Unexpected behavior of scipy.stats.uniform

Question

Consider the code:

import scipy.stats as ss
x = ss.uniform.rvs(np.zeros(5),np.array([1,2,3,4,5]))

I find the documentation for a scipy.statsbit sparse. From what I can say, I think that the specified code should choose a random number between each of [0,1], [0,2], [0,3], [0,4] and [0,5] . Here is the documentation for rvs and uniform ,

Instead, it selects a random number p in [0,1] and returns [p, 2p, 3p, 4p, 5p]:

print x, np.diff(x)
[ 0.79352054  1.58704108  2.38056162  3.17408215  3.96760269] 
[ 0.79352054  0.79352054  0.79352054  0.79352054]

Is this a seed related error? Or is this behavior expected?

Edit: I know it's easy to get around this; You do not need to tell me how: x=ss.uniform.rvs(size=5)*np.arange(1,5). This error or function cost me a couple of days of confusion and debugging in my larger program.

Answer 1

: https://github.com/scipy/scipy/issues/2069

: size , .

, :

In [1]: import scipy.stats as ss

In [2]: x = ss.uniform.rvs(np.zeros(5), np.array([1,2,3,4,5]))

In [3]: x
Out[3]: array([ 0.23848443,  0.47696885,  0.71545328,  0.9539377 ,  1.19242213])

In [4]: x/x[0]
Out[4]: array([ 1.,  2.,  3.,  4.,  5.])

size=5:

In [18]: x = ss.uniform.rvs(np.zeros(5), np.array([1,2,3,4,5]), size=5)

In [19]: x
Out[19]: array([ 0.67638863,  1.2253443 ,  0.0812362 ,  3.87469514,  3.88145975])

In [20]: x/x[0]
Out[20]: array([ 1.        ,  1.81159802,  0.12010285,  5.72850428,  5.73850534])

Answer 2

, uniform.rvs, *args, size. uniform, rvs, , , .

3 , [0,1], [5,7], [10,13), uniform 0,5,10 1,2,3:

In [543]: u=stats.uniform(np.array([0,5,10]),np.array([1,2,3]))

, 3:

In [544]: x = u.rvs((5,3))
In [545]: x
Out[545]: 
array([[  0.28689704,   6.60720428,  12.78343224],
       [  0.3058824 ,   6.22486472,  11.5212319 ],
       [  0.32274603,   6.72905376,  10.90760859],
       [  0.98299464,   5.39877562,  12.00342556],
       [  0.76728063,   5.26172895,  10.38177301]])
In [546]: x.mean(axis=0)
Out[546]: array([  0.53316015,   6.04432547,  11.51949426])

size stats.uniform.rvs.