plotting a parametric integral



On Sex, 2009-10-09 at 02:10 +0400, Stanislav Maslovski wrote:

> I am trying to plot this simple Fourier integral in Maxima 5.17.1:

> (%i2) f(k):=integrate(exp(%i*k*x)*sin(x)/x,x,minf,inf)$

> (%i4) plot2d(f,[x,-3,3]);

Hi,
as Mario has already pointed out, the problem is that plot2d is passing
a symbol %pi to the plotting program, where it should pass a
floating-point approximation to %pi. Try the following:

(%i2) f(k):=float(integrate(exp(%i*k*x)*sin(x)/x,x,minf,inf))$

(%i4) plot2d(f,[x,-3,3],[y,-1,4]);

(if you don't use the "y" option, part of your plot will be covered by
the plot box.)

Regards,
Jaime Villate