[Bug]: scatter plot fails for list of lists with categorical data #26743

Activity

1. melissawm

   added

   topic: categorical

   topic: plotting methods

   on Sep 12, 2023
2. anntzer commented on Sep 12, 2023

   

   anntzer

   on Sep 12, 2023

   Contributor

   More actions

   FWIW I think we should deprecate the auto-flattening (handling of list-of-lists) in scatter; it is inconsistent e.g. with plot.

   👍React with 👍1Reacted by hannah
3. anirudh-hegde commented on Sep 29, 2023

   

   anirudh-hegde

   on Sep 29, 2023

   More actions

   Bug summary

   scatter plot can handle categorical data and list of lists separately, but cannot handle then both that seems inconsistent. Looks at the examples

   Code for reproduction

   import matplotlib.pyplot as plt
   
   # runs
   plt.scatter([1,2,3], ["a", "b", "a"])
   plt.show()
   
   # runs
   plt.scatter([[1, 0],[ 0, 1]], 
              [[1, 2], [2, 3]])
   plt.show()
   
   # fails
   plt.scatter([[1, 0],[ 0, 1]], 
              [["a", "b"], ["b", "a"]])
   plt.show()

   Actual outcome

   

   
   ValueError Traceback (most recent call last) Cell In[51], line 11 8 plt.show() 10 # fails ---> 11 plt.scatter([[1, 0],[ 0, 1]], 12 [["a", "b"], ["b", "a"]]) 13 plt.show()

   File ~\anaconda3\lib\site-packages\matplotlib\pyplot.py:2862, in scatter(x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, edgecolors, plotnonfinite, data, **kwargs) 2857 @_copy_docstring_and_deprecators(Axes.scatter) 2858 def scatter( 2859 x, y, s=None, c=None, marker=None, cmap=None, norm=None, 2860 vmin=None, vmax=None, alpha=None, linewidths=None, *, 2861 edgecolors=None, plotnonfinite=False, data=None, **kwargs): -> 2862 __ret = gca().scatter( 2863 x, y, s=s, c=c, marker=marker, cmap=cmap, norm=norm, 2864 vmin=vmin, vmax=vmax, alpha=alpha, linewidths=linewidths, 2865 edgecolors=edgecolors, plotnonfinite=plotnonfinite, 2866 **({"data": data} if data is not None else {}), **kwargs) 2867 sci(__ret) 2868 return __ret

   File ~\anaconda3\lib\site-packages\matplotlib__init__.py:1459, in _preprocess_data..inner(ax, data, *args, **kwargs) 1456 @functools.wraps(func) 1457 def inner(ax, *args, data=None, **kwargs): 1458 if data is None: -> 1459 return func(ax, *map(sanitize_sequence, args), **kwargs) 1461 bound = new_sig.bind(ax, *args, **kwargs) 1462 auto_label = (bound.arguments.get(label_namer) 1463 or bound.kwargs.get(label_namer))

   File ~\anaconda3\lib\site-packages\matplotlib\axes_axes.py:4673, in Axes.scatter(self, x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, edgecolors, plotnonfinite, **kwargs) 4667 linewidths = [ 4668 lw if lw is not None else mpl.rcParams['lines.linewidth'] 4669 for lw in linewidths] 4671 offsets = np.ma.column_stack([x, y]) -> 4673 collection = mcoll.PathCollection( 4674 (path,), scales, 4675 facecolors=colors, 4676 edgecolors=edgecolors, 4677 linewidths=linewidths, 4678 offsets=offsets, 4679 offset_transform=kwargs.pop('transform', self.transData), 4680 alpha=alpha, 4681 ) 4682 collection.set_transform(mtransforms.IdentityTransform()) 4683 if colors is None:

   File ~\anaconda3\lib\site-packages\matplotlib\collections.py:994, in PathCollection.init(self, paths, sizes, **kwargs) 980 def init(self, paths, sizes=None, **kwargs): 981 """ 982 Parameters 983 ---------- (...) 991 Forwarded to .Collection. 992 """ --> 994 super().init(**kwargs) 995 self.set_paths(paths) 996 self.set_sizes(sizes)

   File ~\anaconda3\lib\site-packages\matplotlib_api\deprecation.py:454, in make_keyword_only..wrapper(*args, **kwargs) 448 if len(args) > name_idx: 449 warn_deprecated( 450 since, message="Passing the %(name)s %(obj_type)s " 451 "positionally is deprecated since Matplotlib %(since)s; the " 452 "parameter will become keyword-only %(removal)s.", 453 name=name, obj_type=f"parameter of {func.name}()") --> 454 return func(*args, **kwargs)

   File ~\anaconda3\lib\site-packages\matplotlib\collections.py:192, in Collection.init(self, edgecolors, facecolors, linewidths, linestyles, capstyle, joinstyle, antialiaseds, offsets, offset_transform, norm, cmap, pickradius, hatch, urls, zorder, **kwargs) 189 self._joinstyle = None 191 if offsets is not None: --> 192 offsets = np.asanyarray(offsets, float) 193 # Broadcast (2,) -> (1, 2) but nothing else. 194 if offsets.shape == (2,):

   ValueError: could not convert string to float: 'a'

   Expected outcome

   it should provide plot with categorical data on y-axis

   Additional information

   No response

   Operating system

   Windows

   Matplotlib Version

   3.7.1

   Matplotlib Backend

   module://matplotlib_inline.backend_inline

   Python version

   3.10.12

   Jupyter version

   6.5.3

   Installation

   conda

   I am interested to solve your issue