Error reporting for dist matrix

[bdpedigo]

Error reporting for distance matrix input is unclear.

There are 2 problems here: 1) is that sklearn pairwise_distances returns something where the diagonals are not exactly 0 when you pass in a pandas dataframe of floats, which is obviously not your problem. 2) is that the error message says dimension mismatch when it shouldn't (should report trace is not 0 in one of the distance matrices).

However, wondering if it also makes sense to change these to be soft checks (close to 0 as opposed to exactly 0). I don't have a strong feeling about that either way.

Reproducing code example:

import numpy as np
import pandas as pd
from sklearn.metrics import pairwise_distances

X = np.random.uniform(size=(100, 2))
Y = np.random.normal(size=(100, 2))
X = pd.DataFrame(X)
X_dist = pairwise_distances(X)
Y_dist = pairwise_distances(Y)
print(np.diag(X_dist).max())
MGC(None).test(X_dist, Y_dist)

Error message

2.1073424255447017e-08
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
/mnt/c/Users/t-bpedig/code/graph-embedding-methods/GraphEmbeddingMethods/sandbox/notebooks/2020-06-29-v2-maggot-hemisphere-single-embed.py in 
      163 Y_dist = pairwise_distances(Y)
     164 print(np.diag(X_dist).max())
---> 165 MGC(None).test(X_dist, Y_dist)

~/miniconda3/envs/embed/lib/python3.7/site-packages/hyppo/independence/mgc.py in test(self, x, y, reps, workers)
    217 
    218         if self.is_distance:
--> 219             check_xy_distmat(x, y)
    220 
    221         # using our joblib implementation instead of multiprocessing backend in

~/miniconda3/envs/embed/lib/python3.7/site-packages/hyppo/_utils.py in check_xy_distmat(x, y)
     80     if nx != px or ny != py or np.trace(x) != 0 or np.trace(y) != 0:
     81         raise ValueError(
---> 82             "Shape mismatch, x and y must be distance matrices "
     83             "have shape [n, n] and [n, n]."
     84         )

ValueError: Shape mismatch, x and y must be distance matrices have shape [n, n] and [n, n].

Version information

• OS: Ubuntu 20.04
• Python Version 3.7.3
• Package Version 0.1.2