Wolfgang Schwanghart

Dear Liu, I can hardly help you here. Do you have sandpile on a search path or in your working direcotry? Please verify that.

Nice one! Works perfectly. Yet I think this function could be made more user-friendly in some ways.

1. Leave the latter two inputs optional such that the function can be called like hp=votebar(high,val);
2. Surpress the output of hp if the function is called without output arguments

Moreover, I found it extremely useful to add some functionality to label the plots. For example it might be great, if a legend could be added to the figure using the function legend.

Yet, all in all this function offers a nice add-on to Matlab's visualization functionality.

To be honest, I am not quite sure what this function is supposed to do different from this statement:
OutPatternMatrix = spones(InPattern).*InMatrix;

Your function help doesn't help much to clarify.
 
Moreover, your function returns an error for following example:
>> InPattern = sprand(5,5,0.4);
>> InMatrix = sprand(5,5,0.4);
>> OutPatternMatrix = sppattern(InPattern,InMatrix)
??? Error using ==> sparse
Vectors must be the same lengths.

Error in ==> sppattern at 30
OutPatternMatrix = sparse(iP,jP,sT,m,n);

Great program Wolfgang, simplicity of use, great code commenting, everything I could have wanted...(and I didnt have to do it myself!)

The error says all: Don't use the function definition in the prompt. Please try following: Type in the command window

help sandpile

than copy the lines in the example and paste them. Does that work?