Plotting family of functions



> Somewhere I've seen how to plot a family of functions but I've
forgotten the exact notation.

No special notation necessary.  The plot2d function takes a list of
expressions (or functions) as its first argument.  You can construct a
list of expressions using makelist:

  makelist(sin(n*x),n,1,3) => [SIN(x),SIN(2*x),SIN(3*x)]

So:

  plot2d(makelist(sin(n*x),n,1,3),[x,0,2*%Pi]);

You can even do things like:

  plot2d(append(makelist(sin(n*x),n,1,3),
                makelist(cos(n*x),n,1,3)),
         [x,0,2*%Pi]);

or even

  plot2d(apply(append,makelist(makelist(f(n*x),n,1,3),
                               f,[sin,cos])),
         [x,0,2*%Pi]);

To make that easier to read, you can split it up as:

  plotlist: apply(append,makelist(makelist(f(n*x),n,1,3),
                               f,[sin,cos]));
  plot2d(plotlist,[x,0,2*%Pi]);

    -s