yale

Last crawled date: 1 year, 11 months ago

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"

@docstring.dedent_interpd
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.set_capstyle('projecting')
self.axis = None

self.set_zorder(2.5)
self.set_transform(self.axes.transData) # default transform

self._bounds = None # default bounds
self._smart_bounds = False

# 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
if not isinstance(path, matplotlib.path.Path):
msg = "'path' must be an instance of 'matplotlib.path.Path'"
raise ValueError(msg)
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()

def set_smart_bounds(self, value):
"""set the spine and associated axis to have smart bounds"""
self._smart_bounds = value

# also set the axis if possible
if self.spine_type in ('left', 'right'):
self.axes.yaxis.set_smart_bounds(value)
elif self.spine_type in ('top', 'bottom'):
self.axes.xaxis.set_smart_bounds(value)
self.stale = True

def get_smart_bounds(self):
"""get whether the spine has smart bounds"""
return self._smart_bounds

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
# circle drawn on axes transform
self.set_transform(self.axes.transAxes)
self.stale = True

def set_patch_line(self):
"""set the spine to be linear"""
self._patch_type = 'line'
self.stale = True

# 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()
self.stale = True

def cla(self):
"""Clear the current spine"""
self._position = None # clear position
if self.axis is not None:
self.axis.cla()

def is_frame_like(self):
"""return True if directly on axes frame

This is useful for determining if a spine is the edge of an
old style MPL plot. If so, this function will return True.
"""
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)
if len(position) != 2:
raise ValueError("position should be 2-tuple")
position_type, amount = position
if position_type == 'outward' and amount == 0:
return True
else:
return False

def _adjust_location(self):
"""automatically set spine bounds to the view interval"""

if self.spine_type == 'circle':
return

if self._bounds is None:
if self.spine_type in ('left', 'right'):
low, high = self.axes.viewLim.intervaly
elif self.spine_type in ('top', 'bottom'):
low, high = self.axes.viewLim.intervalx
else:
raise ValueError('unknown spine spine_type: %s' %
self.spine_type)

if self._smart_bounds:
# attempt to set bounds in sophisticated way
if low > high:
# handle inverted limits
low, high = high, low

viewlim_low = low
viewlim_high = high

del low, high

if self.spine_type in ('left', 'right'):
datalim_low, datalim_high = self.axes.dataLim.intervaly
ticks = self.axes.get_yticks()
elif self.spine_type in ('top', 'bottom'):
datalim_low, datalim_high = self.axes.dataLim.intervalx
ticks = self.axes.get_xticks()
# handle inverted limits
ticks = list(ticks)
ticks.sort()
ticks = np.array(ticks)
if datalim_low > datalim_high:
datalim_low, datalim_high = datalim_high, datalim_low

if datalim_low < viewlim_low:
# Data extends past view. Clip line to view.
low = viewlim_low
else:
# Data ends before view ends.
cond = (ticks <= datalim_low) & (ticks >= viewlim_low)
tickvals = ticks[cond]
if len(tickvals):
# A tick is less than or equal to lowest data point.
low = tickvals[-1]
else:
# No tick is available
low = datalim_low
low = max(low, viewlim_low)

if datalim_high > viewlim_high:
# Data extends past view. Clip line to view.
high = viewlim_high
else:
# Data ends before view ends.
cond = (ticks >= datalim_high) & (ticks <= viewlim_high)
tickvals = ticks[cond]
if len(tickvals):
# A tick is greater than or equal to highest data
# point.
high = tickvals[0]
else:
# No tick is available
high = datalim_high
high = min(high, viewlim_high)

else:
low, high = self._bounds

v1 = self._path.vertices
assert v1.shape == (2, 2), 'unexpected vertices shape'
if self.spine_type in ['left', 'right']:
v1[0, 1] = low
v1[1, 1] = high
elif self.spine_type in ['bottom', 'top']:
v1[0, 0] = low
v1[1, 0] = high
else:
raise ValueError('unable to set bounds for spine "%s"' %
self.spine_type)

@allow_rasterization
def draw(self, renderer):
self._adjust_location()
ret = super(Spine, self).draw(renderer)
self.stale = False
return ret

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.from_values(
# keep y unchanged, fix x at
# amount
0, 0, 0, 1, amount, 0))
elif self.spine_type in ('bottom', 'top'):
self._spine_transform = ('pre',
mtransforms.Affine2D.from_values(
# keep x unchanged, fix y at
# amount
1, 0, 0, 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 ('right', 'top'):
# The right and top spines have a default position of 1 in
# axes coordinates. When specifying the position in data
# coordinates, we need to calculate the position relative to 0.
amount -= 1
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:
if len(position) != 2:
raise ValueError("position should be 'center' or 2-tuple")
if position[0] not in ['outward', 'axes', 'data']:
msg = ("position[0] should be in [ 'outward' | 'axes' |"
" 'data' ]")
raise ValueError(msg)
self._position = position
self._calc_offset_transform()

self.set_transform(self.get_spine_transform())

if self.axis is not None:
self.axis.reset_ticks()
self.stale = True

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
data_xform = self.axes.transScale + \
(how + self.axes.transLimits + self.axes.transAxes)
if self.spine_type in ['left', 'right']:
result = mtransforms.blended_transform_factory(
data_xform, self.axes.transData)
elif self.spine_type in ['top', 'bottom']:
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)

def set_bounds(self, low, high):
"""Set the bounds of the spine."""
if self.spine_type == 'circle':
raise ValueError(
'set_bounds() method incompatible with circular spines')
self._bounds = (low, high)
self.stale = True

def get_bounds(self):
"""Get the bounds of the spine."""
return self._bounds

@classmethod
def linear_spine(cls, axes, spine_type, **kwargs):
"""
(staticmethod) Returns a linear :class:`Spine`.
"""
# all values of 13 get replaced upon call to set_bounds()
if spine_type == 'left':
path = mpath.Path([(0.0, 13), (0.0, 13)])
elif spine_type == 'right':
path = mpath.Path([(1.0, 13), (1.0, 13)])
elif spine_type == 'bottom':
path = mpath.Path([(13, 0.0), (13, 0.0)])
elif spine_type == 'top':
path = mpath.Path([(13, 1.0), (13, 1.0)])
else:
raise ValueError('unable to make path for spine "%s"' % spine_type)
result = cls(axes, spine_type, path, **kwargs)
result.set_visible(rcParams['axes.spines.{0}'.format(spine_type)])

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