[Numpy-discussion] random seed replicate 2d randn with 1d loop

Keith Goodman kwgoodman at gmail.com
Mon May 23 15:41:55 EDT 2011


On Mon, May 23, 2011 at 12:34 PM,  <josef.pktd at gmail.com> wrote:

> Obviously I was working by columns, using a transpose worked, but
> rewriting to axis=1 instead of axis=0 which should be more efficient
> since I had almost all calculations by columns, I needed
> params = map(lambda x: np.expand_dims(x, 1), params)
> to get around broadcast errors that work automatically with axis=0

Here's another way to work by columns (note the input parameter oder='F'):

>> rs = np.random.RandomState([1,2,3])
>> rs.randn(9).reshape(3,3,order='F')
array([[ 0.89858245, -0.05663392,  0.82495129],
       [ 0.25528877,  0.54721555,  0.17252144],
       [ 0.95172625,  0.11512385,  0.74570118]])
>> rs = np.random.RandomState([1,2,3])
>> rs.randn(3)
   array([ 0.89858245,  0.25528877,  0.95172625])
>> rs.randn(3)
   array([-0.05663392,  0.54721555,  0.11512385])
>> rs.randn(3)
   array([ 0.82495129,  0.17252144,  0.74570118])



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