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stacked histogram and xaxis issues

Yasmin Samy さんによって質問されました 2018 年 5 月 22 日
最新アクティビティ Yasmin Samy さんによって コメントされました 2018 年 5 月 24 日
Hello, I`m plotting histograms and would like stack 2 data sets instead of having them overlap. The problem is i didn`t find any options for histograms to do that in Matlab. It seems you need to use bar, but then i get the issue of the xaxis ticks and labels. Does anyone know how to properly plot stacked histograms?
For bar plots, how do we set the xaxis ticks and labels? (i tried set(gca....) and d.Xtick...and it didn`t work.
thanks

  3 件のコメント

dpb
2018 年 5 月 23 日
What, specifically, do you mean by "stacked histogram"? Can you show an image of what you think should look like or point to a link of a sample?
OCDER
2018 年 5 月 23 日
Is the stacked bar graph what you're looking for?
%Example from MathWorks website:
y = [2 2 3; 2 5 6; 2 8 9; 2 11 12];
bar(y,'stacked')
Yasmin Samy 2018 年 5 月 23 日
yes that's what i mean. similar to the stacked bar plots. but i wanted to do it using histogram function where you have the edges on the xaxis. The bar plot just puts a count from 1 to N on the xaxis and i can't seem to replace that.

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1 件の回答

回答者: Benjamin Kraus 2018 年 5 月 23 日
 採用された回答

In order to use the bar command to plot a histogram, you need to specify the X-values when you call the bar command. For example:
[N1,edges] = histcounts(randn(1000,1));
N2 = histcounts(randn(1000,1),edges); % Bin using the same edges
ctrs = (edges(1:end-1)+edges(2:end))/2; % Calculate the bin centers
bar(ctrs, [N1' N2'],1,'stacked','FaceAlpha',0.6);
Once that is done, you can either set the ticks to auto, or to the specific bin edges:
xticks auto % Use automatic ticks
xticks(edges) % Use specific edges

  6 件のコメント

Yasmin Samy 2018 年 5 月 24 日
It seems in matlab R2016a xticks isn't used like this. Usually its axis.XTick= or set(gca,'Xtick') but for some reason im still not getting the results i want.
regarding this line: bar(ctrs, [N1' N2'],1,'stacked','FaceAlpha',0.6); what is the "1" before stacked referring to?
dpb
2018 年 5 月 24 日
Indeed xticks was introduced in 16b
>> help bar
bar Bar graph.
...
bar(X,Y,WIDTH) or bar(Y,WIDTH) specifies the width of the bars. Values
of WIDTH > 1, produce overlapped bars. The default value is WIDTH=0.8
...
The doc version uses
...
bar(_____,width)
...
which leaves more to imagination, but the underscore implies the all previous explicit arguments prior to that; iow x,y
Show us what you got; explain specifically what isn't what you want and what that is...
ADDENDUM
Taking a guess, try
hAx=gca; % get handle
xlim([-4.5 4.5]) % symmetrize range
hAx.XAxis.TickLabelFormat='%0.1f'; % consistent format
hAx.XAxis.FontSize=9; % get a little more room
hAx.XTick=edges; % put ticks at bin edges
Probably still won't be sufficient room unless spread figure out wider to clearly read the tick values; you'll have to decide what's more important to show...
Yasmin Samy 2018 年 5 月 24 日
Thanks for your help so far.
So just to recap, i tried the following code templates and they successfully worked this time!
ctrs = (edges(1:end-1)+edges(2:end))/2; % Calculate the bin centers bar(ctrs, [N1' N2'],1,'stacked','FaceAlpha',0.6);
suggested by Benjamin at first, and it worked well so far. I removed the xlim and Xlabel lines where i was trying to adjust my xaxis but they were just messing it up more!
Also i had a log scale, with which using xlim helped solve the issue of an axis that was repeating itself(0.001 0.01 0.1 1 0.001 0.01 0.1 1).
Thanks for your patience and support!!

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