@@ -662,6 +662,29 @@ class Ticker(object):
662662formatter = None
663663
664664
665+ class _LazyTickList (object ):
666+ """
667+ A descriptor for lazy instantiation of tick lists.
668+
669+ See comment above definition of the ``majorTicks`` and ``minorTicks``
670+ attributes.
671+ """
672+
673+ def __init__ (self ,major ):
674+ self ._major = major
675+
676+ def __get__ (self ,instance ,cls ):
677+ if instance is None :
678+ return self
679+ else :
680+ if self ._major :
681+ instance .majorTicks = [instance ._get_tick (major = True )]
682+ return instance .majorTicks
683+ else :
684+ instance .minorTicks = [instance ._get_tick (major = False )]
685+ return instance .minorTicks
686+
687+
665688class Axis (artist .Artist ):
666689"""
667690 Public attributes
@@ -696,8 +719,6 @@ def __init__(self, axes, pickradius=15):
696719self .label = self ._get_label ()
697720self .labelpad = rcParams ['axes.labelpad' ]
698721self .offsetText = self ._get_offset_text ()
699- self .majorTicks = []
700- self .minorTicks = []
701722self .unit_data = None
702723self .pickradius = pickradius
703724
@@ -708,6 +729,12 @@ def __init__(self, axes, pickradius=15):
708729self .cla ()
709730self ._set_scale ('linear' )
710731
732+ # During initialization, Axis objects often create ticks that are later
733+ # unused; this turns out to be a very slow step. Instead, use a custom
734+ # descriptor to make the tick lists lazy and instantiate them as needed.
735+ majorTicks = _LazyTickList (major = True )
736+ minorTicks = _LazyTickList (major = False )
737+
711738def set_label_coords (self ,x ,y ,transform = None ):
712739"""
713740 Set the coordinates of the label. By default, the x
@@ -798,12 +825,15 @@ def reset_ticks(self):
798825
799826 Each list starts with a single fresh Tick.
800827 """
801- del self .majorTicks [:]
802- del self .minorTicks [:]
803-
804- self .majorTicks .extend ([self ._get_tick (major = True )])
805- self .minorTicks .extend ([self ._get_tick (major = False )])
806-
828+ # Restore the lazy tick lists.
829+ try :
830+ del self .majorTicks
831+ except AttributeError :
832+ pass
833+ try :
834+ del self .minorTicks
835+ except AttributeError :
836+ pass
807837try :
808838self .set_clip_path (self .axes .patch )
809839except AttributeError :