New package for drawing direction fields with gnuplot
Subject: New package for drawing direction fields with gnuplot
From: Mark H Weaver
Date: Sat, 20 Nov 2010 08:07:47 -0500
Robert Dodier wrote:
> Evaluating f(x, y) with symbolic arguments triggers the error. Try
> postponing evaluation of f, e.g. drawdf(f, ...) (not sure if that works)
> or drawdf('(f(x, y)), ...).
Adam Majewski <adammaj1 at o2.pl> wrote:
> (%i10) drawdf('f(x,y), [x,-2,2], [y,-2,2]);
> draw: graphical 2d object errexp1 is not recognized
'(f(x,y)) is not the same as 'f(x,y). The first quotes the entire
subexpression. The second uses the noun form of f.
Passing '(f(x,y)) to drawdf works. Passing f or 'f(x,y) fails.
Mark