@@ -753,6 +753,151 @@ def text(self, x, y, s, fontdict=None, **kwargs):
753753 self ._add_text (t )
754754 return t
755755
756+ def label_lines (self , * args , ** kwargs ):
757+ handles , labels , extra_args , kwargs = mlegend ._parse_legend_args (
758+ [self ],
759+ * args ,
760+ ** kwargs )
761+ if len (extra_args ):
762+ raise TypeError (
763+ 'label_lines only accepts two nonkeyword arguments' )
764+
765+ self ._line_labels = []
766+
767+ # TODO(omarchehab98): Should we avoid using a Line2D method from inside
768+ # the Axes class?
769+ # If it's okay, we should check if handle is an
770+ # instance of Line2D.
771+ def get_last_data (handle ):
772+ last_x = handle .get_xdata ()[- 1 ]
773+ last_y = handle .get_ydata ()[- 1 ]
774+ return last_x , last_y
775+ # Get last data point for each handle
776+ xys = list (map (get_last_data , handles ))
777+
778+ # Find the largest last x value
779+ data_maxx = max (map (lambda point : point [0 ], xys ))
780+ # TODO(omarchehab98): We do eventually sort `xys` by `y`.
781+ # If we reorder things we can do these two
782+ # computations in constant time.
783+ # Rather than linear time.
784+ # Find the smallest last y value
785+ data_miny = min (map (lambda point : point [1 ], xys ))
786+ # Find the largest last y value
787+ data_maxy = max (map (lambda point : point [1 ], xys ))
788+
789+ # Get the figure width and height in pixels
790+ fig_dpi_transform = self .figure .dpi_scale_trans .inverted ()
791+ fig_bbox = self .get_window_extent ().transformed (fig_dpi_transform )
792+ fig_width_px = fig_bbox .width * self .figure .dpi
793+ fig_height_px = fig_bbox .height * self .figure .dpi
794+
795+ # Get the figure width and height in points
796+ fig_minx , fig_maxx = self .get_xbound ()
797+ fig_miny , fig_maxy = self .get_ybound ()
798+ fig_width_pt = abs (fig_maxx - fig_minx )
799+ fig_height_pt = abs (fig_maxy - fig_miny )
800+
801+ # Space to the left of the text converted from pixels
802+ margin_left = 8 * (fig_width_pt / fig_width_px )
803+ # Space to the top and bottom of the text converted from pixels
804+ margin_vertical = 2 * (fig_height_pt / fig_height_px )
805+
806+ text_fontsize = 10
807+ # Height of the text converted from pixels
808+ text_height = text_fontsize * (fig_height_pt / fig_height_px )
809+
810+ # Height of each bucket
811+ bucket_height = text_height + 2 * margin_vertical
812+ # Total number of buckets
813+ buckets_total = 2 * int ((fig_maxy - fig_miny - text_height ) /
814+ bucket_height )
815+ # Bit array to track which buckets are used
816+ buckets_map = 0
817+
818+ def get_bucket_index (y ):
819+ return int ((y - fig_miny ) / bucket_height )
820+
821+ # How many text SHOULD be in this bucket
822+ bucket_densities = [0 ] * buckets_total
823+ for xy in xys :
824+ data_x , data_y = xy
825+ bucket = get_bucket_index (data_y )
826+ bucket_densities [bucket ] += 1
827+
828+ def by_y (args ):
829+ xy = args [2 ]
830+ x , y = xy
831+ return y
832+
833+ bucket_offset = None
834+ prev_ideal_bucket = - 1
835+ # Iterate over all the handles, labels, and xy data sorted by y asc
836+ for handle , label , xy in sorted (zip (handles , labels , xys ), key = by_y ):
837+ data_x , data_y = xy
838+
839+ ideal_bucket = get_bucket_index (data_y )
840+ if ideal_bucket != prev_ideal_bucket :
841+ # If a bucket is dense, then we want to center the text around
842+ # the bucket. SSo, find out how many empty buckets there are
843+ # below the current bucket
844+ bucket_density = bucket_densities [ideal_bucket ]
845+ ideal_offset = bucket_density // 2
846+ empty_buckets_below = 0
847+ for i in range (ideal_bucket + 1 ,
848+ ideal_bucket - ideal_offset + 1 ,
849+ - 1 ):
850+ # If reached bottom or bucket is not empty
851+ if i == 0 or buckets_map & (1 << i ) == 1 :
852+ break
853+ empty_buckets_below += 1
854+ bucket_offset = - min (ideal_offset , empty_buckets_below )
855+ prev_ideal_bucket = ideal_bucket
856+
857+ bucket = ideal_bucket + bucket_offset
858+ text_x , text_y = None , None
859+
860+ # Find the nearest empty bucket
861+ for index in range (buckets_total ):
862+ # 0 <= bucket_index <= buckets_total
863+ bucket_index = max (0 , min (bucket + index , buckets_total ))
864+ bucket_mask = 1 << bucket_index
865+ # If this bucket is empty
866+ if buckets_map & bucket_mask == 0 :
867+ # Mark this bucket as used
868+ buckets_map |= bucket_mask
869+ text_x = data_maxx + margin_left
870+ text_y = bucket_index * bucket_height + fig_miny
871+ break
872+
873+ # If a bucket was found for the text
874+ if text_x is not None and text_y is not None :
875+ text_color = handle .get_color ()
876+ line_label = self .annotate (label , (data_maxx , data_y ),
877+ xytext = (text_x , text_y ),
878+ fontsize = text_fontsize ,
879+ color = text_color ,
880+ annotation_clip = True )
881+ self ._line_labels .append (line_label )
882+
883+ # A bucket is not necessarily aligned with the data point
884+ # If space allows, center the text around the data point
885+ for line_label in self ._line_labels :
886+ datax , datay = line_label .xy
887+ targety = datay - text_height / 2
888+ textx , texty = line_label .get_position ()
889+ direction = 1 if targety > texty else - 1
890+ bucket_mask = 1 << (get_bucket_index (targety ) + direction )
891+ if (get_bucket_index (targety ) == get_bucket_index (texty ) and
892+ buckets_map & bucket_mask == 0 ):
893+ line_label .set_position ((textx , targety ))
894+
895+ def reset_label_lines (self , * args , ** kwargs ):
896+ for label in self ._line_labels :
897+ label .remove ()
898+ self ._line_labels = []
899+ self .label_lines (* args , ** kwargs )
900+
756901 @cbook ._rename_parameter ("3.3" , "s" , "text" )
757902 @docstring .dedent_interpd
758903 def annotate (self , text , xy , * args , ** kwargs ):
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