Closed
Description
Dirichlet.random appears to have some shape issues.
import numpy as np
import pymc3 as pm
dir_dist = pm.Dirichlet.dist(np.r_[1, 1])
dir_dist.random()[[0.47011506 0.52988494]
[0.38131591 0.61868409]]The output has too many dimensions.
Specifying size=1 only adds another dimension:
dir_dist.random(size=1)[[[0.46690176 0.53309824]
[0.01646167 0.98353833]]]The output starts to look correct around here:
dir_dist.random(size=2)[[0.18456125 0.81543875]
[0.26424679 0.73575321]]Larger values of size aren't any better:
dir_dist.random(size=3)[[[0.46520733 0.53479267]
[0.44132648 0.55867352]]
[[0.69477003 0.30522997]
[0.3173439 0.6826561 ]]
[[0.82510178 0.17489822]
[0.98854784 0.01145216]]]If we set the shape explicitly, things seem to improve in the size=None case:
dir_dist = pm.Dirichlet.dist(np.r_[1, 1], shape=2)
dir_dist.random()[0.01529536 0.98470464]Unfortunately, things get weird when size == 2.
dir_dist.random(size=2)[1. 1.]Versions and main components
- PyMC3 Version: 049187f
- Theano Version: 1.0.4
- Python Version: 3.6.4
- Operating system: Ubuntu 20.04
- How did you install PyMC3: pip