Holding legend in boxplots

Anbazhagan

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Apr 12, 2010, 9:26:04 AM4/12/10

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I am plotting two boxplots in one figure using hold on in matlab 7.1. Legend of the first boxplot gets lost when second one is plotted. How can i hold the legend as well? I

Walter Roberson

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Apr 12, 2010, 2:27:57 PM4/12/10

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Is it possible that the older legend is present but hidden underneath the
newer one? Did you specifically use different positions in the legend() function ?

Anbazhagan

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Apr 13, 2010, 1:11:04 AM4/13/10

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Walter Roberson <robe...@hushmail.com> wrote in message <hpvonf$11g$2...@canopus.cc.umanitoba.ca>...

yes. it is hidden underneath. Am using the 'best' position for both legends.

Walter Roberson

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Apr 13, 2010, 10:38:53 AM4/13/10

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Well, change your code so that you use different specific corners.
legend() does not look at the graphics drawn already in order to find
the best place: it only looks at the data values of the axis it is
associated with.

Anbazhagan

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Apr 13, 2010, 11:03:23 AM4/13/10

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Walter Roberson <robe...@hushmail.com> wrote in message <hq1vlt$ihc$2...@canopus.cc.umanitoba.ca>...

I tried your suggestion but the first legend flashes for a second and then disappears.
Then it displays only one legend but it is wrong i.e; it displays second boxplot legend text with the first boxplot line color.

I tried this approach but I receive an error
M={'Test A',Test B'};
p1=boxplot(bxplt_data2,'orientation','horizontal','label',bxplt_lbl,'colors','b','symbol','b+');
hold on
p2=boxplot(bxplt_data1,'orientation','horizontal','label',bxplt_lbl,'colors','r','symbol','r+');
legend([p1,p2],M);
*****************
Error:
??? Operands to the || and && operators must be convertible to logical scalar values.

Error in ==> legend at 198
elseif narg > 0 && ~ischar(varargin{1}) && ...
*****************
The above approach works well for the normal plots.
I dont know what I am doing wrong with boxplots.

Tom Lane

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Apr 13, 2010, 1:37:31 PM4/13/10

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> p1=boxplot(bxplt_data2,'orientation','horizontal','label',bxplt_lbl,'colors','b','symbol','b+');
> hold on
> p2=boxplot(bxplt_data1,'orientation','horizontal','label',bxplt_lbl,'colors','r','symbol','r+');
> legend([p1,p2],M);
> *****************
> Error:
> ??? Operands to the || and && operators must be convertible to logical
> scalar values.

One issue is that the two boxplot commands each return a matrix of handles
to different parts of the boxes. The legend function isn't expecting you to
pass in a matrix of handles.

You might find it easier to approach this way:

M={'Test A','Test B'};
X1 = randn(30,3);
X2 = 10+randn(30,3);
pos = [(1:size(X1,2)), (1:size(X2,2))];
p1=boxplot([X1 X2],'orientation','horizontal','label',{'#1' '#2' '#3' '' ''
''},...
'symbol','+','pos',pos,'color','rb');
legend(p1(1,[1 2]),M);

-- Tom

Anbazhagan

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Apr 15, 2010, 5:44:04 AM4/15/10

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This appraoch doesnt work either. I get two errors.
First I get an error message saying that 'Incorrect Number of labels'.
My labels have only thirty values. Matlab needs sixty values to plot. So instead of one '#1' label there are two '#1' labels.
I want the two boxplots to share the same labels which is not possible with this approach i guess.

"Tom Lane" <tl...@mathworks.com> wrote in message <hq2a4r$4vj$1...@fred.mathworks.com>...