Bar plot with two Y-axes

Hi all,

I need to plot data in a bar plot with two Y axis. Morevover the bar must be grouped, like in the following picture:

http://it.mathworks.com/help/releases/R2014b/examples/graphics/BarGraphof2DArrayExample_01.png

I have tried the following code but the result is far to be fine.

figure
a=rand(10,1)*100;
b=rand(10,1)*5;
[AX,H1,H2] =plotyy([1:10],a, [1:10]-0.5,b, 'bar', 'bar');
set(H1,'FaceColor','r')

the problems are:

• Item one: There are two overlapped x-axis, but I need only one.
• Item two: the bars are not each next to the other,

Thank you

best regards

[dpb]

I don't have time to play at the moment but I see two possible modes of attack

1) And probably(?) simplest -- put the data all in one array; scale them to fit on the one axes based on the desired scale for the two. Then put the second axes on manually with its scale for display only.

2) Make the x-axes commensurate; put the same number of bars in each but use NaN for the missing data in the LH/RH bars for the respective RH/LH axes.

Answer 1

[Orion]

Hi,

try this

figure
a=[rand(10,1)*100 zeros(10,1)  ];
b=[zeros(10,1)    rand(10,1)*5 ];
[AX,H1,H2] =plotyy([1:10],a, [1:10],b, 'bar', 'bar');
set(H1,'FaceColor','r') % a
set(H2,'FaceColor','b') % b

[pietro]

clever! :)

[dpb]

2) above w/ zeros rather than NaN...

[pietro]

Using Orion's method I cannot set the legend. Here an example:

figure
a=[rand(10,1)*100 zeros(10,1)  ];
b=[zeros(10,1)    rand(10,1)*5 ];
[AX,H1,H2] =plotyy([1:10],a, [1:10],b, 'bar', 'bar');
set(H1,'FaceColor','r') % a
set(H2,'FaceColor','b') % b
legend('Absolute','Percentage')

Running this code I get only two red entries in the legend. How may I solve it?

Answer 2

[dpb]

...I get only two red entries in the legend. How may I solve it?

Use the handles, Luke... :) You've faked which bars are to be seen but have duplicates so have to use the handles associated with the two bars only of the ones that are wanted to be observed. Hn are each 2-vectors; use the first of each --

hLgnd=legend([H1(1) H2(1)],'Absolute','Percentage');

[pietro]

Thank you, it works

[dpb]

So "ACCEPT" the answer...(and of course it "works" :) )

[pietro]

Hi dpb I've already accepted Orion's answer. I'm sorry.

[dpb]

Second answer to second question...

[Dirk]

How could you place error bars onto the plot above?

[dpb]

Depends on which release...HG2 broke the HG1 solution...here's a link to the issues... <barweb-in-2014b-doesn-t-work-any-more>

The links in the RH side in this case are useful as well...