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Wrong results with hypergeom cdf

See original GitHub issue

The hypergeometric cdf gives wrong results with invalid parameters

Reproducing code example:

import numpy as np 
import scipy.stats as st 

print(st.hypergeom(M=3, n=3, N=4).pmf(np.arange(5))) 
print(st.hypergeom(M=3, n=3, N=4).cdf(np.arange(5)))

[nan nan nan nan nan]
[nan nan nan  1.  1.]

Scipy/Numpy/Python version information:

scipy = 1.5.4
numpy = 1.19.4
sys.version_info(major=3, minor=8, micro=5, releaselevel='final', serial=0)

Issue Analytics

State:
Created 3 years ago
Comments:5 (5 by maintainers)

Top GitHub Comments

1reaction

WarrenWeckessercommented, Dec 22, 2020

I think a separate PR would be better.

1reaction

WarrenWeckessercommented, Dec 22, 2020

@tirthasheshpatel, that doesn’t look right. The same problem occurs with the public method support:

n [2]: hypergeom.support(1, 3, 4)
Out[2]: (6, 3)

I suspect a call to _argcheck needs to be incorporated into the support method of the rv_generic class.

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