for loop for generate overlay bar graphs

I generated a bar graph of the following type:

load matrix.mat
matrix = matrix(1:2,:);

x = matrix(:,1)';

wR = 0.5;
wB = 0.6;
wG = 0.7;
wT = 0.8;

temp_R = matrix(:,2);
temp_B = matrix(:,3);
temp_G = matrix(:,4);
temp_T = matrix(:,5);


figure
barh(x,temp_T,wT,'FaceColor',[1,0,0.52])

hold on
barh(x,temp_G,wG,'FaceColor',[0,1,0])
barh(x,temp_B,wB,'FaceColor',[0,0,1])
barh(x,temp_R,wR,'FaceColor',[1,0,0])
hold off

I need to transform it so that the graph becomes this:

I tried the following code but it only works correctly for the last row of 'matrix' (i.e., for the value 67 on the vertical axis).

figure
barh(x,temp_T,wT,'FaceColor',[1,0,0.52])        

for K = 1:height(matrix)
    matrix_only_row = matrix(K,:);
    
    if matrix_only_row(1,2) > ( matrix_only_row(1,3) && matrix_only_row(1,4) )
    
        if matrix_only_row(1,3) > matrix_only_row(1,4)
    
            hold on
            wR = 0.7;
            barh(x,temp_R,wR,'FaceColor',[1,0,0])
            wB = 0.6;
            barh(x,temp_B,wB,'FaceColor',[0,0,1])
            wG = 0.5;
            barh(x,temp_G,wG,'FaceColor',[0,1,0])   
            hold off
    
        elseif matrix_only_row(1,4) > matrix_only_row(1,3)
            
            hold on
            wR = 0.7;
            barh(x,temp_R,wR,'FaceColor',[1,0,0])
            wG = 0.6;
            barh(x,temp_G,wG,'FaceColor',[0,1,0])
            wB = 0.5;
            barh(x,temp_B,wB,'FaceColor',[0,0,1])
            hold off
    
        end   
    
    end

end

What do I need to modify to get the desired result?

If there is a more direct way it is appreciated.

Answer 1

[Voss]

Here's one way, using patches instead of barh:

load matrix.mat

[data,idx] = sort(matrix(:,2:end),2,'descend');
[n,m] = size(data);

colors = [1 0 0; 0 0 1; 0 1 0; 1 0 0.52];

max_bar_width = 0.8;
min_bar_width = 0.5;
bar_widths = linspace(max_bar_width,min_bar_width,m);

for ii = 1:n
    for jj = 1:m
        patch([0 0 data(ii,jj)*[1 1] 0],matrix(ii,1)+bar_widths(jj)*0.5*[-1 1 1 -1 -1],colors(idx(ii,jj),:));
    end
end

[Alberto Acri]

Hi @Voss. Is it possible to change the width of the bars? In the code it goes from 0.8 down to 0.5 (so 0.8 - 0.7 - 0.6 - 0.5). I would like to be able to change the width of the bars so that we have 0.9 - 0.7 - 0.5 - 0.3 (step of 2 and not 1).

[Voss]

Yes, simply use:

max_bar_width = 0.9;
min_bar_width = 0.3;
bar_widths = linspace(max_bar_width,min_bar_width,m);

[Alberto Acri]

Okay, thank you. And one more question.

I put the legend to the chart but the colors in the legend do not match the colors entered in 'colors':

legend('SECTION 1', 'SECTION 2', 'SECTION 3', 'SECTION 4', 'Location','southeast')

The colors are correct when the bar graph is created, but they are not correct in the legend.

They must be:

• red for SECTION 1
• blue for SECTION 2
• green for SECTION 3
• magenta for SECTION 4

[Voss]

load matrix.mat

[data,idx] = sort(matrix(:,2:end),2,'descend');
[n,m] = size(data);

colors = [1 0 0; 0 0 1; 0 1 0; 1 0 0.52];

max_bar_width = 0.9;
min_bar_width = 0.3;
bar_widths = linspace(max_bar_width,min_bar_width,m);

p = zeros(n,m);
for ii = 1:n
    for jj = 1:m
        p(ii,idx(ii,jj)) = patch([0 0 data(ii,jj)*[1 1] 0],matrix(ii,1)+bar_widths(jj)*0.5*[-1 1 1 -1 -1],colors(idx(ii,jj),:));
    end
end

legend(p(1,:),'SECTION 1', 'SECTION 2', 'SECTION 3', 'SECTION 4', 'Location','southeast')

[Alberto Acri]

Perfect! Is there also a way to do the same thing using barh?

[Voss]

load matrix.mat

[data,idx] = sort(matrix(:,2:end),2,'descend');
[n,m] = size(data);

colors = [1 0 0; 0 0 1; 0 1 0; 1 0 0.52];

max_bar_width = 0.9;
min_bar_width = 0.3;
bar_widths = linspace(max_bar_width,min_bar_width,m);

hold on
b = zeros(n,m);
for ii = 1:n
    for jj = 1:m
        b(ii,idx(ii,jj)) = barh(matrix(ii,1),data(ii,jj),bar_widths(jj),'FaceColor',colors(idx(ii,jj),:));
    end
end

legend(b(1,:),'SECTION 1', 'SECTION 2', 'SECTION 3', 'SECTION 4', 'Location','southeast')