MaplePrimes - answers and comments on Question, How to plot a function under constraint

By procedure

hirnyk — Fri, 04 Mar 2011 17:07:40 Z

A very similar question was asked a few months ago. It can be done as follows.
> f := proc (m, lambda) if 0 < (m+lambda)*20.004936*(1-sqrt(lambda*m))-3*lambda then 0.1281008386e-3*m*lambda*(20.004936*lambda+21.004936*m+1)^2/(m+lambda)^2+0.1281008386e-3*(21.004936*lambda+21.004936*m-m*(1-lambda))^2/(m+lambda)^2-0.2690752038e-2-0.2690752038e-2*m*lambda end if end proc;
> with(plots): plot3d(f, .1 .. 1, .1 .. 1, axes = box, numpoints = 100000, style = surface);

Puzzling combined plot of restricted and not restricted function

res assistant1 — Fri, 04 Mar 2011 20:58:11 Z

Dear hirnyk1222,

Thanks for your answer!

I have one more question.

In the procedure I have added one more constraint (lambda>(1/2+m)). When I conbine the plot of the general function (without restriction) with the plot of the restricted function, the area of the restricted function lies outside the area of the general function which should not be possible. As normally speaking one would expect the area of the restriced function to fall in the certain part of the are of the general function.

Do you have any idea what went wrong? Please have a look at the maple file attached Constraints_done_for.mw.

Thank you in advance,

Olga

Two changes

hirnyk — Fri, 04 Mar 2011 22:10:20 Z

@res assistant1 If we increase numpoints and replace lambda and m in the parameters of the procedure f:=proc(m,lambda)... end proc (The constraints (Edit. and the function d) are not symmetric in m and lambda.), then that's all right. See adjustedConstraints_.mw

as Maple 9.5

Axel Vogt — Thu, 10 Mar 2011 02:06:26 Z

Did not look closer, but here in Maple 9.5 (as you ask in a branch to this thread - plot3d is different) what hirnyk said, as attached zipped sheet

To avoid the graph is dropping to zero level: should be through your if ... without else, may be else NULL can help

adjustedConstraints_.zip

PS: No need to branch into a new thread ...

PPS: how ugly, that cutting down filenames to only some characters does not allow to distinguish on the local machine - can one finitely remove that technical nonsense?