create multiple figures of patches with random colors

I'm trying to create a number of patches with different colors using a random number function and all of the regular colors in MATLAB (i.e. g,r,b etc). I'm using a 'for' loop and assigning a new color to the patch each time but for some reason the script returns patches with the same color every time. The section of scripts i'm using now is:

    for i=1:12
     figure

    col_list='ymcrgbk';
        col=randi([1,7],1);
        random_color=col_list(col);

        patch_x=[0 2 2 0]
        patch_y=[0 0 2 2]

        final_color=['-' random_color]
        patch(patch_x,patch_y,'final_color');

    end

[Stephen23]

Note that operations which do not depend on the loop variable should be moved outside of the loop. For example it would be much more efficient to call randi just once before the loop rather than multiple times inside the loop.

Also note that using i or j as the loop variable is not recommended as it is the name of the inbuilt imaginary unit.

See my answer for a more efficient way of writing a loop like this.

[Declan Bourke]

That's great, i will make a note for the future and stop using i for the loop variable.

Thanks for the advice,

Declan

Answer 1

[Stephen23]

N = 12;
vec = 'ymcrgbk';
clr = vec(randi(numel(vec),N));
figure
for k = 1:N
    X = [0,2,2,0]+k;
    Y = [0,0,2,2];
    patch(X,Y,clr(k));
end

[Declan Bourke]

tried it and worked. thanks for the help!

[Lina KORONFEL]

Thank you!

Answer 2

[KSSV]

clc; clear all ;
for i=1:12
     figure
    col_list='ymcrgbk';
        col=randi([1,7],1);
        random_color=col_list(col) ;
        patch_x=[0 2 2 0] ;
        patch_y=[0 0 2 2] ;
        final_color=['-' random_color] ;
        patch(patch_x,patch_y,random_color);
end

[Declan Bourke]

tried and worked. thanks for your help!