from __future__ import division
import matplotlib
rcParams = matplotlib.rcParams
import matplotlib.artist as martist
from matplotlib.artist import allow_rasterization
import matplotlib.transforms as mtransforms
import matplotlib.lines as mlines
import matplotlib.patches as mpatches
import matplotlib.path as mpath
import matplotlib.cbook as cbook
import warnings
class Spine(mpatches.Patch):
"""an axis spine -- the line noting the data area boundaries
Spines are the lines connecting the axis tick marks and noting the
boundaries of the data area. They can be placed at arbitrary
positions. See function:`~matplotlib.spines.Spine.set_position`
for more information.
The default position is ``('outward',0)``.
Spines are subclasses of class:`~matplotlib.patches.Patch`, and
inherit much of their behavior.
Spines draw a line or a circle, depending if
function:`~matplotlib.spines.Spine.set_patch_line` or
function:`~matplotlib.spines.Spine.set_patch_circle` has been
called. Line-like is the default.
"""
def __str__(self):
return "Spine"
def __init__(self,axes,spine_type,path,**kwargs):
"""
- *axes* : the Axes instance containing the spine
- *spine_type* : a string specifying the spine type
- *path* : the path instance used to draw the spine
Valid kwargs are:
%(Patch)s
"""
super(Spine,self).__init__(**kwargs)
self.axes = axes
self.set_figure(self.axes.figure)
self.spine_type = spine_type
self.set_facecolor('none')
self.set_edgecolor( rcParams['axes.edgecolor'] )
self.set_linewidth(rcParams['axes.linewidth'])
self.axis = None
self.set_zorder(2.5)
self.set_transform(self.axes.transAxes) # default transform
# Defer initial position determination. (Not much support for
# non-rectangular axes is currently implemented, and this lets
# them pass through the spines machinery without errors.)
self._position = None
assert isinstance(path,matplotlib.path.Path)
self._path = path
# To support drawing both linear and circular spines, this
# class implements Patch behavior two ways. If
# self._patch_type == 'line', behave like a mpatches.PathPatch
# instance. If self._patch_type == 'circle', behave like a
# mpatches.Ellipse instance.
self._patch_type = 'line'
# Behavior copied from mpatches.Ellipse:
# Note: This cannot be calculated until this is added to an Axes
self._patch_transform = mtransforms.IdentityTransform()
__init__.__doc__ = cbook.dedent(__init__.__doc__) % martist.kwdocd
def set_patch_circle(self,center,radius):
"""set the spine to be circular"""
self._patch_type = 'circle'
self._center = center
self._width = radius*2
self._height = radius*2
self._angle = 0
def set_patch_line(self):
"""set the spine to be linear"""
self._patch_type = 'line'
# Behavior copied from mpatches.Ellipse:
def _recompute_transform(self):
"""NOTE: This cannot be called until after this has been added
to an Axes, otherwise unit conversion will fail. This
maxes it very important to call the accessor method and
not directly access the transformation member variable.
"""
assert self._patch_type == 'circle'
center = (self.convert_xunits(self._center[0]),
self.convert_yunits(self._center[1]))
width = self.convert_xunits(self._width)
height = self.convert_yunits(self._height)
self._patch_transform = mtransforms.Affine2D() \
.scale(width * 0.5, height * 0.5) \
.rotate_deg(self._angle) \
.translate(*center)
def get_patch_transform(self):
if self._patch_type == 'circle':
self._recompute_transform()
return self._patch_transform
else:
return super(Spine,self).get_patch_transform()
def get_path(self):
return self._path
def _ensure_position_is_set(self):
if self._position is None:
# default position
self._position = ('outward',0.0) # in points
self.set_position(self._position)
def register_axis(self,axis):
"""register an axis
An axis should be registered with its corresponding spine from
the Axes instance. This allows the spine to clear any axis
properties when needed.
"""
self.axis = axis
if self.axis is not None:
self.axis.cla()
def cla(self):
'Clear the current spine'
self._position = None # clear position
if self.axis is not None:
self.axis.cla()
def _calc_offset_transform(self):
"""calculate the offset transform performed by the spine"""
self._ensure_position_is_set()
position = self._position
if cbook.is_string_like(position):
if position=='center':
position = ('axes',0.5)
elif position=='zero':
position = ('data',0)
assert len(position)==2, "position should be 2-tuple"
position_type, amount = position
assert position_type in ('axes','outward','data')
if position_type=='outward':
if amount == 0:
# short circuit commonest case
self._spine_transform = ('identity',mtransforms.IdentityTransform())
elif self.spine_type in ['left','right','top','bottom']:
offset_vec = {'left':(-1,0),
'right':(1,0),
'bottom':(0,-1),
'top':(0,1),
}[self.spine_type]
# calculate x and y offset in dots
offset_x = amount*offset_vec[0]/ 72.0
offset_y = amount*offset_vec[1]/ 72.0
self._spine_transform = ('post',
mtransforms.ScaledTranslation(offset_x,offset_y,
self.figure.dpi_scale_trans))
else:
warnings.warn('unknown spine type "%s": no spine '
'offset performed'%self.spine_type)
self._spine_transform = ('identity',mtransforms.IdentityTransform())
elif position_type=='axes':
if self.spine_type in ('left','right'):
self._spine_transform = ('pre',
mtransforms.Affine2D().translate(amount, 0.0))
elif self.spine_type in ('bottom','top'):
self._spine_transform = ('pre',
mtransforms.Affine2D().translate(0.0, amount))
else:
warnings.warn('unknown spine type "%s": no spine '
'offset performed'%self.spine_type)
self._spine_transform = ('identity',mtransforms.IdentityTransform())
elif position_type=='data':
if self.spine_type in ('left','right'):
self._spine_transform = ('data',
mtransforms.Affine2D().translate(amount,0))
elif self.spine_type in ('bottom','top'):
self._spine_transform = ('data',
mtransforms.Affine2D().translate(0,amount))
else:
warnings.warn('unknown spine type "%s": no spine '
'offset performed'%self.spine_type)
self._spine_transform = ('identity',mtransforms.IdentityTransform())
def set_position(self,position):
"""set the position of the spine
Spine position is specified by a 2 tuple of (position type,
amount). The position types are:
* 'outward' : place the spine out from the data area by the
specified number of points. (Negative values specify placing the
spine inward.)
* 'axes' : place the spine at the specified Axes coordinate (from
0.0-1.0).
* 'data' : place the spine at the specified data coordinate.
Additionally, shorthand notations define a special positions:
* 'center' -> ('axes',0.5)
* 'zero' -> ('data', 0.0)
"""
if position in ('center','zero'):
# special positions
pass
else:
assert len(position)==2, "position should be 'center' or 2-tuple"
assert position[0] in ['outward','axes','data']
self._position = position
self._calc_offset_transform()
t = self.get_spine_transform()
if self.spine_type in ['left','right']:
t2 = mtransforms.blended_transform_factory(t,
self.axes.transAxes)
elif self.spine_type in ['bottom','top']:
t2 = mtransforms.blended_transform_factory(self.axes.transAxes,
t)
self.set_transform(t2)
if self.axis is not None:
self.axis.cla()
def get_position(self):
"""get the spine position"""
self._ensure_position_is_set()
return self._position
def get_spine_transform(self):
"""get the spine transform"""
self._ensure_position_is_set()
what, how = self._spine_transform
if what == 'data':
# special case data based spine locations
if self.spine_type in ['left','right']:
data_xform = self.axes.transScale + \
(how+self.axes.transLimits + self.axes.transAxes)
result = mtransforms.blended_transform_factory(
data_xform,self.axes.transData)
elif self.spine_type in ['top','bottom']:
data_xform = self.axes.transScale + \
(how+self.axes.transLimits + self.axes.transAxes)
result = mtransforms.blended_transform_factory(
self.axes.transData,data_xform)
else:
raise ValueError('unknown spine spine_type: %s'%self.spine_type)
return result
if self.spine_type in ['left','right']:
base_transform = self.axes.get_yaxis_transform(which='grid')
elif self.spine_type in ['top','bottom']:
base_transform = self.axes.get_xaxis_transform(which='grid')
else:
raise ValueError('unknown spine spine_type: %s'%self.spine_type)
if what=='identity':
return base_transform
elif what=='post':
return base_transform+how
elif what=='pre':
return how+base_transform
else:
raise ValueError("unknown spine_transform type: %s"%what)
@classmethod
def linear_spine(cls, axes, spine_type, **kwargs):
"""
(staticmethod) Returns a linear :class:`Spine`.
"""
if spine_type=='left':
path = mpath.Path([(0.0, 0.0), (0.0, 1.0)])
elif spine_type=='right':
path = mpath.Path([(1.0, 0.0), (1.0, 1.0)])
elif spine_type=='bottom':
path = mpath.Path([(0.0, 0.0), (1.0, 0.0)])
elif spine_type=='top':
path = mpath.Path([(0.0, 1.0), (1.0, 1.0)])
else:
raise ValueError('unable to make path for spine "%s"'%spine_type)
result = cls(axes,spine_type,path,**kwargs)
return result
@classmethod
def circular_spine(cls,axes,center,radius,**kwargs):
"""
(staticmethod) Returns a circular :class:`Spine`.
"""
path = mpath.Path.unit_circle()
spine_type = 'circle'
result = cls(axes,spine_type,path,**kwargs)
result.set_patch_circle(center,radius)
return result
def set_color(self, c):
"""
Set the edgecolor.
ACCEPTS: matplotlib color arg or sequence of rgba tuples
.. seealso::
:meth:`set_facecolor`, :meth:`set_edgecolor`
For setting the edge or face color individually.
"""
# The facecolor of a spine is always 'none' by default -- let
# the user change it manually if desired.
self.set_edgecolor(c)
