MATLAB: Multiple runs of normrnd vs. one run of normrnd with several outputs

normrnd normal distribution random

Say that i have a certain mu and sigma
Is normrnd(mu,sigma,1,10) the same as doing normrnd(mu,sigma) 10 times?

Best Answer

Yes. But why not test it yourself?
rng(17)
normrnd(0,1)
ans =
     -0.39509
normrnd(0,1)
ans =
      0.14056
normrnd(0,1)
ans =
      -1.5172
As you can see, these are the first three elements of the next call.
rng(17)
normrnd(0,1,[10,1])
ans =
     -0.39509
      0.14056
      -1.5172
       -1.882
      0.79651
      0.24127
      0.28683
      0.26861
      -2.1682
     -0.15616
normrnd(0,1,[10,1])
ans =
       1.7974
      -1.4667
       0.3709
      0.78102
      -1.3599
      0.34756
     0.084283
      0.23211
    -0.043727
     -0.09342
rng(17)
normrnd(0,1,[10,2])
ans =
     -0.39509       1.7974
      0.14056      -1.4667
      -1.5172       0.3709
       -1.882      0.78102
      0.79651      -1.3599
      0.24127      0.34756
      0.28683     0.084283
      0.26861      0.23211
      -2.1682    -0.043727
     -0.15616     -0.09342
Note that I created them as column vectors so you can see the stream of numbers is indeed the same. Had I created the array as 2x10, the numbers would have been the same, but they would have been stuffed in the array in a different sequence. But this is just a question of how MATLAB stores the elements in an array.
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