AttributeError: 'QuadContourSet' object has no attribute 'collections'

[JaimeRZP]

Dear team I think triangle_plot breaks in certain instances when using matplotlib 3.10

Code :

g = plots.getSubplotPlotter(subplot_size=2.5)
g.settings.axes_fontsize = 15
g.settings.legend_fontsize = 15
g.settings.axes_labelsize = 15
g.triangle_plot([samples_3x2_nuisance_nomarg,
                 samples_3x2_nuisance_wzdz_num,
                 samples_3x2_nuisance_wzdz_ana,
                 ],
                 ['Ωm', 'σ8', 'S8'],
                 upper_roots = [samples_3x2_nuisance_nomarg,
                                samples_3x2_nuisance_dz_num,
                                samples_3x2_nuisance_dz_ana,
                                ],
                 upper_kwargs = {'contour_colors':['black', 'C4', 'C2'],
                                'contour_ls': ['--', '-', '-'], 
                                    'filled': [False, True, True],
                                    'contour_lws':4}, 
                line_args=[{'color':'black'},
                           {'color':'C10'},
                           {'color':'C3'}], 
                colors=["black", 'C10', 'C3'],
                param_limits={'Ωm':(0.2, 0.4), 'σ8':(0.65, 0.9), 'S8':(0.67, 0.8)},
                filled=[False, True, True],
                contour_ls=['--', '-', '-'], 
                contour_lws=4,
                legend_ncol=1,
                 markers=prat_markers)
g.export("./paper_plots/triangle_1.pdf")

Error:

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Cell In[23], line 5
      3 g.settings.legend_fontsize = 15
      4 g.settings.axes_labelsize = 15
----> 5 g.triangle_plot([#samples_3x2_nuisance_nomarg,
      6                  samples_3x2_nuisance_wzdz_num,
      7                  samples_3x2_nuisance_wzdz_ana,
      8                  ],
      9                  ['Ωm', 'σ8', 'S8'],
     10                  upper_roots = [samples_3x2_nuisance_nomarg,
     11                                 samples_3x2_nuisance_dz_num,
     12                                 samples_3x2_nuisance_dz_ana,
     13                                 ],
     14                  upper_kwargs = {'contour_colors':['black', 'C4', 'C2'],
     15                                 'contour_ls': ['--', '-', '-'], 
     16                                     'filled': [False, True, True],
     17                                     'contour_lws':4}, 
     18                 line_args=[{'color':'black'},
     19                            {'color':'C10'},
     20                            {'color':'C3'}], 
     21                 colors=["black", 'C10', 'C3'],
     22                 param_limits={'Ωm':(0.2, 0.4), 'σ8':(0.65, 0.9), 'S8':(0.67, 0.8)},
     23                 filled=[False, True, True],
     24                 contour_ls=['--', '-', '-'], 
     25                 contour_lws=4,
     26                 legend_ncol=1,
     27                  markers=prat_markers)
     28 g.export("./paper_plots/triangle_1.pdf")

File ~/anaconda3/envs/gitd/lib/python3.13/site-packages/getdist/plots.py:2573, in GetDistPlotter.triangle_plot(self, roots, params, legend_labels, plot_3d_with_param, filled, shaded, contour_args, contour_colors, contour_ls, contour_lws, line_args, label_order, legend_ncol, legend_loc, title_limit, upper_roots, upper_kwargs, upper_label_right, diag1d_kwargs, markers, marker_args, param_limits, **kwargs)
   2569     self.plot_3d(roots, pair + [col_param], color_bar=False, line_offset=1, add_legend_proxy=False,
   2570                  do_xlabel=i2 == plot_col - 1, do_ylabel=i == 0, contour_args=contour_args,
   2571                  no_label_no_numbers=self.settings.no_triangle_axis_labels, ax=ax, **kwargs)
   2572 else:
-> 2573     self.plot_2d(roots, param_pair=pair, do_xlabel=i2 == plot_col - 1, do_ylabel=i == 0,
   2574                  no_label_no_numbers=self.settings.no_triangle_axis_labels, shaded=shaded,
   2575                  add_legend_proxy=i == 0 and i2 == 1, contour_args=contour_args, ax=ax, **kwargs)
   2576 if marker is not None:
   2577     self._add_marker_list(marker, ax, marker_args)

File ~/anaconda3/envs/gitd/lib/python3.13/site-packages/getdist/plots.py:1736, in GetDistPlotter.plot_2d(self, roots, param1, param2, param_pair, shaded, add_legend_proxy, line_offset, proxy_root_exclude, ax, mask_function, **kwargs)
   1734 contour_args = self._make_contour_args(len(roots), **kwargs)
   1735 for i, root in enumerate(roots):
-> 1736     res = self.add_2d_contours(root, param_pair[0], param_pair[1], line_offset + i, of=len(roots), ax=ax,
   1737                                mask_function=mask_function,
   1738                                add_legend_proxy=add_legend_proxy and root not in proxy_root_exclude,
   1739                                **contour_args[i])
   1740     xbounds, ybounds = self._update_limits(res, xbounds, ybounds)
   1741 if xbounds is not None and 'lims' not in kwargs:

File ~/anaconda3/envs/gitd/lib/python3.13/site-packages/getdist/plots.py:1134, in GetDistPlotter.add_2d_contours(self, root, param1, param2, plotno, of, cols, contour_levels, add_legend_proxy, param_pair, density, alpha, ax, mask_function, **kwargs)
   1132 dashes = args.get('dashes')
   1133 if dashes:
-> 1134     for c in cs.collections:
   1135         c.set_dashes([(0, dashes)])
   1136 if proxy_ix >= 0:

AttributeError: 'QuadContourSet' object has no attribute 'collections'

The error disappears if I downgrade matplotliv to verison 3.9.4

[cmbant]

Does this work?

if dashes:
    cs.set_dashes([(0, dashes)] * len(cs.levels))

[cmbant]

I tried pushing this to master, let me know if it works