Test code:

from sklearn.datasets import load_digits
from gtda.homology import CubicalPersistence
from gtda.diagrams import PairwiseDistance

X, _ = load_digits(return_X_y=True) 
nb_samples = 100
CP = CubicalPersistence(homology_dimensions=(0, 1))
X_diag = CP.fit_transform(X[:nb_samples].reshape(nb_samples, 8, 8))
PD = PairwiseDistance(
    metric='bottleneck', metric_params={'delta'

Since 2.3 and commit 1b5a9b239acf83ed278db263ecb23bd0af43e39d, we may get this error when OpenCL is disabled.

OpenCL: Failed to get number of platforms with clGetPlatformIDs(): -1001

From CL/cl_ext.h:

/* Additional Error Codes                                                  */
#define CL_PLATFORM_NOT_FOUND_KHR                   -1001

It looks it occurs when generic Open

It could be useful to have a way to clone a simplex tree, more efficiently than a loop on get_filtration doing inserts (we have a copy constructor in C++).