random number generation

what do you mean by 'seed' in MATLAB?

Answer 1

[Fangjun Jiang]

If you type help rand or doc rand, it will explain what is seed. I always think of it as the unique ID of a serious of random numbers.

For example, if you run rand(3,1) twice, the results are different.

>> rand(3,1)
ans =
   0.460483750542851
   0.350395373697577
   0.095045735172483
>> rand(3,1)
ans =
   0.433671043922040
   0.709235197729075
   0.115968232562751
>>

But if you specify the seed number, you can duplicate the random number.

>> rand('seed',1);rand(3,1)
ans =
   0.512908935785717
   0.460483750542851
   0.350395373697577
>> rand('seed',1);rand(3,1)
ans =
   0.512908935785717
   0.460483750542851
   0.350395373697577
>>

This is useful sometimes when you try to repeat your test. You need to be able to repeat the inputs even though they are random numbers.