Accumulate Connected Components

Construct array with accumulation of connected components

Description

accumconncomps creates vectors by accumulating elements in one vector using the connected components in another vector of same size. Connected components are regarded as subsequent, identical elements in a vector.

Example:
Sum the values in val according to the connected components in cc.
 
cc = [1 1 2 1 1 1 3 3 3 4 2 2];
val = [2.3 1.2 5 3 2 5 3.2 4.5 2 ...
       2.2 1.2 2.2];
  
[c,valnew] = accumconncomps(cc,val,@sum)
  
c = 1 2 1 3 4 2
valnew = 3.5 5.0 10.0 9.7 2.2 3.4

I know, the function is rather simple, but needed it several times and perhaps others do so as well. In case you have a better way to code it, or in case you have any suggestion for an improved help text, please let me know.

• MATLAB release: MATLAB 7.5 (R2007b)