how to add errorbars

Question

aviran 2014-6-19

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/136433-how-to-add-errorbars

评论： Star Strider 2022-6-6

采纳的回答： Star Strider

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i want to add errorbars to this graph (the error bar are "std_150,std_100 and std_control" in the code).

thanks

the code:

mw_150=[14.5,19,8.5];
mw_100=[10.42,17.4,17.7];
control=[7.15,41.9,44.3];
std_150=[1.16,1.33,0.9];
std_100=[0.83,1.01,1.09];
std_control=[0.71,1.72,1.77];
bar([1 2 3],[mw_150' mw_100' control'])
legend('150mJ/cm2','100mJ/cm2','control');
set(gca, 'FontSize',12,'XTick',[1 2 3 ],'XTickLabel',{'1.5<A.R<2.5','2.5<A.R<3.5','A.R>3.5' });
ylabel('Relative precentage')

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dpb 2014-6-19

Not sure exactly how to envision error "bars" on a bar chart...can you describe what you think it should look like?

Only thoughts come to mind are either use a stacked bar but doesn't really seem like it would work well or use errorbar with the adjust x- coordinates for the bars and no line on the plotted line. I've not tried to see if can convince errorbar to draw the bars but not the trend line directly or whether it would take finding/setting appropriate line handle linestyle property.

aviran 2014-6-19

Fig2_BarChart.png

it should look like in the attached picture

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Answer 1

Star Strider 2014-6-19

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链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/136433-how-to-add-errorbars#answer_141677

编辑：Star Strider 2014-6-19

在 MATLAB Online 中打开

This File Exchange contribution is highly regarded: Bar Chart with Error Bars.

EDIT —

If you’d rather have it look like your attached figure, this code will work:

mw_150=[14.5,19,8.5];
mw_100=[10.42,17.4,17.7];
control=[7.15,41.9,44.3];
std_150=[1.16,1.33,0.9];
std_100=[0.83,1.01,1.09];
std_control=[0.71,1.72,1.77];
hb = bar([1 2 3],[mw_150' mw_100' control'])
legend('150mJ/cm2','100mJ/cm2','control');
set(gca, 'FontSize',12,'XTick',[1 2 3 ],'XTickLabel',{'1.5<A.R<2.5','2.5<A.R<3.5','A.R>3.5' });
ylabel('Relative precentage')
errbar = [std_150; std_100; std_control];   % CREATE ‘errbar’ MATRIX
yd = [mw_150' mw_100' control']';
hold on
for k1 = 1:3
    errorbar([1:3]+.22*(k1-2),  yd(k1,:),  errbar(k1,:), '.k', 'LineWidth',2)
end
hold off

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Star Strider 2014-6-19

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After some outright experimenting, this works:

mw_150=[58,14.5,19,8.5];
mw_100=[54.5,10.42,17.4,17.7];
control=[6.5,7.15,41.9,44.3];
std_150=[2.34,1.16,1.33,0.9];
std_100=[1.9,0.83,1.01,1.09];
std_control=[0.68,0.71,1.72,1.77];
mw_data = [mw_150; mw_100; control];
hb = bar([1 2 3],mw_data)
legend('150mJ/cm2','100mJ/cm2','control');
set(gca, 'FontSize',12,'XTick',[1 2 3 ],'XTickLabel',{'1.5<A.R<2.5','2.5<A.R<3.5','A.R>3.5' });
ylabel('Relative precentage')
errbar = [std_150; std_100; std_control];   % CREATE ‘errbar’ MATRIX
sclf = 0.18;
mv = mean(1:size(mw_data,2));
% sclv = ([1:size(mw_data,2)]-mv)*sclf+1
hold on
for k1 = 1:size(mw_data,1)
    errorbar(([1:4]-mv)*sclf+k1  ,mw_data(k1,:),  errbar(k1,:), '.k', 'LineWidth',2)
end
hold off

If you change anything, it should be robust enough to work except for the variable I call ‘sclf’. That scales the matrix to put the errorbars in the middle of the plotted bars, and I have no idea how MATLAB determines where it puts those bars. The handle graphics don’t say, because all the 'XData' values are the same for all variables. I cannot find anything in the documentation that alludes to where they are stored or how they are calculated. So if you change anything else, experiment with ‘sclf’ until it looks decent.

Yeasir Mohammad Akib 2022-6-6

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Hello State Strider,

Can you please expalin the meaning of this line:

for k1 = 1:size(mw_data,1)
    errorbar(([1:4]-mv)*sclf+k1  ,mw_data(k1,:),  errbar(k1,:), '.k', 'LineWidth',2)
end

The .k portion

Star Strider 2022-6-6

@Yeasir Mohammad Akib — It plots black dots, I believe to avoid connecting the error bars with lines. (This is nearly 8 year-old code. I do not remember what I was thinking back then when I wrote it.)

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Answer 2

dpb 2014-6-19

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/136433-how-to-add-errorbars#answer_141701

编辑：dpb 2014-6-19

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...scales the matrix to put the errorbars in the middle of the plotted bars, and I have no idea how MATLAB determines where it puts those bars. The handle graphics don’t say, because all the 'XData' values are the same for all variables. I cannot find anything in the documentation that alludes to where they are stored or how they are calculated...

Got's to go handle-diving Star--they're not identified per se, but you can compute the location by retrieving the XData property from the barseries object patch...

For the sample above for the first handle, one can find

>> xtik=get(get(hb(1),'children'),'xdata')
xtik =
  0.6545    1.6545    2.6545
  0.6545    1.6545    2.6545
  0.8000    1.8000    2.8000
  0.8000    1.8000    2.8000
>> mean(xtik(1:2:end,:))
ans =
  0.7273    1.7273    2.7273
>>

By comparison, your heuristic values were

>> ([1]-mv)*sclf+[1:3]
ans =
  0.7300    1.7300    2.7300
>>

Not bad... :)

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Star Strider 2014-6-19

Thank you! I went handle-diving, but apparently not deep enough.

dpb 2014-6-19

No problem...came up with this w/ a poster's help when labeling a bar series w/ values. I'd always used a heuristic based on a the 'Width' parameter before but it wasn't completely reliable, either. This returns the real deal of where actually draws the patch object so is dead on...

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