Accelerating code?

fst-student · September 24, 2015, 09:32

Hello,

I want to accelerate my code.

I have to determine the x-component of a cell center. I know the Cell ID, so I execute this command for every cell I need

Code:

mesh.C()[Cellid].x()

Is this command slow ? Can it be accelerated?
Maybe it is more efficient to determine the required x-coordinates in one command and store them so that I can access the values?

I have several for loop, which loop over all cells. Is there a possibility for exampe to only access the cells where alpha is nonzero? Do I have to generate a list for that or is there a easy way?

Thank you very much.

chriss85 · September 25, 2015, 09:46

First of all, you need to profile your code to figure out which parts of it are slow. In my experience optimizing things like this may give a small boost, but not very much. I would try to avoid reallocating lists all the time and to store the things which can be precalculated. Also try to avoid nested loops if possible.

September 24, 2015, 09:32	Accelerating code?	#1
fst-student New Member Join Date: Jul 2015 Posts: 9 Rep Power: 10	Hello, I want to accelerate my code. I have to determine the x-component of a cell center. I know the Cell ID, so I execute this command for every cell I need Code: mesh.C()[Cellid].x() Is this command slow ? Can it be accelerated? Maybe it is more efficient to determine the required x-coordinates in one command and store them so that I can access the values? I have several for loop, which loop over all cells. Is there a possibility for exampe to only access the cells where alpha is nonzero? Do I have to generate a list for that or is there a easy way? Thank you very much.

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September 25, 2015, 09:46		#2
chriss85 Senior Member Join Date: Oct 2013 Posts: 397 Rep Power: 18	First of all, you need to profile your code to figure out which parts of it are slow. In my experience optimizing things like this may give a small boost, but not very much. I would try to avoid reallocating lists all the time and to store the things which can be precalculated. Also try to avoid nested loops if possible.