User`s guide

Control Random Number Streams

6-39

For identical results, you can set the client and worker to use the same generator and

seed. Here the file randScript2.m contains the following code:

s = RandStream('CombRecursive','Seed',1);

RandStream.setGlobalStream(s);

R = rand(1,4);

Now, run the new script in the client and on a worker:

randScript2; % In client

R =

0.4957 0.2243 0.2073 0.6823

j = batch(c,'randScript2'); % On worker

wait(j); load(j);

R =

0.4957 0.2243 0.2073 0.6823

Client and GPU

By default MATLAB clients use different random generators than code running on

a GPU. GPUs are more like workers in this regard, and use the Combined Multiple

Recursive generator ('CombRecursive' or 'mrg32k3a') unless otherwise specified.

This example shows a default generation of random numbers comparing CPU and GPU

in a fresh session.

Rc = rand(1,4)

Rc =

0.8147 0.9058 0.1270 0.9134

Rg = rand(1,4,'gpuArray')

Rg =

0.7270 0.4522 0.9387 0.2360

Be aware that the GPU supports only three generators ('CombRecursive',

'Philox4x32-10', and 'Threefry4x64-20'). The following table lists the algorithms

for these generators and their properties.