How can one specify the color of comparison bar chart?

Suppose I have

bin_age = ['test', 2];
vals = [ 1 1; 2 2];

b = bar(vals)
newXticklabel = {'young', 'old'}
set(gca,'XtickLabel',newXticklabel);
xlabel('Product');

How can one change the colors of the first bars (blues) and the second bars (oranges)?

Answer 1

[dpb]

Just answered for another a few minutes ago @ <problem-with-grouped-bar-plot>

You also have a grouped bar plot as your data are arranged as a 2x2 array -- so 2 groups of 2 bars/group.

The .CData property is the only way to change individual bars, likewise it's the way to change all bars of the two bar handles because as you've probably already discovered, the 'Color' property in the bar() argument list is applied to every bar globally, and there's no provision to supply a vector of colors to associate with each row (group) on a 1:1 basis.

I've railed at TMW for 30 years about the poor interface to bar() on such things that the implementation is extremely "user-beligerent" as opposed to "user-friendly".

[alpedhuez]

Would you give me the code sample? Thank you.

[dpb]

<Customize One Series in Grouped or Stacked Bars> is the example code -- your case is just a tiny bit simpler than the one referenced before as you want to change the colors of all the bars in each group, not each bar individually within groups.

Hence, you can set the .FaceColor property directly to the desired color triplet -- or, if you're satisfied with one of the default color names, you can also use one of them although the example doesn't show that.

b(2).FaceColor='k';

would turn the second set black, for example.

[alpedhuez]

You are doing a God's work.

[dpb]

Well, that's probably a little overblown...but thanks! Try to help.

In this case it is in the TMW documentation if one digs deeply enough into all the examples -- although will admit that there is a lot of documentation and one's eyes may glaze over before finding what are looking for -- or "the newbie" may just not recognize the answer is there all along being inexperienced as yet.

[alpedhuez]

I did talk to a tech support.

[dpb]

Oh, really! That IS surprising, indeed.