RE: ImplicitPlot and ContourPlot problem
- To: mathgroup at smc.vnet.net
- Subject: [mg38159] RE: [mg38119] ImplicitPlot and ContourPlot problem
- From: "David Park" <djmp at earthlink.net>
- Date: Wed, 4 Dec 2002 03:23:44 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Marco,
You probably meant that you tried:
ContourPlot[Sqrt[x - y], {x, 0, 10}, {y, 0, 10}];
That has problems because when x < y you have the square root of a negative
number, which gives an imaginary number.
You could, however, plot the real and imaginary parts of the function as
follows.
ContourPlot[Re[Sqrt[x - y]], {x, 0, 10}, {y, 0, 10}];
ContourPlot[Im[Sqrt[x - y]], {x, 0, 10}, {y, 0, 10}];
or the absolute value
ContourPlot[Abs[Sqrt[x - y]], {x, 0, 10}, {y, 0, 10}];
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
From: Marco [mailto:caiazzo at ieee.org]
To: mathgroup at smc.vnet.net
Hi,
I type the following:
ImplicitPlot[Sqrt[x-y]==0,{x,0,10}]
and all ok,
but if i try to use ContourPlot in the following manner
ImplicitPlot[Sqrt[x-y]==0,{x,0,10},{y,0,10}]
it say:
ContourGraphics::"ctpnt": "The contour is attempting to traverse a cell in
which some of the points have not evaluated to numbers, and it will be
dropped."
I have not understud why.
Some one can help me?
Thanks.