Programmer Guide/Command Reference/EVAL/mul: Difference between revisions

From STX Wiki
Jump to navigationJump to search
No edit summary
No edit summary
Line 1: Line 1:
{{DISPLAYTITLE:mul (alias: "x*y")}}
{{DISPLAYTITLE:mul (alias: "x*y")}}
Compute the inverse of ''x''.  
Compute the inverse of ''x''.  
;Usage:  
;Usage: '''<code>mul(''x'', ''y'')</code>'''
:{|class="keinrahmen"
;Result: If both arguments ''x'' and ''y'' are vectors, the tensor (or dyadic) product of the vectors is computed and the result ''r'' is a matrix with <code>nrow(''x'')</code> rows and <code>nrow(''y'')</code> columns.
|'''<code>inv(''x<sub>scalar</sub>)</code>'''
::<code>''r''<sub>i,j</sub> = ''x''<sub>i</sub> * ''y''<sub>j</sub></code>
|-
:For all other combinations of data types, the [[Programmer_Guide/Command_Reference/EVAL#Operators|operator *]] is applied to ''x'' and ''y'' and the product <code>''x''*''y''</code> is returned. If the multiplication is not possible (e.g. invalid combination of data types), the function <code>mul</code> failes.
|'''<code>inv(''x<sub>matrix</sub>)</code>'''
|-
|}
;Result: The result has the same type as the argument ''x'' and is the inverse of ''x''. The argument ''x'' must be a scalar or a square matrix.
;Note: This function can be used as alias for the [[Programmer_Guide/Command_Reference/EVAL#Operators|operator *]], which do not implement the dyadic product. both arguments ''x'' and ''y'' are vectors, the dyadic product is computed, otherwise the [[Programmer_Guide/Command_Reference/EVAL#Operators|operator *]] is applied to ''x'' and ''y''.


;See also: [[Programmer_Guide/Command_Reference/EVAL/trn|trn]], [[Programmer_Guide/Command_Reference/EVAL/inv|inv]], [[Programmer_Guide/Command_Reference/EVAL/complex arithmetic#special functions|ctrn, cmulv]],  
;See also: [[Programmer_Guide/Command_Reference/EVAL/trn|trn]], [[Programmer_Guide/Command_Reference/EVAL/inv|inv]], [[Programmer_Guide/Command_Reference/EVAL/complex arithmetic#special functions|ctrn, cmulv]],  


[[Programmer_Guide/Command_Reference/EVAL#Functions|<function list>]]
[[Programmer_Guide/Command_Reference/EVAL#Functions|<function list>]]

Revision as of 15:05, 8 April 2011

Compute the inverse of x.

Usage
mul(x, y)
Result
If both arguments x and y are vectors, the tensor (or dyadic) product of the vectors is computed and the result r is a matrix with nrow(x) rows and nrow(y) columns.
ri,j = xi * yj
For all other combinations of data types, the operator * is applied to x and y and the product x*y is returned. If the multiplication is not possible (e.g. invalid combination of data types), the function mul failes.
See also
trn, inv, ctrn, cmulv,

<function list>

Retrieved from "https://mediawiki.kfs.oeaw.ac.at/stx/docs/wiki/index.php?title=Programmer_Guide/Command_Reference/EVAL/mul&oldid=3273"

Navigation menu

Personal tools