Classic Fourier Series

[salvomic]

(02-01-2015 08:37 PM)Snorre Wrote:  Hello Salvo,

you're right. ...
You could put your choose box in a non-exported (private) PPL-function within the same program and call it like <programname>.<funcname>:
...

ok!
I'm trying this code:

Code:


ChooseInterval()
BEGIN
  LOCAL choice;
  CHOOSE(choice,"Intervallo","from -pi to pi","from 0 to pi");
  RETURN choice;
END;


#cas
fourcoeff(args):=
// Coefficienti di fourier formula normale
// input funzione fourcoeff(func, k) o espressione funcoeff(expr, var, k)
BEGIN
local argv,argc,f,k;
local ak, bk, a0, a1, b1;
argv:=[args];
argc:=size(argv);
f := argv(1);
k := argv(argc);
IF argc=3 THEN f:=zip('unapply', f, argv(2)); END;
ak:=(int(f(t)*cos(k*t),t,-pi,pi))/pi;
bk:=(int(f(t)*sin(k*t),t,-pi,pi))/pi;
a0:=(int(f(t),t,0,2*PI))/(2*PI);
a1:=(int(f(t)*cos(k*t),t,0,2*PI))/PI;
b1:=(int(f(t)*sin(k*t),t,0,2*PI))/PI;
IF FourCoeff.ChooseInterval()=1 THEN 
return  {ak, bk}; ELSE  
return {a0, a1, b1};
END;

END;
#end

but it doesn't execute any Choice, always give a0, a1, b1, the last option (ELSE)...
The program name here is FourCoeff, its function fourcoeff(args)

Can you help me to find the last error, please?
For the rest it should be ok...