MaplePrimes - answers and comments on Question, plotting region between two functions

transform

Robert Israel — Tue, 13 Dec 2011 03:24:58 Z

This has been discussed here a number of times. My favourite technique is

> f:= x^2-1: g:= -x-1;
plottools:-transform(unapply([x,y+g],x,y))(plot(f-g,x=-1.5 .. 1.5,filled=true));

crisp

acer — Tue, 13 Dec 2011 04:48:00 Z

Fantastic, thanks.

acer

the "multiplication" of the command transform with the command plot

herclau — Tue, 13 Dec 2011 18:26:51 Z

This syntax, ie the "multiplication" of the command transform with the command plot, is not exemplified by the help of Maple. Is there a link or post block which comment?

functional

acer — Wed, 14 Dec 2011 02:50:26 Z

@herclau

What Robert has done is construct a transformation procedure, using plottools:-transform, and then apply it to a plot structure. It is procedure application, not multiplication.

Done in steps, it might look like this,

f := x^2-1:
g := -x-1:

origplot:=plot(f-g, x=-1.5 .. 1.5,
               filled=true, color=COLOUR(RGB,.8,.8,.9)):
origplot;

H := unapply([x,y+g],x,y);

transformer := plottools:-transform(H):

transformer(origplot);

plots:-display(
  plot([f,g], x=-1.5 .. 1.5, color=black),
  %
               );

Origin

Markiyan Hirnyk — Wed, 28 Mar 2012 10:02:32 Z

This version originates from Alec Mihailovs' post http://www.mapleprimes.com/posts/43748-How-To-Color-A-Region . Robert Israel uses it without any reference.