fix IndexError in FPCAPlot

[Quentin62]

FPCAplot returns an IndexError when the number of components to plot is not equal to the number of created axes.

In the following, I plot 3 components, FPCAplot has created a 2*2 subplots and can not allocate a plot for the last axe and throws an IndexError

import matplotlib.pyplot as plt
from skfda.datasets import fetch_weather
from skfda.exploratory.visualization import FPCAPlot
from skfda.preprocessing.dim_reduction.feature_extraction import FPCA
from skfda.representation.grid import FDataGrid
from skfda.representation.basis import BSpline

# create a FDataGrid with temperature from CanadianWeather
dataset = fetch_weather()
data_temp = FDataGrid(data_matrix=dataset["data"].data_matrix[:, :, 0], grid_points=dataset["data"].grid_points)

# basis expansion
basis_10 = BSpline(domain_range=data_temp.domain_range, n_basis=10, order=4)
temp_fd  = data_temp.to_basis(basis_10)

# fpca
fpca = FPCA(n_components=3)
fpca.fit(temp_fd)

FPCAPlot(temp_fd.mean(), fpca.components_, factor=100).plot()

---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
Cell In[38], line 1
----> 1 FPCAPlot(temp_smooth_10.mean(), fpca.components_, factor=100).plot()

File [~/.local/lib/python3.10/site-packages/skfda/exploratory/visualization/_baseplot.py:98](https://file+.vscode-resource.vscode-cdn.net/home/quentin/Documents/Pr%C3%A9sentation/fda/~/.local/lib/python3.10/site-packages/skfda/exploratory/visualization/_baseplot.py:98), in BasePlot.plot(self)
     95 if self.y_label is not None:
     96     axes[0].set_ylabel(self.y_label)
---> 98 self._plot(fig, axes)
    100 self._hover_event_id = fig.canvas.mpl_connect(
    101     'motion_notify_event',
    102     self.hover,
    103 )
    105 return fig

File [~/.local/lib/python3.10/site-packages/skfda/exploratory/visualization/fpca.py:87](https://file+.vscode-resource.vscode-cdn.net/home/quentin/Documents/Pr%C3%A9sentation/fda/~/.local/lib/python3.10/site-packages/skfda/exploratory/visualization/fpca.py:87), in FPCAPlot._plot(self, fig, axes)
     84     self.mean = self.mean.mean()
     86 for i, ax in enumerate(axes):
---> 87     perturbations = self._get_component_perturbations(i)
     88     GraphPlot(fdata=perturbations, axes=ax).plot()
     89     ax.set_title(f"Principal component {i + 1}")

File [~/.local/lib/python3.10/site-packages/skfda/exploratory/visualization/fpca.py:107](https://file+.vscode-resource.vscode-cdn.net/home/quentin/Documents/Pr%C3%A9sentation/fda/~/.local/lib/python3.10/site-packages/skfda/exploratory/visualization/fpca.py:107), in FPCAPlot._get_component_perturbations(self, index)
    104     raise AttributeError("X must be a FData object")
    105 perturbations = self.mean.copy()
...
--> 572         raise IndexError("index out of bounds")
    574     return slice(key, key + 1)
    576 return key

IndexError: index out of bounds

I add an if statement in the loop to compare the current enumerate value with the number of plots

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: -0.01 ⚠️

Comparison is base (48fb0ad) 85.86% compared to head (4a56dd7) 85.85%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #554      +/-   ##
===========================================
- Coverage    85.86%   85.85%   -0.01%     
===========================================
  Files          147      147              
  Lines        11649    11650       +1     
===========================================
  Hits         10002    10002              
- Misses        1647     1648       +1     

Impacted Files	Coverage Δ
skfda/exploratory/visualization/fpca.py	42.10% <0.00%> (-1.14%)	⬇️

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[vnmabus]

Thank you for the fix! I should probably do a refactor of the visualization code in the future, as it is a bit messy right now.