randperm not working correctly on Matlab Web App

Hello everyone,

I have a problem with the randperm function. In the MATLAB App designer it always outputs a random number, but in the Web App the numbers are always the same. Is that the expected behavior? May I be missing something?

[Cris LaPierre]

Do you set the rng seed before calling randperm?

[Marcos]

No, I haven't! Should I use the rng seed function with a specific parameter?

[Cris LaPierre]

No, but if you are using it, it will cause the same random numbers to be generated each time.

Answer 1

[Steven Lord]

I believe that each instance of the Web App is or is equivalent to a new session of MATLAB. In that case this documentation page applies. Follow the instructions it gives to generate random numbers that are different each time.

[Marcos]

Yes, actually I have managed to solve the problem using rng('shuffle') before each call of randperm. I think that the problem was with how the server manages the sessions.

Thank you all for your replies!