stdshade

Short code to create shading around a mean. Input is a matrix with rows of observations.

Description

usage: stdshade(amatrix,alpha,acolor,F,smth)
plot mean and standard deviations(std) coming from a matrix of data, at which each row is an observation. std can be changed to standard error of the mean(sem) in the code. sem/std is shown as shading.

- acolor defines the used color (default is red)
- F assignes the used x axis (default is steps of 1).
- alpha defines transparency of the shading (default is no shading and black mean line)
- smth defines the smoothing factor (default is no smooth)

• MATLAB release: MATLAB 7.5 (R2007b)

[Jeff Tuhtan]

Useful file, but a few changes can be made, as it did not work at the onset:

if exist('F','var')==0 || isempty(F);
    F=1:size(amatrix,1);
end

The above code had returned the size of the columns.

and

amean=smooth(amatrix,smth)';

The above code had used nanmean, which calculated the mean of the whole dataset, resulting in only a point being plotted.

[Simon Musall]

Thanks for your suggestions.

I'm not quit sure if I understand your changes though. When you change the size to the fir dimension, it gives you the amount of observations instead of their actual length. When I try to change it that way, the code breaks as F and the mean of observations has not the same length anymore.

Have you tried using amatrix' as an input instead? Maybe you are using a different matrix structure as I do.

[Thorsten Bartels-Rausch]

Hi...thanks, works great, looks great!
except: On Mac (and Linux) the axes vanish once the shaded areas are introduced. (This seems to be connected with the OpenGL renderer that is used for alpha values below 1). A work around is to change the view-angle just a little by adding this line somewhere after stdshade is called:
camva(gca,camva+(camva/1000))

[Simon Musall]

Hi Thorsten,

thanks for your suggestion. Apparently, the axis can also vanish under Win7. I think, the reason for this is the stretch-to-fill behavior (which is also disabled when changing the view-angle). I thought about adding this fix into the code but unfortunately it creates new problems e.g. when doing subplots. If someone has the axis problem, it therefore seems to make most sense to find a individual solution which produces a figure that fits the needs best. I found it useful to change the axis aspect ratio to disable stretch to fill:

http://www.mathworks.com/help/techdoc/visualize/f4-24991.html