How to change the legend color?

n = 2/3;
A = 1;
r = linspace(0,0.4,30);
th = linspace(0,2*pi,100);
[R, TH] = meshgrid(r,th);
fi = A*R.^n.*cos(n*TH);
zi = A*R.^n.*sin(n*TH);
[X,Y] = pol2cart(TH,R);
contour(X,Y,fi,'r')
hold on
contour(X,Y,zi,'b')
hold off
xlabel x-axis
ylabel y-axis
title('n = 2/3: flow around a right corner')
legend('\phi','\psi')

Answer 1

[Star Strider]

First, create a handle to the legend object, then change whatever properties you want using the options in Legend Properties.

Example (with your code) —

n = 2/3;
A = 1;
r = linspace(0,0.4,30);
th = linspace(0,2*pi,100);
[R, TH] = meshgrid(r,th);
fi = A*R.^n.*cos(n*TH);
zi = A*R.^n.*sin(n*TH);
[X,Y] = pol2cart(TH,R);
contour(X,Y,fi,'r')
hold on
contour(X,Y,zi,'b')
hold off
xlabel x-axis
ylabel y-axis
title('n = 2/3: flow around a right corner')
hl = legend('\phi','\psi');
set(hl, 'TextColor','r', 'Color','g', 'EdgeColor','b')

Experiment to get the result you want.

[Myo Gyi]

Thank You Sir...

But I want to change the color of contour only sir...red color and blue cour

[Star Strider]

To change the colour of the contour requires that you change the colour in the contour function, that you already appear to be doing in your contour calls:

contour(X,Y,fi,'r')

creating a red contour, and:

contour(X,Y,zi,'b')

creating a blue contour.

The colours in the legend will be the same as those you designated in the contour calls.

Please describe in some detail what you actually want to do. What result do you want?

[Myo Gyi]

I want to change the this knid of color of coutour Sir... But I don't know how can I do it.

[Star Strider]

I am having a difficult time following what you want to do.

Try this:

contour(X,Y,fi,'g')

and:

contour(X,Y,zi,'g')

You cannot change the colour in the legend to be different from the colour you defined in the contour calls.

[Myo Gyi]

Thank You Sir....No problem for this color...But I want to try for the best... Thanks a lot sir

[Star Strider]

My pleasure.

If my Answer helped you solve your problem, please Accept it!