McClean: Making Nice Bar Plots: Difference between revisions
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This is ok, but we'd rather only have one-sided error bars. To do this, you will send barwitherr zeros for the lower error and keep the upper error as is by sending in the matrix cat(3,zeros(4,2),[Strain1_std' Strain2_std']) for the error | This is ok, but we'd rather only have one-sided error bars. To do this, you will send barwitherr zeros for the lower error and keep the upper error as is by sending in the matrix cat(3,zeros(4,2),[Strain1_std' Strain2_std']) for the error | ||
< | <pre> | ||
barwitherr(cat(3,zeros(4,2),[Strain1_std' Strain2_std']), [1 2 3 4],[Strain1_Mean' Strain2_Mean']) | barwitherr(cat(3,zeros(4,2),[Strain1_std' Strain2_std']), [1 2 3 4],[Strain1_Mean' Strain2_Mean']) | ||
legend('Strain 1','Strain 2') | legend('Strain 1','Strain 2') | ||
pause; close all; | pause; close all; | ||
</ | </pre> | ||
[[Image:Fig3_BarChartEx.png]] | |||
%Now let's use better colors by changing the color map and set the bar widths, line widths, axis fonts etc to something prettier | |||
<pre> | |||
barwitherr(cat(3,zeros(4,2),[Strain1_std' Strain2_std']), [1 2 3 4],[Strain1_Mean' Strain2_Mean'],'LineWidth',2,'BarWidth',0.9) | |||
legend('Strain 1','Strain 2') | |||
</pre> | |||
set the axis properties | |||
<pre> | |||
ax=gca; | |||
set(ax, 'FontSize',12) | |||
</pre> | |||
[[Image:Fig4_BarChartEx.png]] | [[Image:Fig4_BarChartEx.png]] | ||
[[Image:Fig5_BarChartEx.png]] | [[Image:Fig5_BarChartEx.png]] |
Revision as of 15:42, 8 June 2012
Summary
This explains the basics of making pretty bar plots in Matlab. The Matlab "bar" command is used, along with some nice scripts discovered on the Matlab file exchange.
Example
Suppose you have some experimental data from two strains (Strain 1 and Strain 2) under four different experiment conditions (Condition A,B,C,D). The means and standard deviations of your measurement of interest look like:
Strain1_Mean=[0.5137 3.2830 1.5887 5.9188]; Strain2_Mean=[0.4042 2.9884 0.5709 2.7766]; Strain1_std=[1.1393 2.8108 2.2203 3.5233]; Strain2_std=[0.8762 2.8478 0.9878 2.2197];
Use Matlab's bar command to plot this data (without error bars) as a bar chart:
bar([1 2 3 4],[Strain1_Mean' Strain2_Mean']) legend('Strain 1','Strain 2') pause; close all;
This looks ok, but we would really like some error bars, so we use a handy function from the file exchange:
h=figure; hold; barwitherr([Strain1_std' Strain2_std'], [1 2 3 4],[Strain1_Mean' Strain2_Mean']) legend('Strain 1','Strain 2') pause; close all;
This is ok, but we'd rather only have one-sided error bars. To do this, you will send barwitherr zeros for the lower error and keep the upper error as is by sending in the matrix cat(3,zeros(4,2),[Strain1_std' Strain2_std']) for the error
barwitherr(cat(3,zeros(4,2),[Strain1_std' Strain2_std']), [1 2 3 4],[Strain1_Mean' Strain2_Mean']) legend('Strain 1','Strain 2') pause; close all;
%Now let's use better colors by changing the color map and set the bar widths, line widths, axis fonts etc to something prettier
barwitherr(cat(3,zeros(4,2),[Strain1_std' Strain2_std']), [1 2 3 4],[Strain1_Mean' Strain2_Mean'],'LineWidth',2,'BarWidth',0.9) legend('Strain 1','Strain 2')
set the axis properties
ax=gca; set(ax, 'FontSize',12)
Example 2: Plotting one errorbar plot and a non-errorbar plot on the same x-axis with different y axis
M1=randn(100,10); x=linspace(1,10,10); y=2*x; [a,h1,h2]=plotyy(x,M1,x,y,'EBplotyy','plot') set(get(a(1),'YLabel'),'String','Errorbar Plot') set(get(a(2),'YLabel'),'String','Some Other Plot') title('Errorbar Plot and some other Random Plot') set(get(a(1),'XLabel'),'String','Points')
Code
function h=EBplotyy(x,y) %INPUT: %x-independent variable (often Time) %y-dependent variable %OUTPUT: %h-handle of the errorbar graphics object % %Save this code in an m-file named EBplotyy.m s=nanstd(y); h=errorbar(x,nanmedian(y),nanstd(y)); %NOTE: You might want to change nanmedian to nanmean, nanstd to standard error, etc depending on what you want to plot
Notes
Please feel free to post comments, questions, or improvements to this protocol. Happy to have your input!
- Megan N McClean 17:27, 30 January 2012 (EDT): Obviously this is nothing fancy, but the code has come in handy for me a number of times, so I thought I would stick it on the wiki in case it is useful to anyone else in the lab.
References
Mathworks Online Help: plotyy
Matlab Newsreader: Plotyy with errorbar
Contact
- Megan N McClean 14:01, 30 January 2012 (EDT)
or instead, discuss this protocol.