Fwd: Maxima: How to plot "numerically" defined function?
Subject: Fwd: Maxima: How to plot "numerically" defined function?
From: Valery Pipin
Date: Fri, 12 Nov 2004 09:34:04 +0800
On Friday 12 November 2004 02:12, Barton Willis wrote:
> (%i1) f(x) := first(quad_qag(exp(-t^2),t,0,x,6))$
> (%i2) plot2d('(f(x)),[x,0,1])$
>
> Notice the '( ... ) surrounding f(x). Unfortunately, the compiler
> gets called once for every computed dot on the graph. Maybe
> romberg is better behaved.
>
> Barton
>
I get used
f(x) :='( first(quad_qag(exp(-t^2),t,0,x,6))
or
f(x) :='( quanc8(exp(-t^2),t,0,x,6)) (which is faster)
and
plot2d(float(f(x)),[x,0,1])$
The quanc8 is better for gcl. Plotiing is going witout annoying messages
about compilation(these messages are specific to gcl, I think). Also I found
that gcl is about one order faster over cmucl on the numerical integration.
Valery