How to change the color of a specific sub-bar in a 2-D bar graph

Hi there,

I have a 31x3-matrix where each column represent the number of IP signaled by a security-detection technique day-by-day. I want to plot it in a 2-D bar graph where for each x point, three columns have to be shown (the values of a raw of the matrix above) and the third column have to change color accordingly the values of another 31x1-vector. For example if

 data = [4, 2, 2; 9, 5, 6];
 difference = [0, 1];

are the matrix of the IP and the vector that determines the color of the third raw, I want the third column of the first day (2) is plotted in a color, let supposed it is green, and the third column of the secondo day (6) is plotted in another, let supposed it is red. I've already done some trials but all failed.

Thank you for your attention.

Answer 1

[Hugo]

You can do that by plotting each bar separately. For example, suppose that data is a matrix of 31 x 3 and that the colors for the third columns are in a matrix c of 31 x 1, then you could do

 bar((1:31)-.2,data(:,1),.15)
 hold on; 
 bar((1:31),data(:,2),.15)
 for ind=1:31, 
    bar(ind+.2,data(ind,3),.15,'FaceColor',c(ind,:)); 
 end

The first argument in bar is the position of the bars and the .15 there is the width that I chose (you can choose another one of course).

Hope this helps.

[Andrea]

When I red your solution I was skeptical about the results, because it talked about plotting each bar separately - but I was wrong ! The final results is exactly what I was locking for !

Thank you Hugo :)