I got error in plotting

Hi everyone,

I tried to plot a figure by contour command and after I defined a set command for make changing on K values but ,when I run it, I got a figure that is not my preferred shape. of course, if I defined "set" function as set(d,'levelstep',30); , I got a right figure and, at this time, below error has occurred.

Undefined function or variable 'k'.

Error in projetmatlab (line 10)
set(k,'levelstep',30);

my code is as follow:

 close all
 clear
 clc
 x=linspace(-4,4,200);
 y=x;
 [X, Y]=meshgrid(x,y);
 V=1./sqrt((X-1).^2+(Y).^2+eps)-1./sqrt((X+1).^2+Y.^2+eps);
 [Ex, Ey]=gradient(V);
 [C, K]=contour(X,Y,V,[-2:0.1:2]);
 set(k,'levelstep',30);
 [C1, h]=contour(X,Y,sqrt(Ex.^2+Ey.^2),[0:0.01:0.5]);

so what is wrong?

Answer 1

[KSSV]

close all
 clear
 clc
 x=linspace(-4,4,200);
 y=x;
 [X, Y]=meshgrid(x,y);
 V=1./sqrt((X-1).^2+(Y).^2+eps)-1./sqrt((X+1).^2+Y.^2+eps);
 [Ex, Ey]=gradient(V);
 [C, K]=contour(X,Y,V,[-2:0.1:2]);
 set(K,'levelstep',30);
 [C1, h]=contour(X,Y,sqrt(Ex.^2+Ey.^2),[0:0.01:0.5]);

In the set command it shall be 'K' (capital), you typed 'k' (small case)