MATLAB: About random number generators

random numbersseed

Hi everyboby

I want to create a program on simulink which use a random number box but I have seen that its output is repeated at each step of the simulation. So how can I change the seed of this program to get the good result.

I use actually matlab 2010a, and I tried rng bgut not working.

Thank you.

Best Answer

As you have found out, using rng is the way to go with the current MATLAB version.

Although currently discouraged, you can use the former synthax for changing the seed with older MATLAB versions: http://www.mathworks.es/es/help/matlab/math/updating-your-random-number-generator-syntax.html

rand('seed', sd)

Related Solutions

MATLAB: How to generate same set of random numbers

You can control random number generation using 'rng()' function. The usage is rng(seed).

rng(seed) seeds the random number generator using the nonnegative integer seed so that rand, randi, and randn produce a predictable sequence of numbers.

Hope that helps..!!

MATLAB: Rand(‘seed’,1)

Seeding the random number generator means initializing it to a certain status. Seeding inside the loop means, that all "random" numbers created inside the loop will be the same in each iteration:

for i = 1:3
  rand('seed', 1);
  disp(rand);
end

Result: 0.51291 0.51291 0.51291

This is not very useful. Seeding RAND outside the loop allows you to reproduce the results:

for j = 1:2
  rand('seed', 1);
  for i = 1:3
    disp(rand);
  end
end

Now you get two series of 3 different numbers:

 0.51291  0.46048  0.3504  0.51291  0.46048  0.3504

Best Answer

Related Solutions

MATLAB: How to generate same set of random numbers

MATLAB: Rand(‘seed’,1)

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