histogram bins with different colors

Hello Everybody,

I'd be glad if you could help me in building a histogram with different color for each histogram bin.

Before asking, I've tried to define for loops and a matrix of colors, without succeding.

My problem is that T.ConstructionYear is a 1531 x 1 numeric vector, and I'd have a different color for each bin. I left auto mode for the number of bins choice.

I've also tried to write the function for just two bins.

Thanks in advance for the help.

h1 = histogram(T.ConstructionYear, 'FaceColor', 'b');
xlabel('ConstructionYear');
ylabel('Number of Bridges');
title('Distribution of Construction Year Data');

Answer 1

[Scott MacKenzie]

I'm not sure if you can do this with histogram. Here's what I put together using histcounts and bar instead:

d1 = rand(1531,1); % put your T.ConstructionYear data here

myColor = rand(10,3); % 10 bins/colors with random r,g,b for each

d2 = histcounts(d1);  
b = bar(d2, 'facecolor', 'flat');
b.CData = myColor;
xlabel('ConstructionYear');
ylabel('Number of Bridges');
title('Distribution of Construction Year Data');

[Giuseppe Degan Di Dieco]

Dear Scott,

thanks for your reply and help.

I saw various posts before posting mine, but weren't so clear.

I'll try your solution and will let you know; I owe you a favour then.

I'll also search for the documentation about the functions you used.

Best regards, and thanks againg.

[Giuseppe Degan Di Dieco]

Dear Scott,

I've tried your solution and it works!

Thanks a lot, also because in a few lines you gave me many insights of computations, such as the histcounts and bar functions, and of coding, defining a vector with random values.

My very best wishes.

[Giuseppe Degan Di Dieco]

Dear @Scott MacKenzie,

hope you're still reading this thread, just to thank you again for your teaching;

it made me realised the below graph.

Best from Bristol.

[Scott MacKenzie]

Yup. Still getting threads here. Nice work. Congratulations. Arch masonry bridges rule! :)

You've got a lot going on in that chart. Are you using "full screen"? You can do this using

f = gcf;
f.WindowState = 'maximize'; % full screen

You can also play with the size of the tick label fonts using the axis FontSize property. Good luck.

[Giuseppe Degan Di Dieco]

Thanks Scott!

Wow, with your tip I got a figure that occupies the entire screen.

I didn't know it.

Best!

Answer 2

[Giuseppe Degan Di Dieco]

As a follow up to this thread, I've developed the below script to show the legend of multiple bars.

I've found some posts on this wonderful community, and then put them together.

%How to have a legend for each bin. For starting, trial with two bins and
%with a for loop
d1 = rand(2, 1); %a random-value 2 x 1 vector
myColor = rand(2, 3); %2 bins/color triplet with random r, g, b for each
d2 = histcounts(d1); %apply the histcounts function to the data
hold on
for i = 1:length(d1)
    b = bar(d1(i), d2);
    b.CData(i, :) = myColor(i, :);
end
b.BarWidth = 0.4;
xlabel('Construction Year');
ylabel('Number of Bridges');
title('Distribution of Construction Year Data');
legend('location', 'bestoutside')
hold off