VAL: Difference between revisions
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<code>VAL ( [[expression]] )</code> | <code>VAL ( [[expression]] )</code> | ||
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Try to find a value for the expression from any equations defined previously in the document. A value is | Try to find a value for the expression from any equations defined previously in the document. A value is expected to be a quantity, that is a number with optional units. If the expression cannot be reduced to a quantity, it will be reduced to numerical values as far as possible. | ||
The expression will contain rational numbers, not floats, unless a conversion to a floating point number is | The expression will contain rational numbers, not floats, unless a conversion to a floating point number is required to obtain a quantity. This might be the case e.g. if the expression contains square roots of rational numbers. If you want to force a conversion to floats in this case, use <code>[[QUANTITY]]</code> instead. | ||
If the expression cannot be evaluated to a quantity (e.g. some symbolic elements remain), then iMath will retain mathematical precision. For example, square roots will not be evaluated to floating point numbers. If you want this, use [[SIMPLIFY]] with the <code>eval</code> simplification. | |||
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[[QUANTITY]] [[QUANTITYWITH]] [[NUMVAL]] [[NUMVALWITH]] [[VALWITH]] [[UNIT]] [[UNITWITH]] | [[QUANTITY]] [[QUANTITYWITH]] [[NUMVAL]] [[NUMVALWITH]] [[VALWITH]] [[AVAL]] [[AVALWITH]] [[UNIT]] [[UNITWITH]] | ||
}} | }} | ||
[[Category:Evaluation]] | [[Category:Evaluation]] | ||
Latest revision as of 05:38, 24 July 2022
Syntax
VAL ( expression )
Implemented in iMath since version 2.2.0 or earlier.
Explanation
Try to find a value for the expression from any equations defined previously in the document. A value is expected to be a quantity, that is a number with optional units. If the expression cannot be reduced to a quantity, it will be reduced to numerical values as far as possible.
The expression will contain rational numbers, not floats, unless a conversion to a floating point number is required to obtain a quantity. This might be the case e.g. if the expression contains square roots of rational numbers. If you want to force a conversion to floats in this case, use QUANTITY instead.
If the expression cannot be evaluated to a quantity (e.g. some symbolic elements remain), then iMath will retain mathematical precision. For example, square roots will not be evaluated to floating point numbers. If you want this, use SIMPLIFY with the eval simplification.
Example
EQDEF a = 3 x
EQDEF b = 2 x
EQDEF x = 7 %metre
EXDEF VAL(a + b)
This will output 35 "m".
See also
QUANTITY QUANTITYWITH NUMVAL NUMVALWITH VALWITH AVAL AVALWITH UNIT UNITWITH