Scipy error "Inexact indices into sparse matrices are not allowed" when generating RRG

[Karos64]

Hello all,

I know that this repository was last updated like 4 years ago so I'm not expecting a fix for this issue. However I want to highlight it if anybody else will meet the same problem, maybe this issue will be helpful for them to fix it.

I've tried to create a simple Random Regular Graph using following code:

from pygsp import graphs

G = graphs.RandomRegular(N=4, k=2)

And I've got following error:

Traceback (most recent call last):
  File "C:\Users\X\Documents\GitHub\Y\.venv\lib\site-packages\scipy\sparse\_sputils.py", line 359, in isintlike
    operator.index(x)
TypeError: 'numpy.float64' object cannot be interpreted as an integer

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\X\Documents\GitHub\Y\tests\benchmarks.py", line 3, in <module>
    G = graphs.RandomRegular(N=4, k=2)
  File "C:\Users\X\Documents\GitHub\Y\.venv\lib\site-packages\pygsp\graphs\randomregular.py", line 85, in __init__
    if v1 == v2 or A[v1, v2] == 1:
  File "C:\Users\X\Documents\GitHub\Y\.venv\lib\site-packages\scipy\sparse\_lil.py", line 162, in __getitem__
    return IndexMixin.__getitem__(self, key)
  File "C:\Users\X\Documents\GitHub\Y\.venv\lib\site-packages\scipy\sparse\_index.py", line 30, in __getitem__
    index, new_shape = self._validate_indices(key)
  File "C:\Users\X\Documents\GitHub\Y\.venv\lib\site-packages\scipy\sparse\_index.py", line 218, in _validate_indices
    elif isinstance(idx, slice) or isintlike(idx):
  File "C:\Users\X\Documents\GitHub\Y\.venv\lib\site-packages\scipy\sparse\_sputils.py", line 367, in isintlike
    raise ValueError(msg)
ValueError: Inexact indices into sparse matrices are not allowed

I've went and try to figure out what is the cause, I've found that in the following file:

.venv\lib\site-packages\pygsp\graphs\randomregular.py

simply changing lines 81 and 82 from:

v1 = U[i1]
v2 = U[i2]

to

v1 = int(U[i1])
v2 = int(U[i2])

fixes the issue. This might be related to some specific version of numpy/scipy so I'm pasting here what is currently in use in my venv:

$ pip list
Package         Version
--------------- -----------
contourpy       1.3.1
cycler          0.12.1
fonttools       4.55.3
kiwisolver      1.4.8
matplotlib      3.10.0
networkx        3.4.2
numpy           2.2.1
packaging       24.2
pillow          11.1.0
pip             24.3.1
PyGSP           0.5.1
pyparsing       3.2.1
python-dateutil 2.9.0.post0
scipy           1.15.1
setuptools      57.4.0
six             1.17.0

So as I said at the beginning, I don't expect to see fix for this issue, but I'm leaving it here if somebody will ever try to generate RRG using this library ;>

[mdeff]

Fixed by #112.