[BUG] array must be contiguous

[zxweed]

The error occurs on FORTRAN-style or structured arrays (where data belonging to one series do not reside in memory continuously)

Reproducing the bug :mag:

import numpy as np
from plotly_resampler import FigureResampler

x = np.arange(1_000_000)
y = np.zeros(shape=(2, k), order='F')
y[0] = (3 + np.sin(x / 200) + np.random.randn(len(x)) / 10) * x / 1_000

fig = FigureResampler(go.Figure())
fig.add_trace(go.Scattergl(name='noisy sine', showlegend=True), hf_x=x, hf_y=y[0])

Error message:

File ~/micromamba/lib/python3.11/site-packages/tsdownsample/downsampling_interface.py:376, in AbstractRustDownsampler.downsample(self, n_out, parallel, *args, **kwargs)
    368 def downsample(self, *args, n_out: int, parallel: bool = False, **kwargs):
    369     """Downsample the data in x and y.
    370 
    371     The x and y arguments are positional-only arguments. If only one argument is
   (...)
    374     considered to be the y-data.
    375     """
--> 376     return super().downsample(*args, n_out=n_out, parallel=parallel, **kwargs)

File ~/micromamba/lib/python3.11/site-packages/tsdownsample/downsampling_interface.py:131, in AbstractDownsampler.downsample(self, n_out, *args, **kwargs)
    129 x, y = self._check_valid_downsample_args(*args)
    130 self._supports_dtype(y, y=True)
--> 131 self._check_contiguous(y, y=True)
    132 if x is not None:
    133     self._supports_dtype(x, y=False)

File ~/micromamba/lib/python3.11/site-packages/tsdownsample/downsampling_interface.py:38, in AbstractDownsampler._check_contiguous(self, arr, y)
     35 if arr.flags["C_CONTIGUOUS"]:
     36     return
---> 38 raise ValueError(f"{'y' if y else 'x'} array must be contiguous.")

ValueError: y array must be contiguous.

Environment information:

• OS: linux
• Python environment:
  • Python 3.8+:
  • plotly-resampler environment: Jupyter(lab)
• plotly-resampler version: 0.10.0

Additional context It looks like the downsampler can only process strictly contiguous data. It would be good to either make it work with strides or call np.ascontiguousarray after check the C_CONTIGUOUS flag.