Prev: Remember the Consolidator by John D'Errico?
Next: Angle between two vectors
From: Arvind Raghavan on 16 Jun 2010 19:33
Here is the profiling output of a class method:

time calls line

< Earlier lines deleted>
0.59 104502 138 numGiven = self.localState(idx).numGiven;
341.96 104502 139 numNeeded = self.globalState{idx}.process(procId).numNeeded;
2.06 104502 140 if self.localState(idx).isValid && numNeeded == numGiven
<Rest of the lines deleted>

A harmless looking assignment in the second line above seems to be taking a disproportionately large amount of time to execute per the profiler. Note that self.globalState is a cell array. The only other piece of information that may be useful is that the self.globalState property copied into this object during construction and is read-only-- it is never modified in the code for this class, while self.localState loacally generated and is modified. There are other instances too where the profiler shows that anytime a variable is assigned from globalState, it takes much longer than expected.

Is accessing elements of a cell array so expensive? Or is copy-on-write somehow working like copy-on-access?

Thanks for any help you can provide,

Arvind
 | 
Pages: 1
Prev: Remember the Consolidator by John D'Errico?
Next: Angle between two vectors