how to plot the 3d graph

 dgh:= 0.09954;
 Delta:=-0.68429;
 sx:=-0.01098;
 sy:= 0.05126;
 Esup:=sx*x+sy*y+dgh*((x^2+y^2)/2+Delta*(x^2-y^2)/2)^(1/2);
 Einf:=sx*x+sy*y-dgh*((x^2+y^2)/2+Delta*(x^2-y^2)/2)^(1/2);
how to plot the graphs of the two functions in the same plot.

[Walter Roberson]

Please confirm that you want to plot within a MuPad notebook and not within MATLAB.

[Sarah Palfreyman]

Have you seen the fplot family of functions in R2016a?

Answer 1

[John BG]

Hi Akshaya

the straight way to visualize the function boundaries is, for Esup

dgh= 0.09954;
  Delta=-0.68429;
  sx=-0.01098;
  sy= 0.05126;
  x=[-20:1:20];y=[-20:1:20]
  [X,Y]=meshgrid(x,y)
  Esup=sx*X+sy*Y+dgh*(abs((X.^2+Y.^2)/2+Delta*(X.^2-Y.^2)/2)).^.5
  figure(1);surf(X,Y,Esup)

and Einf:

figure(2);surf(X,Y,Einf)

I had to add the abs() otherwise the boundaries showed complex values when attempting to solve sqrt of negative values.

To plot both boundaries in same graph use command hold:

figure(1);hold all;surf(X,Y,Einf)

If you find this answer of any help solving your question, please click on the thumbs-up vote link,

thanks in advance

John

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