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Functions

Programs can be created and run interactively. Programming a function is demonstrated in the following example of a function ttwo(x), which multiplies its argument by $2$. After the definition it can be used like any other Jasymca function.
>> function y=ttwo(x) y=2*x; end
>> ttwo(3.123)
ans = 6.246
Following the keyword function is the prototype with a return variable y. This replaces the construct return y of other programming languages.

If functions are to be reused later, they should be written to a textfile and saved somewhere in Jasymcas searchpath. The filename must be the function name extended by ``.m'', in the present example ttwo.m. In subsequent sessions the function ttwo can be used without separately loading the file. Several installed functions of Jasymca are provided using this mechanism.



Helmut Dersch
2009-03-15