Saving For Loop Values Into a Matrix

for i = 0:0.1:1

for j = 0:0.1:1

if (i^2 + j^2) <= 1

u = (sqrt(i^2 + j^2))^3;

else (i^2 + j^2) > 0

u = 3*sqrt(i^2 + j^2 - 1)+1;

end

end

end

I am looking to store these u values in a matrix u, because I want to plot the surface of u. I am having a hard time storing these values in a matrix. Thanks in advance. I only want to look at u values from 0-1 also if that helps at all.

Answer 1

[Image Analyst]

Try this:

alli = 0:0.1:1
allj = 0:0.1:1
for k1 = 1 : length(alli)
    i = alli(k1);
    for k2 = 1 : length(allj)
        j = allj(k2);
        if (i^2 + j^2) <= 1
            u(k1, k2) = (sqrt(i^2 + j^2))^3;
        elseif (i^2 + j^2) > 0
            u(k1, k2) = 3*sqrt(i^2 + j^2 - 1)+1;
        end
    end
end
surf(u);
colorbar

[Jim Tom]

Thanks this is great!