can the value of rand('seed') be saved

I set random seed value as 0

rand('seed',0);

then i do genetic algorithm using ga

Is there any way i can save the value of rand('seed',0)

so that i can use it without calling rand('seed',0)

Just load it and call function ga

[Guillaume]

Stricly speaking rand('seed', 0) does not have a value. You'll get an error if you try to assign that call to a variable.

It's also important that you understand what it does in modern matlab. It:

• set the generator to 'v4' a random generator that is no longer recommended
• set the seed of that generator to 0.

I think what you're asking is how to save (and restore) the state of the random generator so that any time you use your code it runs exactly the same way.

[Elysi Cochin]

yes sir, thats what i want, "restore the state of the random generator so that any time you use your code it runs exactly the same way in any version of Matlab" Is that possible?

[Walter Roberson]

Yes: you can have your code call rand('seed',0) . Or, for any MATLAB version since R2011a, better is to call rng(0, 'v4')

Answer 1

[Walter Roberson]

"Is there any way i can save the value of rand('seed',0) so that i can use it without calling rand('seed',0) Just load it and call function ga"

Yes. You can create a figure and give it a CreateFcn which executes that command. You can make it 'Visible', 'off' so it does not occupy anything on the screen.

Then save the handle of the figure as part of the .mat file .

When you load the .mat file and so load the figure that is contained inside it, the CreateFcn of the figure will be executed; you would have given it code that sets the random seed for you, so the random seed will be changed.

I do not at all recommend this approach: I would suggest that you instead provide a small function or script that loads your data and sets the random seed, and possibly which also starts ga executing.

Note: rand('seed',value) is considered obsolete. You should be using

rng(0, 'v4')

instead.

[Steven Lord]

From the documentation: "The v4 and v5 generators are no longer recommended unless you are trying to exactly reproduce the random numbers generated in earlier versions of MATLAB."

So rng(0, 'v4') is the correct way to enable the v4 generator IF you need to exactly reproduce random numbers from a very old installation of MATLAB. [There are people reading Answers today who hadn't been born when MATLAB 5.0 was released in December 1996 with the then-new v5 random number generator.]

If you just want reproducible numbers, I recommend rng(n, 'twister') for some fixed value of n instead.