki/Watt Watt]
|-
|-
| VA
| kW
| [https://en.wikipedia.org/wiki/Volt-ampere Volt-ampere]
| Kilo[https://en.wikipedia.org/wiki/Watt watt]
|}
|}


<span id="Pressure"></span>
=== Давление ===
=== Давление ===


Line 671: Line 969:
|}
|}


<span id="Temperature"></span>
=== Температура ===
=== Температура ===


Line 690: Line 989:
|}
|}


<span id="Time"></span>
=== Время ===
=== Время ===


Line 704: Line 1,004:
| h
| h
| [https://en.wikipedia.org/wiki/Hour Hour]
| [https://en.wikipedia.org/wiki/Hour Hour]
|-
| Hz (1/s)
| [https://en.wikipedia.org/wiki/Hertz Hertz]
|-
| kHz
| Kilo[https://en.wikipedia.org/wiki/Hertz hertz],
|-
| MHz
| Mega[https://en.wikipedia.org/wiki/Hertz hertz]
|-
| GHz
| Giga[https://en.wikipedia.org/wiki/Hertz hertz]
|-
| THz
| Tera[https://en.wikipedia.org/wiki/Hertz hertz]
|}
|}


<span id="Volume"></span>
=== Объем ===
=== Объем ===


Line 711: Line 1,027:
!style="width: 33%;"|Unit
!style="width: 33%;"|Unit
!style="width: 66%;"|Description
!style="width: 66%;"|Description
|-
| ml
| Milli[https://en.wikipedia.org/wiki/Litre liter]
|-
|-
| l
| l
| [https://en.wikipedia.org/wiki/Litre Liter]
| [https://en.wikipedia.org/wiki/Litre Liter]
|-
| cft
| Cubic[https://en.wikipedia.org/wiki/Foot_(unit) foot]
|}

=== Special imperial units ===

{| class="wikitable mw-collapsible mw-collapsed"
!style="width: 33%;"|Unit
!style="width: 66%;"|Description
|-
| mph
| [https://en.wikipedia.org/wiki/Miles_per_hour Miles per hour]
|-
| sqft
| [https://en.wikipedia.org/wiki/Square_foot Square foot]
|}
|}


<span id="Unsupported_units"></span>
=== Неподдерживаемые единицы измерения ===
=== Неподдерживаемые единицы измерения ===


Line 777: Line 1,113:
For example, the label {{incode|Sketch\002}} must be referenced as {{incode|<<Sketch\\002>>}}.
For example, the label {{incode|Sketch\002}} must be referenced as {{incode|<<Sketch\\002>>}}.


<span id="Names"></span>
===Названия===
===Названия===


Line 785: Line 1,122:
!style="width: 66%;"|Description
!style="width: 66%;"|Description
|-
|-
| '''+''', '''-''', '''*''', '''/''', '''^''', '''_''', '''<''', '''>''', '''(''', ''')''', '''{''', '''}''', '''[''', ''']''', '''.''', ''',''', '''='''
| '''+''', '''-''', '''*''', '''/''', '''^''', '''_''', '''<''', '''>''', '''(''', ''')''', '''{''', '''}''', '''[''', ''']''', '''.''', ''',''', '''='''
| Characters that are math operators or part of mathematical constructs
| Characters that are math operators or part of mathematical constructs
|-
|-
Line 814: Line 1,151:
== Reference to CAD data ==
== Reference to CAD data ==


It is possible to use data from the model itself in an expression. To reference a property use{{incode|object.property}}. If the property is a compound of fields, the individual fields can be accessed as {{incode|object.property.field}}.
It is possible to use data from the model itself in an expression. To reference a property use {{incode|object_name.property}} or {{incode|<<object_label>>.property}}, labels must be enclosed in {{incode|<<}} and {{incode|>>}}. If you want to use labels they must be unique.


All next examples reference the object by its name, but in all cases the object label can also be used.
The following table shows some examples:

If the property is a compound of fields, the individual fields can be accessed as {{incode|object_name.property.field}}.

To reference list objects use {{incode|object_name.list[list_index]}}. If you want to reference a constraint in a sketch, use {{incode|Sketch.Constraints[16]}}. If you are in the same sketch you may omit its name and just use {{incode|Constraints[16]}}. Note that the index starts with 0, therefore Constraint17 has to be referenced as {{incode|Constraints[16]}}.

To reference the object itself use the {{incode|_self}} pseudo property: {{incode|object_name._self}}.

The following table shows some more examples:
{| class="wikitable"
{| class="wikitable"
!CAD data
!CAD data
Line 822: Line 1,167:
!Result
!Result
|-
|-
|Parametric Length of a Part-Workbench Cube
|Length of a [[Part_Box|Part Box]]
|{{incode|Cube.Length}}
|{{incode|Box.Length}}
|Length with units mm
|Length with units (mm)
|-
|-
|Volume of the Cube
|Volume of the Box
|{{incode|Cube.Shape.Volume}}
|{{incode|Box.Shape.Volume}}
|Volume in mm&sup3; without units
|Volume in mm&sup3; without units
|-
|-
|Type of the Cube-shape
|Shape type of the Box
|{{incode|Cube.Shape.ShapeType}}
|{{incode|Box.Shape.ShapeType}}
|String: Solid
|String: Solid
|-
|-
|Label of the Cube
|Label of the Box
|{{incode|Cube.Label}}
|{{incode|Box.Label}}
|String: Label
|String: Label
|-
|-
|X-coordinate of center of mass of the Cube
|X-coordinate of center of mass of the Box
|{{incode|Cube.Shape.CenterOfMass.x}}
|{{incode|Box.Shape.CenterOfMass.x}}
|X-coordinate in mm without units
|X-coordinate in mm without units
|-
|-
|X-coordinate of the Box placement
|Full Cube object
|{{incode|Cube._self}}
|{{incode|Box.Placement.Base.x}}
|X-coordinate with units (mm)
|-
|X-component of the rotation axis of the Box placement
|{{incode|Box.Placement.Rotation.Axis.x}}
|X-component of the unit vector in mm without units
|-
|Rotation angle of the Box placement
|{{incode|Box.Placement.Rotation.Angle}}
|Rotation angle with units (deg)
|-
|Full Box object
|{{incode|Box._self}}
|Object of type <Part::PartFeature>
|Object of type <Part::PartFeature>
|-
|-
Line 862: Line 1,219:
|Value of the {{PropertyData|Length}} property in e.g a Pad object, if the expression is used in e.g {{PropertyData|Length2}} in the same object.
|Value of the {{PropertyData|Length}} property in e.g a Pad object, if the expression is used in e.g {{PropertyData|Length2}} in the same object.
|}
|}

=== Cyclic dependencies ===

FreeCAD checks dependencies based on the relationship between document objects, not properties. This means that you cannot provide data to an object and query that same object for results. For example, even though there are no cyclic dependencies when the properties themselves are considered, you may not have an object which gets its dimensions from a spreadsheet and then display the volume of that object in the same spreadsheet. You have to use two spreadsheets, one to drive your model and the other for reporting.

As a workaround it is possible to display a cell range from the second spreadsheet in the first (or vice versa) by creating a [[Spreadsheet_Workbench#Cell_binding|cell binding]] with the {{MenuCommand|Hide dependency of binding}} option.

Another way to workaround cyclic dependencies is to hide the reference by using the {{incode|href}} or {{incode|hiddenref}} function for individual expressions, for example: {{incode|href(Box.Length)}}.

Please note that both mentioned workarounds should be used with caution, and that they do not work if the properties that are reported depend on dimensions that are driven from the same spreadsheet.
{{Top}}
{{Top}}
== Document-wide global variables ==
== Document-wide global variables ==
Line 871: Line 1,238:
It is possible (with limitations) to define a Property of an object in your current document (".FCstd" file) by using an Expression to reference a Property of an object contained in a different document (".FCstd" file). For example, a cell in a spreadsheet or the {{PropertyData|Length}} of a Part Cube, etc. in one document can be defined by an Expression that references the X Placement value or another Property of an object contained in a different document.
It is possible (with limitations) to define a Property of an object in your current document (".FCstd" file) by using an Expression to reference a Property of an object contained in a different document (".FCstd" file). For example, a cell in a spreadsheet or the {{PropertyData|Length}} of a Part Cube, etc. in one document can be defined by an Expression that references the X Placement value or another Property of an object contained in a different document.


A document's name is used to reference it from other documents. When saving a document the first time, you choose a file name; this is usually different from the initial default "Unnamed1" (or its translated equivalent). To prevent links being lost when the master document is renamed upon saving, it is recommended that you first create the master document, create a spreadsheet inside it, and save it. Subsequently, you can still make changes to the file and its spreadsheet but you should not rename it.
A document's name is used to reference it from other documents. When saving a document the first time, you choose a file name; this is usually different from the initial default "Unnamed1" (or its translated equivalent). To prevent links being lost when the master document is renamed upon saving, it is recommended that you first create the master document, create a spreadsheet inside it, and save it. Subsequently, you can still make changes to the file and its spreadsheet but you should not rename it.


Once the master document with the spreadsheet is created and saved (named), it is safe to create dependent documents. For example, assuming you name the master document {{incode|master}}, the spreadsheet {{incode|modelConstants}}, and give a cell an alias-name {{incode|Length}}, you can then access the value as:
Once the master document with the spreadsheet is created and saved (named), it is safe to create dependent documents. For example, assuming you name the master document {{incode|master}}, the spreadsheet {{incode|modelConstants}}, and give a cell an alias-name {{incode|Length}}, you can then access the value as:
Line 877: Line 1,244:
{{incode|master#modelConstants.Length}}
{{incode|master#modelConstants.Length}}


'''Note:''' that the master document must be loaded for the values in the master to be available to the dependent document.
Note that the master document must be loaded for the values in the master to be available to the dependent document.

Unfortunately, the integrated checker sometimes claims that a valid name doesn't exist. Continue typing anyway. When you have completed the full reference, the {{Button|OK}} button will become active.


Of course, it's up to you to load the corresponding documents later when you want to change anything.
Of course, it's up to you to load the corresponding documents later when you want to change anything.
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<span id="Known_issues_/_remaining_tasks"></span>
== Известные проблемы / нерешённые задачи ==
== Известные проблемы / нерешённые задачи ==


* The dependency graph is based on the relationship between document objects, not properties. This means that you cannot provide data to an object and query that same object for results. For example, even though there are no cyclic dependencies when the properties themselves are considered, you may not have an object which gets its dimensions from a spreadsheet and then display the volume of that object in the same spreadsheet. As a work-around use multiple spreadsheets, one to drive your model and the other for reporting.
* The expression parser does not handle parentheses well, and is unable to properly parse some expressions. For example: {{incode|<nowiki>=</nowiki> (A1 > A2) ? 1 : 0}} results in an error, while {{incode|<nowiki>=</nowiki> A1 > A2 ? 1 : 0}} is accepted. The expression {{incode|<nowiki>=</nowiki> 5 + ((A1>A2) ? 1 : 0)}} cannot be entered in any form.
* As stated above, unfortunately, the integrated checker sometimes claims that a valid name doesn't exist. Continue typing anyway. When you have completed the full reference, the {{Button|OK}} button will become active.
* FreeCAD does not yet have a built-in expression manager where all expressions in a document are listed, and can be created, deleted, queried, etc. But an addon is available: [https://github.com/gbroques/fcxref fcxref expression manager].
* FreeCAD does not yet have a built-in expression manager where all expressions in a document are listed, and can be created, deleted, queried, etc. But an addon is available: [https://github.com/gbroques/fcxref fcxref expression manager].
* Open bugs/tickets for Expressions can be found in the [https://freecadweb.org/tracker/set_project.php?project_id=4;20 FreeCAD Bugtracker Expressions category]
* Open bugs/tickets for Expressions can be found on [https://github.com/FreeCAD/FreeCAD/issues?q=is%3Aissue+is%3Aopen+label%3AExpressions GitHub].
{{Top}}
{{Top}}



Latest revision as of 10:00, 21 April 2024

Обзор

Некоторые свойства объектов могут быть определены с помощью математических выражений. В графическом интерфейсе счетчики или поля ввода свойств которые поддерживают выражения, содержат синий значок . Щелчок по значку или ввод знака равенства = вызывает редактор выражений для этого конкретного свойства.

Выражение FreeCAD - это математическое выражение, следующее за обозначениями стандартных математических операторов и функций, как описано ниже. Кроме того, выражение может ссылаться на другие свойства, а также использовать условные выражения. К числам в выражении может быть добавлена необязательная единица измерения.

В числах, для отделение целых цифр от десятичных, можно использовать запятую , или десятичную точку .. Когда используется такой разделитель (точка или запятая), за ним должна следовать хотя бы одна цифра. Таким образом, выражения 1.+2. и 1,+2, недопустимы, но 1.0 + 2.0 и 1,0 + 2,0 действительны.

Операторы и функции зависят от единиц измерения и требуют допустимых комбинаций единиц, если таковые имеются. Например, 2mm + 4mm является допустимым выражением, а 2mm + 4 - нет (причина в том, что выражение типа 1in + 4 люди обычно интерпретируют как 1 дюйм + 4 дюйма, но все единицы внутренне преобразуются в систему СИ, и система не может это угадать). В настоящее время распознаются такие единицы.

Some unit related errors can seem unintuitive, with expressions either being rejected or producing results that do not match the units of the property being set. Here are some examples:

1/2mm is not interpreted as half a millimeter but as 1/(2mm), resulting in: 0.5 mm^-1.

sqrt(2)mm is not valid because the function call is not a number. This has to be entered as sqrt(2) * 1mm.

Аргументы функции

Multiple arguments to a function may be separated by either a semicolon ; or a comma followed by a space , . In the latter case, the comma is converted to a semicolon after entry. When a semicolon is used, no trailing space is necessary.

Arguments may include references to cells in a spreadsheet. A cell reference consists of the cell's uppercase row letter followed by its column number, for example A1. A cell may also be referenced by using the cell's alias instead, for example Spreadsheet.MyPartWidth.

Ссылка на объект в выражении

As already shown above, you can reference an object by its ДанныеName. But you can also use its ДанныеLabel. In the case of a ДанныеLabel, it must be enclosed in double << and >> symbols, such as <<Label>>.

You can reference any property of an object. For example, to reference a Cylinder's height, you may use Cylinder.Height or <<Label_of_cylinder>>.Height.

For more information about referencing objects, see Reference to CAD data.

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Поддерживаемые константы

Поддерживаются следующие константные значения:

Constant Description
e Euler's number
pi Pi

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Поддерживаемые операторы

Поддерживаются следующие операторы:

Оператор Описание
+ Сложение
- Вычитание
* Умножение
/ Деление
% Остаток от деления
^ Возведение в степень

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Поддерживаемые функции

Основные математические функции

Поддерживаются следующие математические функции:

Функции тригонометрии

Trigonometric functions use degree as their default unit. For radians add rad following the first value in an expression. So e.g. cos(45) is the same as cos(pi rad / 4). Expressions in degrees can use either deg or °, e.g. 360deg - atan2(3; 4) or 360° - atan2(3; 4). If an expression is without units and needs to be converted to degrees or radians for compatibility, multiply by 1deg, or 1rad as appropriate, e.g. (360 - X) * 1deg; (360 - X) * 1°; (0.5 + pi / 2) * 1rad.

Функция Описание Допустимый диапазон значений
acos(x) Арккосинус -1 <= x <= 1
asin(x) Арксинус -1 <= x <= 1
atan(x) Арктангенс любое значение
atan2(x; y) Функция Atan2 of x/y любое значение, за исключением y = 0
cos(x) Косинус любое значение
cosh(x) Гиперболический косинус любое значение
sin(x) Синус любое значение
sinh(x) Гиперболический синус любое значение
tan(x) Тангенс любое значение, за исключением x = n*90, где n = целое число
tanh(x) Гиперболический тангенс любое значение
hypot(x; y) Сумма Пифагора (hypotинуза). Например, hypot(4; 3) = 5. x и y > 0
cath(x; y) Учитывая гипотенузу и одну сторону, возвращает другую сторону треугольника. Например, cath (5; 3) = 4. x и y > 0, x >= y

Экспоненциальные и логарифмические функции

Function Description Input range
exp(x) Exponential function all
log(x) Natural logarithm x > 0
log10(x) Common logarithm x > 0
pow(x; y) Exponentiation all
sqrt(x) Square root x >= 0
cbrt(x) introduced in version 0.21 Cubic root all

Функции округления, усечения и вычисления остатка от деления

Function Description Input range
abs(x) Absolute value all
ceil(x) Ceiling function, smallest integer value greater than or equal to x all
floor(x) Floor function, largest integer value less than or equal to x all
mod(x; y) Remainder after dividing x by y, sign of result is that of the dividend. all, except y = 0
round(x) Rounding to the nearest integer all
trunc(x) Truncation to the nearest integer in the direction of zero all

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Функции агрегирования и статистики

Aggregate functions take one or more arguments.

Individual arguments to aggregate functions may consist of ranges of cells. A range of cells is expressed as two cell references separated by a colon :, for example average(B1:B8) or sum(A1:A4; B1:B4). The cell references may also use cell aliases, for example average(StartTemp:EndTemp).

Поддерживаются следующие функции агрегирования:

Function Description Input range
average(a; b; c; ...) Average value of the arguments, same as sum(a; b; c; ...) / count(a; b; c; ...) all
count(a; b; c; ...) Count of the arguments, typically used for cell ranges all
max(a; b; c; ...) Maximum value of the arguments all
min(a; b; c; ...) Minimum value of the arguments all
stddev(a; b; c; ...) Standard deviation of the values of the arguments all
sum(a; b; c; ...) Sum of the values of the arguments, typically used for cell ranges all

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Операции со строками

Идентификация строк

Strings are identified in expressions by surrounding them with opening/closing double chevrons (as are labels).

In following example, "TEXT" is recognized as a string : <<TEXT>>

Объединение строк

Строки могут быть объединены с помощью символа "+".

Например строки <<МОЙ>> + <<ТЕКСТ>> будут объединены в "МОЙТЕКСТ".

Преобразование числа в строку

Числовые значения могут быть преобразованы в строки с помощью функции str:

str(Box.Length.Value)

Форматирование строк

Форматирование строк поддерживается с использованием (старого) Python способа в стиле %.

Сведения о всех %-спецификаторах, можно узнать из документации Python.

As an example, supposing you have a default 10mm-side cube named 'Box' (default FreeCAD naming), the following expression <<Cube length : %s>> % Box.Length will expand to "Cube length : 10.0 mm"

For more than one %-specifier use the following syntax: <<Cube length is %s and width is %s>> % tuple(Box.Length; Box.Width). Or use concatenation: <<Cube length is %s>> % Box.Length + << and width is %s>> % Box.Width. Both will expand to "Cube length is 10.0 mm and width is 10.0 mm".

Пример файла FreeCAD с применением форматирования строк доступен на форуме

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Функция Create

С помощью функции create в выражениях могут быть созданы следующие объекты :

  • Vector
  • Matrix
  • Rotation
  • Placement
Type Function Description
Tuple tuple(a; b; ...) Example: tuple(2; 1; 2)
List list(a; b; ...) Example: list(2; 1; 2)
Vector vector(x; y; z) Create a vector using three unit-less or Length unit values.

Example: vector(2; 1; 3)

create(<<vector>>; x; y; z)
Matrix
matrix(
  a11; a12; a13; a14;
  a21; a22; a23; a24;
  a31; a32; a33; a34;
  a41; a42; a43; a44
)
Create a 4x4 matrix in row-major order:

A minimum of 1 argument can be supplied such as matrix(1) which creates an identity matrix.

Example: matrix(1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16)

create(<<matrix>>; a11; a12; ...; a44)
Rotation rotation(axis; angle) Create a Rotation by specifying its axis (Vector) and angle (Angle unit or unit-less), or three Euler angles α, β, γ.

Examples:

  • rotation(vector(0; 1; 0); 45)
  • create(<<rotation>>; 30; 30; 30)
rotation(α; β; γ)
create(<<rotation>>; axis; angle)
create(<<rotation>>; α; β; γ)
Placement placement(base; rotation) Create a Placement with various parameters, including:
  • base: base location (Vector)
  • center: center location (Vector)
  • rotation: Rotation
  • axis: Rotation axis (Vector)
  • angle: Rotation angle (unit-less or Angle unit value)
  • matrix: Matrix

Examples:

  • placement(vector(2; 1; 3); rotation(vector(0; 0; 1); 45))
  • create(<<placement>>; create(<<vector>>; 2; 1; 2); create(<<rotation>>; create(<<vector>>; 0; 1; 0); 45))
placement(base; rotation; center)
placement(base; axis; angle)
placement(matrix)
create(<<placement>>; ...)

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Vector functions

Functions: introduced in version 1.0.

Function / Operator Description
v1 + v2 Add two vectors.
v1 - v2 Subtract two vectors.
v * s Uniformly scale a vector by s.
vangle(v1; v2) Angle between two vectors in degrees.
vcross(v1; v2) Cross product of two vectors .
v1 * v2 Dot product of two vectors .
vdot(v1; v2)
vlinedist(v1; v2; v3) Distance between vector v1 and a line through v2 in direction v3.
vlinesegdist(v1; v2; v3) Distance between vector v1 and the closest point on a line segment from v2 to v3.
vlineproj(v1; v2; v3) Project vector v1 on a line through v2 in direction v3.
vnormalize(v) Normalize a vector to a unit vector.
vplanedist(v1) Distance between vector v1 and a plane defined by a point v2 and a normal v3.
vplaneproj(v1) Project vector v1 on a plane defined by a point v2 and a normal v3.
vscale(v; sx; sy; sz) Non-uniformly scale a vector by sx in the X direction, sy in the Y direction, and sz in the Z direction.
vscalex(v; sx)
vscaley(v; sy)
vscalez(v; sz)

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Matrix functions

Rotation and Placement can each be represented by a Matrix. The following functions all take in a Matrix, Rotation, or Placement as their first parameter denoted in the table below by m. The type of the returned object is the same as the object supplied in the first argument except when using mtranslate on a Rotation, in which case a Placement will be returned.

Function Description
minvert(m) Calculate the Inverse matrix.
mrotate(m; rotation) Rotate by either:
  • a Rotation
  • an axis (Vector) and an angle (Angle unit or unit-less)
  • three Euler angles α, β, γ
mrotate(m; axis; angle)
mrotate(m; α; β; γ)
mrotatex(m; angle) Rotate around the X axis.
mrotatey(m; angle) Rotate around the Y axis.
mrotatez(m; angle) Rotate around the Z axis.
mtranslate(m; vector) Translate by a vector (Vector) or X, Y, Z values. If a Rotation is translated, the returned object is a Placement.
mtranslate(m; x; y; z)
mscale(m; vector) Scale by a vector (Vector) or X, Y, Z values.
mscale(m; x; y; z)

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Условные выражения

Conditional expressions are of the form condition ? resultTrue : resultFalse. The condition is defined as an expression that evaluates to either 0 (false) or non-zero (true).

The following relational operators are defined:

Unit Description
== equal to
!= not equal to
> greater than
< less than
>= greater than or equal to
<= less than or equal to

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Единицы измерений

Units can be used directly in expressions. The parser connects them to the previous value. So 2mm or 2 mm is valid while mm is invalid because there is no preceding value.

All values must have a unit. Therefore you must in general use a unit for values in spreadsheets.
In some cases it works even without a unit, for example if you have e.g. in spreadsheet cell B1 just the number 1.5 and refer to it for a pad height. This only works because the pad height predefines the unit mm that is used if no unit is given. It will nevertheless fail if you use for the pad height e.g. Sketch1.Constraints.Width - Spreadsheet.B1 because Sketch1.Constraints.Width has a unit and Spreadsheet.B1 has not.

Units with exponents can directly be entered. So e.g. mm^3 will be recognized as mm³ and m^3 will be recognized as m³.

If you have a variable whose name is that of a unit you must put the variable between << >> to prevent it from being recognized as a unit. For example if you have the dimension Sketch.Constraints.A it would be recognized as the unit ampere. Therefore you must write it in the expression as Sketch.Constraints.<<A>>.

The following units are recognized by the expression parser:

Количество вещества

Unit Description
mmol Millimole
mol Mole

Угол

Единица измерения Описание
° Градус; тоже самое, что и deg
deg Градус; тоже самое, что и °
rad Радиан
gon Град
S Угловая секунда; тоже самое, что и ″
Угловая секунда; тоже самое, что и S
M Минута дуги; тоже самое, что и ′
Минута дуги; тоже самое, что и M

Ток

Unit Description
mA Milliampere
A Ampere
kA Kiloampere
MA Megaampere

Electric capacitance

Unit Description
pF Picofarad
nF Nanofarad
uF Microfarad; alternative to the unit µF
µF Microfarad; alternative to the unit uF
mF Millifarad
F Farad; 1 F = 1 s^4·A^2/m^2/kg

Electric charge

Электрический заряд:

Единица измерения Описание
C Кулон; 1 C = 1 A·s, представлено в версии 0.19

Electric conductivity

Unit Description
uS Microsiemens; alternative to the unit µS
µS Microsiemens; alternative to the unit uS
mS Millisiemens
S Siemens; 1 S = 1 s^3·A^2/kg/m^2
kS KiloSiemens
MS MegaSiemens

Electric inductance

Unit Description
nH Nanohenry
uH Microhenry; alternative to the unit µH
µH Microhenry; alternative to the unit uH
mH Millihenry
H Henry; 1 H = 1 kg·m^2/s^2/A^2

Electric potential

Электрический потенциал:

Единица измерения Описание
mV Милливольт
V Вольт
kV Киловольт

Electric resistance

Электрическое сопротивление:

Единица измерения Описание
Ohm Ом; 1 Ohm = 1 kg·m^2/s^3/A^2, представлено в версии 0.19
kOhm Килоом, представлено в версии 0.19
MOhm Мегаом, представлено в версии 0.19

Энергия/работа

Unit Description
mJ Millijoule
J Joule
kJ Kilojoule
eV Electronvolt; 1 eV = 1.602176634e-19 J
keV Kiloelectronvolt
MeV Megaelectronvolt
kWh Kilowatt hour; 1 kWh = 3.6e6 J
Ws Watt second; alternative to the unit Joule
VAs Volt-ampere-second; alternative to the unit Joule
CV Coulomb-volt; alternative to the unit Joule
cal Calorie; 1 cal = 4.184 J
kcal Kilocalorie

Сила

Единица измерения Описание
mN Миллиньютон
N Ньютон
kN Килоньютон
MN Меганьютон
lbf Фунт-сила(Английская единица)

Длина

Unit Description
nm Nanometer
um Micrometer; alternative to the unit µm
µm Micrometer; alternative to the unit um
mm Millimeter
cm Centimeter
dm Decimeter
m Meter
km Kilometer
mil Thousandth of an inch; alternative to the unit thou
thou Thousandth of an inch; alternative to the unit mil
in Inch; alternative to the unit "
" Inch; alternative to the unit in
ft Foot; alternative to the unit '
' Foot; alternative to the unit ft
yd Yard
mi Mile

Интенсивность света

Unit Description
cd Candela

Magnetic flux

Unit Description
Wb Weber; 1 Wb = 1 kg*m^2/s^2/A

Magnetic flux density

Unit Description
G Gauss; 1 G = 1 e-4 T
T Tesla; 1 T = 1 kg/s^2/A

Масса

Unit Description
ug Microgram; alternative to the unit µg
µg Microgram; alternative to the unit ug
mg Milligram
g Gram
kg Kilogram
t Tonne
oz Ounce
lb Pound; alternative to the unit lbm
lbm Pound; alternative to the unit lb
st Stone
cwt Hundredweight

Мощность

Unit Description
W Watt
kW Kilowatt

Давление

Unit Description
Pa Pascal
kPa Kilopascal
MPa Megapascal
GPa Gigapascal
uTorr Microtorr; alternative to the unit µTorr
µTorr Microtorr; alternative to the unit uTorr
mTorr Millitorr
Torr Torr; 1 Torr = 133.32 Pa
psi Pound-force per square inch; 1 psi = 6.895 kPa
ksi Kilopound-force per square inch

Температура

Unit Description
uK Microkelvin; alternative to the unit µK
µK Microkelvin; alternative to the unit uK
mK Millikelvin
K Kelvin

Время

Unit Description
s Second
min Minute
h Hour
Hz (1/s) Hertz
kHz Kilohertz,
MHz Megahertz
GHz Gigahertz
THz Terahertz

Объем

Unit Description
ml Milliliter
l Liter
cft Cubicfoot

Special imperial units

Unit Description
mph Miles per hour
sqft Square foot

Неподдерживаемые единицы измерения

The following commonly used units are not yet supported, for some an alternative is provided:

Unit Description Alternative
°C Celsius [°C] + 273.15 K
°F Fahrenheit; ([°F] + 459.67) × ​5/9
u Atomic mass unit; alternative to the unit Da 1.66053906660e-27 kg
Da Dalton; alternative to the unit u 1.66053906660e-27 kg
sr Steradian not directly
lm Lumen not directly
lx Lux not directly
px Pixel not directly

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Invalid characters and names

The expression feature is very powerful but to achieve this power it has some limitations concerning some characters. To overcome this, FreeCAD offers to use labels and reference them instead of the object names. In labels you can use almost all special characters.

In cases where you cannot use a label, such as the name of a sketch's constraints, you must be aware what characters are not allowed.

Labels

For labels there are no invalid characters, however some characters need to be escaped:

Characters Description
', \, " Need to be escaped by adding \ in front of them.

For example, the label Sketch\002 must be referenced as <<Sketch\\002>>.

Названия

Names of objects like dimensions, sketches, etc. may not have the characters or character sequences listed below, otherwise the name is invalid:

Characters / Character sequences Description
+, -, *, /, ^, _, <, >, (, ), {, }, [, ], ., ,, = Characters that are math operators or part of mathematical constructs
A, kA, mA, MA, J, K, ' , ft , °, and many more! Characters and character sequences that are units (see the Units paragraph)
#, !, ?, §, $, %, &, :, ;, \, |, ~, , ¿, and many more! Characters used as placeholder or to trigger special operations
pi, e Mathematical constants
´, `, ' , " Characters used for accents
space A space defines the end of a name and can therefore not be used

For example, the following name is valid: <<Sketch>>.Constraints.T2üßµ@. While these are invalid names: <<Sketch>>.Constraints.test\result_2 (\r means "carriage return") or <<Sketch>>.Constraints.mol (mol is a unit).

Since shorter names (especially if they have only one or two characters) can easily result in invalid names, consider using longer names and/or establishing a suitable naming convention.

Cell aliases

See Spreadsheet SetAlias.

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Reference to CAD data

It is possible to use data from the model itself in an expression. To reference a property use object_name.property or <<object_label>>.property, labels must be enclosed in << and >>. If you want to use labels they must be unique.

All next examples reference the object by its name, but in all cases the object label can also be used.

If the property is a compound of fields, the individual fields can be accessed as object_name.property.field.

To reference list objects use object_name.list[list_index]. If you want to reference a constraint in a sketch, use Sketch.Constraints[16]. If you are in the same sketch you may omit its name and just use Constraints[16]. Note that the index starts with 0, therefore Constraint17 has to be referenced as Constraints[16].

To reference the object itself use the _self pseudo property: object_name._self.

The following table shows some more examples:

CAD data Call in expression Result
Length of a Part Box Box.Length Length with units (mm)
Volume of the Box Box.Shape.Volume Volume in mm³ without units
Shape type of the Box Box.Shape.ShapeType String: Solid
Label of the Box Box.Label String: Label
X-coordinate of center of mass of the Box Box.Shape.CenterOfMass.x X-coordinate in mm without units
X-coordinate of the Box placement Box.Placement.Base.x X-coordinate with units (mm)
X-component of the rotation axis of the Box placement Box.Placement.Rotation.Axis.x X-component of the unit vector in mm without units
Rotation angle of the Box placement Box.Placement.Rotation.Angle Rotation angle with units (deg)
Full Box object Box._self Object of type <Part::PartFeature>
Value of constraint in a sketch Constraints.Width Numeric value of the named constraint Width in the sketch, if the expression is used in the sketch itself.
Value of constraint in a sketch MySketch.Constraints.Width Numeric value of the named constraint Width in the sketch, if the expression is used outside of the sketch.
Value of a spreadsheet alias Spreadsheet.Depth Value of the alias Depth in the spreadsheet Spreadsheet
Value of a local property Length Value of the ДанныеLength property in e.g a Pad object, if the expression is used in e.g ДанныеLength2 in the same object.

Cyclic dependencies

FreeCAD checks dependencies based on the relationship between document objects, not properties. This means that you cannot provide data to an object and query that same object for results. For example, even though there are no cyclic dependencies when the properties themselves are considered, you may not have an object which gets its dimensions from a spreadsheet and then display the volume of that object in the same spreadsheet. You have to use two spreadsheets, one to drive your model and the other for reporting.

As a workaround it is possible to display a cell range from the second spreadsheet in the first (or vice versa) by creating a cell binding with the Hide dependency of binding option.

Another way to workaround cyclic dependencies is to hide the reference by using the href or hiddenref function for individual expressions, for example: href(Box.Length).

Please note that both mentioned workarounds should be used with caution, and that they do not work if the properties that are reported depend on dimensions that are driven from the same spreadsheet.

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Document-wide global variables

There is no concept of global variables in FreeCAD at the moment. Instead, arbitrary variables can be defined as cells in a spreadsheet using the Spreadsheet workbench, and then be given a name using the alias property for the cell (right-click on cell). Then they can be accessed from any expression just as any other object property.

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Cross-document linking

It is possible (with limitations) to define a Property of an object in your current document (".FCstd" file) by using an Expression to reference a Property of an object contained in a different document (".FCstd" file). For example, a cell in a spreadsheet or the ДанныеLength of a Part Cube, etc. in one document can be defined by an Expression that references the X Placement value or another Property of an object contained in a different document.

A document's name is used to reference it from other documents. When saving a document the first time, you choose a file name; this is usually different from the initial default "Unnamed1" (or its translated equivalent). To prevent links being lost when the master document is renamed upon saving, it is recommended that you first create the master document, create a spreadsheet inside it, and save it. Subsequently, you can still make changes to the file and its spreadsheet but you should not rename it.

Once the master document with the spreadsheet is created and saved (named), it is safe to create dependent documents. For example, assuming you name the master document master, the spreadsheet modelConstants, and give a cell an alias-name Length, you can then access the value as:

master#modelConstants.Length

Note that the master document must be loaded for the values in the master to be available to the dependent document.

Of course, it's up to you to load the corresponding documents later when you want to change anything.

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Известные проблемы / нерешённые задачи

  • FreeCAD does not yet have a built-in expression manager where all expressions in a document are listed, and can be created, deleted, queried, etc. But an addon is available: fcxref expression manager.
  • Open bugs/tickets for Expressions can be found on GitHub.

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