How to create a sequence of numbers on the GPU

I want to do the follow in a new GPU Array, efficiently:

myarray = 1:100000

gpuArray(1:100000) works of course, but if I'm not wrong it's creating the large array in main memory then moving the whole thing to the GPU. I would expect that I can create the sequence of numbers on the GPU directly more efficiently, as I can do with many random numbers.

Answer 1

[Edric Ellis]

The direct equivalent is to use gpuArray.colon, like so:

myarray = gpuArray.colon(1,100000);

More here in the doc about building gpuArrays.

[David Parks]

Aha! Didn't see that one, thanks! Looks like it performs nearly the same as linspace, maybe 4ish percent faster.

>> tic; for i = 1:100000; gpuArray.linspace(1,100000,100000); end; toc;
Elapsed time is 9.975085 seconds.
>> tic; for i = 1:100000; gpuArray.colon(1,100000); end; toc;
Elapsed time is 9.486463 seconds.

Doesn't look like I can go back and edit the accepted answer after the fact, drat.

Answer 2

[David Parks]

Found it.

gpuArray.linspace(1,1000,1000);

>> tic; for i = 1:10000; gpuArray(1:100000); end; toc;
Elapsed time is 2.737965 seconds.
>> tic; for i = 1:10000; gpuArray.linspace(1,100000,100000); end; toc;
Elapsed time is 0.916697 seconds.