parfor and rng(1)

Hi there,

I was doing matlab simulation based on different SNR and rng, and want to use parfor to speed up, can we do like this?(can we use rng together with parfor?)

rng(1)

count=10000;

for SNR=20:5:50

for i = 1: count

chan_coef = randn(1,1)+1i*randn(1,1);

...

end

end

%Is It Correct to Change to

rng(1)

count=10000;

parfor SNR=20:5:50

parfor i = 1: count

chan_coef = randn(1,1)+1i*randn(1,1);

...

end

end

Thanks,

Charlie

[mingcheng nie]

thank you for your comments!

Answer 1

[Bruno Luong]

rdn(1) outside the parfor has no effect.

from the doc:

"For independent streams on the workers, use the default behavior or consider using a unique substream on each worker using RandStream."

So you should leave the parfor loop alone or use RandSteam inside parfor loop (but not rdn('shuffle') as warned the doc).