How to plot error bars

Hello,

Having this type of data....

 time1 = [0.14 0.99 1.67 2.45 3.10 3.70 4.24 5.00]
 res1  = [4 6 2 9 1 0 4 7]
 time2 = [0.11 0.69 1.00 1.45 1.66 2.04 2.24 2.99 3.11 3.43 4.25  
          4.55 5.00]
 res2  = [8 1 5 3 7 1 3  10 9 5  3 2 1] 
 time3 = [0.09 0.33 1.13 1.44 2.10 2.70 3.24 4.00 4.80  5.00]
 res3  = [0 3 4 7 2 6 3 4 9 8]

and a solution (given by Oleg Komarov) to average it....

--------------------------------------------------------

% unique time vector

 untime = 0:0.5:5;
% Idx 
[trash,idx1] = histc(untime,[0 time1(1:end-1) inf]);
[trash,idx2] = histc(untime,[0 time2(1:end-1) inf]);
[trash,idx3] = histc(untime,[0 time3(1:end-1) inf]);
rep = [res1(idx1); res2(idx2); res3(idx3)];
avg = mean(rep);
hold on
% Plot all the lines
stairs(untime,rep.')
% Plot the average in black
stairs([0 untime], [9 avg],'Color','k','Linew',2)

------------------------------------------------------------------

I'd like to know how to plot error bars in this case. I was trying to use function given in matlab but the vectors dimensions don't match.

Thanks for help.

[Oleg Komarov]

Where do you want your error bars, on the middle of the stair or when the stair shifts, i.e. every 0:0.5:5? What kind of error you want? max and min, std error, absolute deviation?

[Marcel]

I'd like to have the error bars(std error) on the middle of the stair.

Answer 1

[Oleg Komarov]

Add this line at the end:

opt = {'k','Linew',2,'LineS','none'};
x   = 0.25:0.5:4.75;
y   = avg(1:end-1);
errorbar(x,y,std(rep(:,1:end-1)),opt{:})

EDIT with min and max

L = y - min(rep(:,1:end-1));
U = max(rep(:,1:end-1)) - y;
errorbar(x,y,L,U,opt{:})

[Marcel]

Thanks very much for your help, really appreciate it.

How would that be with min and max error?

[Marcel]

Thank you Oleg. Great stuff.

Answer 2

[Arturo Moncada-Torres]

I would recommend you to take a look at the following FEX submissions:

• barerrorbar
• create healthy looking error bars
• barerror

[Sean de Wolski]

"healthy error bars" :)

Do healthy error bars finish their vegetables? Is TMW feeding their error bars too much candy?

[Arturo Moncada-Torres]

LOL, good one =)

Answer 3

[ASMS Mat Su]

I have almost similar problem... but this time the value of L and U is on different size. I want it to be L= min and U= max value instead of std error which is only one value (+ or - value).

I tried to create a bar graphs with errorbars(min and min) instead of std error.

Any one know how to solve this?

This is my code and what I tried.

mean = [1 2 3; 4 5 NaN; 7 8 9]; min = [-0.0040 -0.0281 -0.0252; -0.0154 -0.0076 -0.0282; -0.0137 -0.0297 -0.0526]; max = [0.0470 0.0166 0.0015; 0.0015 -0.0038 0.0216; -0.0000 0.0091 0.0316 ];

figure bar(mean); colormap summer grid on hold on

    x = 1:3;
    y = mean;
    L = min;
    U = max;
    errorbar(x,y,L,U);