00001 """
Place a legend on the axes at location loc. Labels are a
sequence of strings and loc can be a string or an integer
specifying the legend location
The location codes are
'best' : 0,
'upper right' : 1, (default)
'upper left' : 2,
'lower left' : 3,
'lower right' : 4,
'right' : 5,
'center left' : 6,
'center right' : 7,
'lower center' : 8,
'upper center' : 9,
'center' : 10,
Return value is a sequence of text, line instances that make
up the legend
"""
from __future__ import division
import sys, warnings
from numerix import array, ones, Float
from matplotlib import verbose, rcParams
from artist import Artist
from cbook import enumerate, is_string_like, iterable, silent_list
from font_manager import FontProperties
from lines import Line2D
from mlab import linspace, segments_intersect
from patches import Patch, Rectangle, RegularPolygon, Shadow, bbox_artist, draw_bbox
from collections import LineCollection, RegularPolyCollection, PatchCollection
from text import Text
from transforms import Bbox, Point, Value, get_bbox_transform, bbox_all,\
unit_bbox, inverse_transform_bbox, lbwh_to_bbox
00043 def line_cuts_bbox(line, bbox):
""" Return True if and only if line cuts bbox. """
minx, miny, width, height = bbox.get_bounds()
maxx = minx + width
maxy = miny + height
n = len(line)
if n == 0:
return False
if n == 1:
return bbox.contains(line[0][0], line[0][1])
p1 = line[0]
for p2 in line[1:]:
segment = (p1, p2)
for edge in (((minx, miny), (minx, maxy)),
((minx, miny), (maxx, miny)),
((maxx, miny), (maxx, maxy)),
((minx, maxy), (maxx, maxy))):
if segments_intersect(segment, edge):
return True
p1=p2
return False
00071 class Legend(Artist):
"""
Place a legend on the axes at location loc. Labels are a
sequence of strings and loc can be a string or an integer
specifying the legend location
The location codes are
'best' : 0,
'upper right' : 1, (default)
'upper left' : 2,
'lower left' : 3,
'lower right' : 4,
'right' : 5,
'center left' : 6,
'center right' : 7,
'lower center' : 8,
'upper center' : 9,
'center' : 10,
Return value is a sequence of text, line instances that make
up the legend
"""
codes = {'best' : 0,
'upper right' : 1,
'upper left' : 2,
'lower left' : 3,
'lower right' : 4,
'right' : 5,
'center left' : 6,
'center right' : 7,
'lower center' : 8,
'upper center' : 9,
'center' : 10,
}
zorder = 5
00112 def __init__(self, parent, handles, labels, loc,
isaxes= None,
numpoints = None,
prop = None,
pad = None,
markerscale = None,
labelsep = None,
handlelen = None,
handletextsep = None,
axespad = None,
shadow= None,
):
"""
parent # the artist that contains the legend
handles # a list of artists (lines, patches) to add to the legend
labels # a list of strings to label the legend
loc # a location code
isaxes=True # whether this is an axes legend
numpoints = 4 # the number of points in the legend line
fontprop = FontProperties(size='smaller') # the font property
pad = 0.2 # the fractional whitespace inside the legend border
markerscale = 0.6 # the relative size of legend markers vs. original
shadow # if True, draw a shadow behind legend
The following dimensions are in axes coords
labelsep = 0.005 # the vertical space between the legend entries
handlelen = 0.05 # the length of the legend lines
handletextsep = 0.02 # the space between the legend line and legend text
axespad = 0.02 # the border between the axes and legend edge
"""
Artist.__init__(self)
if is_string_like(loc) and not self.codes.has_key(loc):
warnings.warn('Unrecognized location %s. Falling back on upper right; valid locations are\n%s\t' %(loc, '\n\t'.join(self.codes.keys())))
if is_string_like(loc): loc = self.codes.get(loc, 1)
proplist=[numpoints, pad, markerscale, labelsep, handlelen, handletextsep, axespad, shadow, isaxes]
propnames=['numpoints', 'pad', 'markerscale', 'labelsep', 'handlelen', 'handletextsep', 'axespad', 'shadow', 'isaxes']
for name, value in zip(propnames,proplist):
if value is None:
value=rcParams["legend."+name]
setattr(self,name,value)
if prop is None:
self.prop=FontProperties(size=rcParams["legend.fontsize"])
else:
self.prop=prop
self.fontsize = self.prop.get_size_in_points()
if self.isaxes:
self.set_figure(parent.figure)
else:
self.set_figure(parent)
self.parent = parent
self.set_transform( get_bbox_transform( unit_bbox(), parent.bbox) )
self._loc = loc
left, top = 0.5, 0.5
if self.numpoints == 1:
self._xdata = array([left + self.handlelen*0.5])
else:
self._xdata = linspace(left, left + self.handlelen, self.numpoints)
textleft = left+ self.handlelen+self.handletextsep
self.texts = self._get_texts(labels, textleft, top)
self.legendHandles = self._get_handles(handles, self.texts)
if len(self.texts):
left, top = self.texts[-1].get_position()
HEIGHT = self._approx_text_height()*len(self.texts)
else:
HEIGHT = 0.2
bottom = top-HEIGHT
left -= self.handlelen + self.handletextsep + self.pad
self.legendPatch = Rectangle(
xy=(left, bottom), width=0.5, height=HEIGHT,
facecolor='w', edgecolor='k',
)
self._set_artist_props(self.legendPatch)
self._drawFrame = True
def _set_artist_props(self, a):
a.set_figure(self.figure)
a.set_transform(self._transform)
def _approx_text_height(self):
return self.fontsize/72.0*self.figure.dpi.get()/self.parent.bbox.height()
def draw(self, renderer):
if not self.get_visible(): return
renderer.open_group('legend')
self._update_positions(renderer)
if self._drawFrame:
if self.shadow:
shadow = Shadow(self.legendPatch, -0.005, -0.005)
shadow.draw(renderer)
self.legendPatch.draw(renderer)
if not len(self.legendHandles) and not len(self.texts): return
for h in self.legendHandles:
if h is not None:
h.draw(renderer)
if 0: bbox_artist(h, renderer)
for t in self.texts:
if 0: bbox_artist(t, renderer)
t.draw(renderer)
renderer.close_group('legend')
def _get_handle_text_bbox(self, renderer):
'Get a bbox for the text and lines in axes coords'
bboxesText = [t.get_window_extent(renderer) for t in self.texts]
bboxesHandles = [h.get_window_extent(renderer) for h in self.legendHandles if h is not None]
bboxesAll = bboxesText
bboxesAll.extend(bboxesHandles)
bbox = bbox_all(bboxesAll)
self.save = bbox
ibox = inverse_transform_bbox(self._transform, bbox)
self.ibox = ibox
return ibox
def _get_handles(self, handles, texts):
HEIGHT = self._approx_text_height()
ret = []
for handle, label in zip(handles, texts):
x, y = label.get_position()
x -= self.handlelen + self.handletextsep
if isinstance(handle, Line2D):
ydata = (y-HEIGHT/2)*ones(self._xdata.shape, Float)
legline = Line2D(self._xdata, ydata)
legline.update_from(handle)
self._set_artist_props(legline)
legline.set_clip_box(None)
legline.set_markersize(self.markerscale*legline.get_markersize())
ret.append(legline)
elif isinstance(handle, Patch):
p = Rectangle(xy=(min(self._xdata), y-3/4*HEIGHT),
width = self.handlelen, height=HEIGHT/2,
)
p.update_from(handle)
self._set_artist_props(p)
p.set_clip_box(None)
ret.append(p)
elif isinstance(handle, LineCollection):
ydata = (y-HEIGHT/2)*ones(self._xdata.shape, Float)
legline = Line2D(self._xdata, ydata)
self._set_artist_props(legline)
legline.set_clip_box(None)
lw = handle.get_linewidth()[0]
dashes = handle.get_dashes()
color = handle.get_colors()[0]
legline.set_color(color)
legline.set_linewidth(lw)
legline.set_dashes(dashes)
ret.append(legline)
elif isinstance(handle, RegularPolyCollection):
p = Rectangle(xy=(min(self._xdata), y-3/4*HEIGHT),
width = self.handlelen, height=HEIGHT/2,
)
p.set_facecolor(handle._facecolors[0])
if handle._edgecolors != 'None':
p.set_edgecolor(handle._edgecolors[0])
self._set_artist_props(p)
p.set_clip_box(None)
ret.append(p)
else:
ret.append(None)
return ret
00302 def _auto_legend_data(self):
""" Returns list of vertices and extents covered by the plot.
Returns a two long list.
First element is a list of (x, y) vertices (in
axes-coordinates) covered by all the lines and line
collections, in the legend's handles.
Second element is a list of bounding boxes for all the patches in
the legend's handles.
"""
if not self.isaxes:
raise Exception, 'Auto legends not available for figure legends.'
def get_handles(ax):
handles = ax.lines
handles.extend(ax.patches)
handles.extend([c for c in ax.collections if isinstance(c, LineCollection)])
return handles
ax = self.parent
handles = get_handles(ax)
vertices = []
bboxes = []
lines = []
inv = ax.transAxes.inverse_xy_tup
for handle in handles:
if isinstance(handle, Line2D):
xdata = handle.get_xdata(valid_only = True)
ydata = handle.get_ydata(valid_only = True)
trans = handle.get_transform()
xt, yt = trans.numerix_x_y(xdata, ydata)
averts = [inv(v) for v in zip(xt, yt)]
lines.append(averts)
elif isinstance(handle, Patch):
verts = handle.get_verts()
trans = handle.get_transform()
tverts = trans.seq_xy_tups(verts)
averts = [inv(v) for v in tverts]
bbox = unit_bbox()
bbox.update(averts, True)
bboxes.append(bbox)
elif isinstance(handle, LineCollection):
hlines = handle.get_lines()
trans = handle.get_transform()
for line in hlines:
tline = trans.seq_xy_tups(line)
aline = [inv(v) for v in tline]
lines.extend(line)
return [vertices, bboxes, lines]
def draw_frame(self, b):
'b is a boolean. Set draw frame to b'
self._drawFrame = b
def get_frame(self):
'return the Rectangle instance used to frame the legend'
return self.legendPatch
def get_lines(self):
'return a list of lines.Line2D instances in the legend'
return [h for h in self.legendHandles if isinstance(h, Line2D)]
def get_patches(self):
'return a list of patch instances in the legend'
return silent_list('Patch', [h for h in self.legendHandles if isinstance(h, Patch)])
def get_texts(self):
'return a list of text.Text instance in the legend'
return silent_list('Text', self.texts)
def _get_texts(self, labels, left, upper):
HEIGHT = self._approx_text_height()
pos = upper
x = left
ret = []
for l in labels:
text = Text(
x=x, y=pos,
text=l,
fontproperties=self.prop,
verticalalignment='top',
horizontalalignment='left',
)
self._set_artist_props(text)
ret.append(text)
pos -= HEIGHT
return ret
def get_window_extent(self):
return self.legendPatch.get_window_extent()
def _offset(self, ox, oy):
'Move all the artists by ox,oy (axes coords)'
for t in self.texts:
x,y = t.get_position()
t.set_position( (x+ox, y+oy) )
for h in self.legendHandles:
if isinstance(h, Line2D):
x,y = h.get_xdata(valid_only = True), h.get_ydata(valid_only = True)
h.set_data( x+ox, y+oy)
elif isinstance(h, Rectangle):
h.xy[0] = h.xy[0] + ox
h.xy[1] = h.xy[1] + oy
elif isinstance(h, RegularPolygon):
h.verts = [(x + ox, y + oy) for x, y in h.verts]
x, y = self.legendPatch.get_x(), self.legendPatch.get_y()
self.legendPatch.set_x(x+ox)
self.legendPatch.set_y(y+oy)
00434 def _find_best_position(self, width, height, consider=None):
"""Determine the best location to place the legend.
`consider` is a list of (x, y) pairs to consider as a potential
lower-left corner of the legend. All are axes coords.
"""
verts, bboxes, lines = self._auto_legend_data()
consider = [self._loc_to_axes_coords(x, width, height) for x in range(1, len(self.codes))]
tx, ty = self.legendPatch.xy
candidates = []
for l, b in consider:
legendBox = lbwh_to_bbox(l, b, width, height)
badness = 0
badness = legendBox.count_contains(verts)
ox, oy = l-tx, b-ty
for bbox in bboxes:
if legendBox.overlaps(bbox):
badness += 1
for line in lines:
if line_cuts_bbox(line, legendBox):
badness += 1
if badness == 0:
return ox, oy
candidates.append((badness, (ox, oy)))
minCandidate = candidates[0]
for candidate in candidates:
if candidate[0] < minCandidate[0]:
minCandidate = candidate
ox, oy = minCandidate[1]
return ox, oy
00479 def _loc_to_axes_coords(self, loc, width, height):
"""Convert a location code to axes coordinates.
- loc: a location code, which may be a pair of literal axes coords, or
in range(1, 11). This coresponds to the possible values for
self._loc, excluding "best".
- width, height: the final size of the legend, axes units.
"""
BEST, UR, UL, LL, LR, R, CL, CR, LC, UC, C = range(11)
left = self.axespad
right = 1.0 - (self.axespad + width)
upper = 1.0 - (self.axespad + height)
lower = self.axespad
centerx = 0.5 - (width/2.0)
centery = 0.5 - (height/2.0)
if loc == UR:
return right, upper
if loc == UL:
return left, upper
if loc == LL:
return left, lower
if loc == LR:
return right, lower
if loc == CL:
return left, centery
if loc in (CR, R):
return right, centery
if loc == LC:
return centerx, lower
if loc == UC:
return centerx, upper
if loc == C:
return centerx, centery
raise TypeError, "%r isn't an understood type code." % (loc,)
def _update_positions(self, renderer):
if not len(self.legendHandles) and not len(self.texts): return
def get_tbounds(text):
bbox = text.get_window_extent(renderer)
bboxa = inverse_transform_bbox(self._transform, bbox)
return bboxa.get_bounds()
hpos = []
for t, tabove in zip(self.texts[1:], self.texts[:-1]):
x,y = t.get_position()
l,b,w,h = get_tbounds(tabove)
b -= self.labelsep
h += 2*self.labelsep
hpos.append( (b,h) )
t.set_position( (x, b-0.1*h) )
l,b,w,h = get_tbounds(self.texts[-1])
b -= self.labelsep
h += 2*self.labelsep
hpos.append( (b,h) )
for handle, tup in zip(self.legendHandles, hpos):
y,h = tup
if isinstance(handle, Line2D):
ydata = y*ones(self._xdata.shape, Float)
handle.set_ydata(ydata+h/2)
elif isinstance(handle, Rectangle):
handle.set_y(y+1/4*h)
handle.set_height(h/2)
bbox = self._get_handle_text_bbox(renderer).deepcopy()
bbox.scale(1 + self.pad, 1 + self.pad)
l,b,w,h = bbox.get_bounds()
self.legendPatch.set_bounds(l,b,w,h)
BEST, UR, UL, LL, LR, R, CL, CR, LC, UC, C = range(11)
ox, oy = 0, 0
if iterable(self._loc) and len(self._loc)==2:
xo = self.legendPatch.get_x()
yo = self.legendPatch.get_y()
x, y = self._loc
ox = x-xo
oy = y-yo
self._offset(ox, oy)
else:
if self._loc in (BEST,):
ox, oy = self._find_best_position(w, h)
if self._loc in (UL, LL, CL):
ox = self.axespad - l
if self._loc in (UR, LR, R, CR):
ox = 1 - (l + w + self.axespad)
if self._loc in (UR, UL, UC):
oy = 1 - (b + h + self.axespad)
if self._loc in (LL, LR, LC):
oy = self.axespad - b
if self._loc in (LC, UC, C):
ox = (0.5-w/2)-l
if self._loc in (CL, CR, C):
oy = (0.5-h/2)-b
self._offset(ox, oy)