def draw(self, renderer):
renderer.open_group("regpolycollection")
self._transform.freeze()
self._transOffset.freeze()
self.update_scalarmappable()
scales = sqrt(self._sizes * self._dpi.get() / 72.0)
if self._edgecolors == "None":
self._edgecolors = self._facecolors
renderer.draw_regpoly_collection(
self.clipbox,
self._offsets,
self._transOffset,
self._verts,
scales,
self._facecolors,
self._edgecolors,
self._linewidths,
self._antialiaseds,
)
self._transform.thaw()
self._transOffset.thaw()
renderer.close_group("regpolycollection")
def line2d_dist(l, p):
"""
Distance from line to point
line is a tuple of coefficients a,b,c
"""
a, b, c = l
x0, y0 = p
return abs((a * x0 + b * y0 + c) / nx.sqrt(a**2 + b**2))
def dist2d(p0, p1):
"""distance between two points"""
try:
p = p0 - p1
return nx.sqrt(sum(p**2))
except ValueError:
print p0, p1
raise
def colorbars(epsoutfile):
x = (arange(50.0)-25)/2.0
y = (arange(50.0)-25)/2.0
r = sqrt(x[:,NewAxis]**2+y**2)
z = 5.0*cos(r)
colmap = ColMapper.ColorMapper("yellow-red", exponent=0.55, brightness=0.5)
lut = colmap.generate_lut()
c = pyx.canvas.canvas()
g = pyxgraph(xlimits=(min(x), max(x)), ylimits=(min(y), max(y)),
width=6, height=6)
g.pyxplot("y(x)=sin(x)", style="p") # FIXME: can't do empty plots!
g.pyxplotarray(z, colmap=lut)
c.insert(g)
minz = minvalue=min(ravel(z))
maxz = maxvalue=max(ravel(z))
# --- vertical bars
dist = 1.2
for orientation, position in [("vertical", "right"),
("vertical", "middle"),
("vertical2", "middle")]:
cb = pyxcolorbar(lut=lut, frame=g,
pos=(dist, 0),
orientation = orientation,
position = position,
minvalue = minz, maxvalue=maxz)
# add a short note on the style:
txt = orientation[0]
if "2" in orientation:
txt += "2"
txt += ", "+position[0]
cb.pyxlabel( (0.0, 1.3), txt, style=[pyx.text.halign.left])
c.insert(cb)
dist = dist + 0.5
# horizontal ones:
dist = -0.3
for orientation, position in [("horizontal", "middle"),
("horizontal2", "middle")]:
cb = pyxcolorbar(lut=lut, frame=g, pos=(0.0, dist),
orientation = orientation,
position = position,
minvalue = minz, maxvalue=maxz)
# add a short note on the style:
txt = orientation[0]
if "2" in orientation:
txt += "2"
txt += ", "+position[0]
cb.pyxlabel( (1.3, 0.5), txt, style=[pyx.text.halign.left])
c.insert(cb)
dist = dist - 0.3
pyxsave(c, epsoutfile)
def too_close(self, x,y, lw):
"if there's a label already nearby, find a better place"
if self.cl_xy != []:
dist = [sqrt((x-loc[0]) ** 2 + (y-loc[1]) ** 2) for loc in self.cl_xy]
for d in dist:
if d < 1.2*lw:
return 1
else: return 0
else: return 0
def __init__(self, x, y, dx, dy, width=1.0, **kwargs):
"""Draws an arrow, starting at (x,y), direction and length
given by (dx,dy) the width of the arrow is scaled by width
"""
arrow = array([[0.0, 0.1], [0.0, -0.1], [0.8, -0.1], [0.8, -0.3], [1.0, 0.0], [0.8, 0.3], [0.8, 0.1]])
L = sqrt(dx ** 2 + dy ** 2) or 1 # account for div by zero
arrow[:, 0] *= L
arrow[:, 1] *= width
cx = float(dx) / L
sx = float(dy) / L
M = array([[cx, sx], [-sx, cx]])
verts = matrixmultiply(arrow, M) + [x, y]
Polygon.__init__(self, [tuple(t) for t in verts], **kwargs)
def array_example1(epsoutfile):
x = (arange(50.0)-25)/2.0
y = (arange(50.0)-25)/2.0
r = sqrt(x[:,NewAxis]**2+y**2)
z = 5.0*sin(r)
g=pyxgraph(xlimits=(min(x), max(x)), ylimits=(min(y), max(y)),
width=6, height=6, key=False)
# WARNING: if key is not specified to be False, one gets a weird
# error ....
#g.pyxplot("y(x)=sin(x)", style="p") # FIXME: can't do empty plots!
g.pyxplotarray(z, colmap=ColMapper.ColorMapper("yellow-red",
exponent=0.55, brightness=0.5))
g.pyxsave(epsoutfile)
def get_ind_under_point(self, event):
'get the index of the vertex under point if within epsilon tolerance'
x, y = zip(*self.poly.verts)
# display coords
xt, yt = self.poly.get_transform().numerix_x_y(x, y)
d = sqrt((xt - event.x)**2 + (yt - event.y)**2)
indseq = nonzero(equal(d, amin(d)))
ind = indseq[0]
if d[ind] >= self.epsilon:
ind = None
return ind
def get_ind_under_point(self, event):
'get the index of the vertex under point if within epsilon tolerance'
x, y = zip(*self.poly.verts)
# display coords
xt, yt = self.poly.get_transform().numerix_x_y(x, y)
d = sqrt((xt-event.x)**2 + (yt-event.y)**2)
indseq = nonzero(equal(d, amin(d)))
ind = indseq[0]
if d[ind]>=self.epsilon:
ind = None
return ind
def __init__(self, x, y, dx, dy, width=1.0, **kwargs):
"""Draws an arrow, starting at (x,y), direction and length
given by (dx,dy) the width of the arrow is scaled by width
"""
arrow = array([[0.0, 0.1], [0.0, -0.1], [0.8, -0.1], [0.8, -0.3],
[1.0, 0.0], [0.8, 0.3], [0.8, 0.1]])
L = sqrt(dx**2 + dy**2) or 1 # account for div by zero
arrow[:, 0] *= L
arrow[:, 1] *= width
cx = float(dx) / L
sx = float(dy) / L
M = array([[cx, sx], [-sx, cx]])
verts = matrixmultiply(arrow, M) + [x, y]
Polygon.__init__(self, [tuple(t) for t in verts], **kwargs)
def locate_label(self, linecontour, labelwidth):
"""find a good place to plot a label (relatively flat
part of the contour) and the angle of rotation for the
text object
"""
nsize = len(linecontour)
if labelwidth > 1:
xsize = int(ceil(nsize / labelwidth))
else:
xsize = 1
if xsize == 1:
ysize = nsize
else:
ysize = labelwidth
XX = resize(asarray(linecontour)[:, 0], (xsize, ysize))
YY = resize(asarray(linecontour)[:, 1], (xsize, ysize))
yfirst = YY[:, 0]
ylast = YY[:, -1]
xfirst = XX[:, 0]
xlast = XX[:, -1]
s = ((reshape(yfirst, (xsize, 1)) - YY) *
(reshape(xlast, (xsize, 1)) - reshape(xfirst, (xsize, 1))) -
(reshape(xfirst, (xsize, 1)) - XX) *
(reshape(ylast, (xsize, 1)) - reshape(yfirst, (xsize, 1))))
L = sqrt((xlast - xfirst)**2 + (ylast - yfirst)**2)
dist = add.reduce(([(abs(s)[i] / L[i]) for i in range(xsize)]), -1)
x, y, ind = self.get_label_coords(dist, XX, YY, ysize, labelwidth)
#print 'ind, x, y', ind, x, y
angle = arctan2(ylast - yfirst, xlast - xfirst)
rotation = angle[ind] * 180 / pi
if rotation > 90:
rotation = rotation - 180
if rotation < -90:
rotation = 180 + rotation
# There must be a more efficient way...
lc = [tuple(l) for l in linecontour]
dind = lc.index((x, y))
#print 'dind', dind
#dind = list(linecontour).index((x,y))
return x, y, rotation, dind
def locate_label(self, linecontour, labelwidth):
"""find a good place to plot a label (relatively flat
part of the contour) and the angle of rotation for the
text object
"""
nsize= len(linecontour)
if labelwidth > 1:
xsize = int(ceil(nsize/labelwidth))
else:
xsize = 1
if xsize == 1:
ysize = nsize
else:
ysize = labelwidth
XX = resize(asarray(linecontour)[:,0],(xsize, ysize))
YY = resize(asarray(linecontour)[:,1],(xsize,ysize))
yfirst = YY[:,0]
ylast = YY[:,-1]
xfirst = XX[:,0]
xlast = XX[:,-1]
s = ( (reshape(yfirst, (xsize,1))-YY) *
(reshape(xlast,(xsize,1)) - reshape(xfirst,(xsize,1)))
- (reshape(xfirst,(xsize,1))-XX)
* (reshape(ylast,(xsize,1)) - reshape(yfirst,(xsize,1))) )
L=sqrt((xlast-xfirst)**2+(ylast-yfirst)**2)
dist = add.reduce(([(abs(s)[i]/L[i]) for i in range(xsize)]),-1)
x,y,ind = self.get_label_coords(dist, XX, YY, ysize, labelwidth)
#print 'ind, x, y', ind, x, y
angle = arctan2(ylast - yfirst, xlast - xfirst)
rotation = angle[ind]*180/pi
if rotation > 90:
rotation = rotation -180
if rotation < -90:
rotation = 180 + rotation
# There must be a more efficient way...
lc = [tuple(l) for l in linecontour]
dind = lc.index((x,y))
#print 'dind', dind
#dind = list(linecontour).index((x,y))
return x,y, rotation, dind
def draw(self, renderer):
renderer.open_group('regpolycollection')
self._transform.freeze()
self._transOffset.freeze()
self.update_scalarmappable()
scales = sqrt(self._sizes * self._dpi.get() / 72.0)
if self._edgecolors == 'None':
self._edgecolors = self._facecolors
renderer.draw_regpoly_collection(self.clipbox, self._offsets,
self._transOffset, self._verts,
scales, self._facecolors,
self._edgecolors, self._linewidths,
self._antialiaseds)
self._transform.thaw()
self._transOffset.thaw()
renderer.close_group('regpolycollection')
def array_example3(epsoutfile):
x = (arange(200.0) - 100) / 10.0
y = (arange(200.0) - 100) / 10.0
r = sqrt(x[:, NewAxis] ** 2 + y ** 2)
z = 5.0 * cos(r)
colmap1 = ColMapper.ColorMapper("red")
colmap1.exponent = 0.9
colmap1.invert = True
colmap2 = ColMapper.ColorMapper("green")
colmap2.exponent = 0.9
colmap3 = ColMapper.ColorMapper("green")
colmap3.invert = True
colmap3.exponent = 0.9
colmap4 = ColMapper.ColorMapper("blue")
colmap4.exponent = 0.9
colmap = ColMapper.SegmentedColorMapping(
[(-5.0, -2.5, colmap1), (-2.5, 0.0, colmap2), (0.0, 2.5, colmap3), (2.5, 5.0, colmap4)], -5.0, 5.0
)
# colmap = ColMapper.example_SegmentedColorMapping(min(ravel(z)),max(ravel(z)))
lut = colmap.generate_lut()
pilbitmap = ColMapper.Array2PIL(z, lut=lut)
c = pyx.canvas.canvas()
g = pyxgraph(xlimits=(min(x), max(x)), ylimits=(min(y), max(y)), width=6, height=6, key=False)
g.pyxplot("y(x)=sin(x)+20", style="p") # FIXME: can't do empty plots!
g.pyxbitmap(pilbitmap)
c.insert(g)
cb = pyxcolorbar(lut=lut, frame=g, pos=(1.1, 0.0), minvalue=min(ravel(z)), maxvalue=max(ravel(z)))
c.insert(cb)
pyxsave(c, epsoutfile)
def array_example2(epsoutfile):
x = (arange(50.0)-25)/2.0
y = (arange(50.0)-25)/2.0
r = sqrt(x[:,NewAxis]**2+y**2)
z = 5.0*cos(r)
colmap = ColMapper.ColorMapper("yellow-red", exponent=0.55, brightness=0.5)
lut = colmap.generate_lut()
c = pyx.canvas.canvas()
g = pyxgraph(xlimits=(min(x), max(x)), ylimits=(min(y), max(y)),
width=6, height=6)
g.pyxplot("y(x)=sin(x)", style="p") # FIXME: can't do empty plots!
g.pyxplotarray(z, colmap=lut)
c.insert(g)
cb = pyxcolorbar(lut=lut, frame=g, pos=(1.1,0.0),
minvalue=min(ravel(z)), maxvalue=max(ravel(z)))
c.insert(cb)
pyxsave(c, epsoutfile)
def draw(self, renderer):
if not self.get_visible(): return
renderer.open_group('regpolycollection')
self._transform.freeze()
self._transOffset.freeze()
self.update_scalarmappable()
self._update_verts()
scales = sqrt(asarray(self._sizes) * self._dpi.get() / 72.0)
if is_string_like(self._edgecolors) and self._edgecolors[:2] == 'No':
#self._edgecolors = self._facecolors
self._linewidths = (0, )
# print 'in draw(), self._offsets = %s' % (`self._offsets`)
renderer.draw_regpoly_collection(self.clipbox, self._offsets,
self._transOffset, self._verts,
scales, self._facecolors,
self._edgecolors, self._linewidths,
self._antialiaseds)
self._transform.thaw()
self._transOffset.thaw()
renderer.close_group('regpolycollection')
def pyxarrow(canvas, xystart, xyend, length=None, arrowstyle=None,
graphcoords=False):
"""
xystart=(,)
xyend=(,)
are coordinates from [0.0, 1.0]
relative to the canvas (or graph) area
(values outside of this range are also allowed).
If length is not None
the direction is specified by xystart,xyend
"""
if arrowstyle == None:
arrowstyle = [pyx.style.linewidth.THIck, pyx.deco.earrow.Large]
# print "canvas.xpos",canvas.xpos
# print "canvas.ypos",canvas.ypos
# print "canvas.width",canvas.width
# print "canvas.height",canvas.height
if graphcoords == True:
# canvas.pos only works after dolayout!
xmin = canvas.axes["x"].axis.min
xmax = canvas.axes["x"].axis.max
ymin = canvas.axes["y"].axis.min
ymax = canvas.axes["y"].axis.max
if xmin == None or ymin == None or xmax == None or ymax == None:
#if not canvas.did(canvas.dolayout):
# canvas.dolayout()
# print "forced dolayout here"
x0, y0 = canvas.pos(xystart[0], xystart[1])
x1, y1 = canvas.pos(xyend[0], xyend[1])
else:
def convertxy(position):
"""Convert from [0.0, 1.0] coordinates to canvas coordinates """
return ( (position[0]-xmin)/(xmax-xmin),
(position[1]-ymin)/(ymax-ymin) )
def convertxy_logx(position):
"""Convert from [0.0, 1.0] coordinates to canvas coordinates
on a logarithmic scale in x-direction"""
return ( (log(position[0])-log(xmin))/(log(xmax)-log(xmin)),
(position[1]-ymin)/(ymax-ymin) )
def convertxy_logy(position):
"""Convert from [0.0, 1.0] coordinates to canvas coordinates
on a logarithmic scale in y-direction"""
return ( (position[0]-xmin)/(xmax-xmin),
(log(position[1])-log(ymin))/(log(ymax)-log(ymin)) )
def convertxy_loglog(position):
"""Convert from [0.0, 1.0] coordinates to canvas coordinates
on a logarithmic scale in x- and y-direction"""
return ( (log(position[0])-log(xmin))/(log(xmax)-log(xmin)),
(log(position[1])-log(ymin))/(log(ymax)-log(ymin)) )
if canvas.xaxistype == "linear" and canvas.yaxistype == "linear":
xystart_normalized = convertxy(xystart)
xyend_normalized = convertxy(xyend)
elif canvas.xaxistype == "log" and canvas.yaxistype == "linear":
xystart_normalized = convertxy_logx(xystart)
xyend_normalized = convertxy_logx(xyend)
elif canvas.xaxistype == "linear" and canvas.yaxistype == "log":
xystart_normalized = convertxy_logy(xystart)
xyend_normalized = convertxy_logy(xyend)
elif canvas.xaxistype == "log" and canvas.yaxistype == "log":
xystart_normalized = convertxy_loglog(xystart)
xyend_normalized = convertxy_loglog(xyend)
else:
xystart_normalized = convertxy(xystart)
xyend_normalized = convertxy(xyend)
x0 = canvas.xpos+xystart_normalized[0]*canvas.width
x1 = canvas.xpos+xyend_normalized[0]*canvas.width
y0 = canvas.ypos+xystart_normalized[1]*canvas.height
y1 = canvas.ypos+xyend_normalized[1]*canvas.height
else:
x0 = canvas.xpos+xystart[0]*canvas.width
x1 = canvas.xpos+xyend[0]*canvas.width
y0 = canvas.ypos+xystart[1]*canvas.height
y1 = canvas.ypos+xyend[1]*canvas.height
if length != None:
dx = xyend[0]-xystart[0]
dy = xyend[1]-xystart[1]
norm = sqrt(dx**2+dy**2)
dx, dy = length*dx/norm, length*dy/norm
x1 = canvas.xpos+xyend[0]*canvas.width+dx*canvas.width
y1 = canvas.xpos+xyend[1]*canvas.height+dy*canvas.height
path = pyx.path.path(pyx.path.moveto(x0, y0), pyx.path.lineto(x1, y1))
canvas.stroke(path, arrowstyle)
def update_coords(self, renderer):
"""Computes the actual x,y coordinates for
text based on the input x,y and the
dashlength. Since the rotation is with respect
to the actual canvas's coordinates we need to
map back and forth.
"""
dashx, dashy = self.get_position()
dashlength = self.get_dashlength()
# Shortcircuit this process if we don't have a dash
if dashlength == 0.0:
self._x, self._y = dashx, dashy
return
dashrotation = self.get_dashrotation()
dashdirection = self.get_dashdirection()
dashpad = self.get_dashpad()
dashpush = self.get_dashpush()
angle = get_rotation(dashrotation)
theta = pi * (angle / 180.0 + dashdirection - 1)
cos_theta, sin_theta = cos(theta), sin(theta)
transform = self.get_transform()
# Compute the dash end points
# The 'c' prefix is for canvas coordinates
cxy = array(transform.xy_tup((dashx, dashy)))
cd = array([cos_theta, sin_theta])
c1 = cxy + dashpush * cd
c2 = cxy + (dashpush + dashlength) * cd
(x1, y1) = transform.inverse_xy_tup(tuple(c1))
(x2, y2) = transform.inverse_xy_tup(tuple(c2))
self.dashline.set_data((x1, x2), (y1, y2))
# We now need to extend this vector out to
# the center of the text area.
# The basic problem here is that we're "rotating"
# two separate objects but want it to appear as
# if they're rotated together.
# This is made non-trivial because of the
# interaction between text rotation and alignment -
# text alignment is based on the bbox after rotation.
# We reset/force both alignments to 'center'
# so we can do something relatively reasonable.
# There's probably a better way to do this by
# embedding all this in the object's transformations,
# but I don't grok the transformation stuff
# well enough yet.
we = Text.get_window_extent(self, renderer=renderer)
w, h = we.width(), we.height()
# Watch for zeros
if sin_theta == 0.0:
dx = w
dy = 0.0
elif cos_theta == 0.0:
dx = 0.0
dy = h
else:
tan_theta = sin_theta / cos_theta
dx = w
dy = w * tan_theta
if dy > h or dy < -h:
dy = h
dx = h / tan_theta
cwd = array([dx, dy]) / 2
cwd *= 1 + dashpad / sqrt(dot(cwd, cwd))
cw = c2 + (dashdirection * 2 - 1) * cwd
self._x, self._y = transform.inverse_xy_tup(tuple(cw))
# Now set the window extent
# I'm not at all sure this is the right way to do this.
we = Text.get_window_extent(self, renderer=renderer)
self._twd_window_extent = we.deepcopy()
self._twd_window_extent.update(((c1[0], c1[1]), ), False)
# Finally, make text align center
Text.set_horizontalalignment(self, 'center')
Text.set_verticalalignment(self, 'center')
def update_coords(self, renderer):
"""Computes the actual x,y coordinates for
self._mytext based on the input x,y and the
dashlength. Since the rotation is with respect
to the actual canvas's coordinates we need to
map back and forth.
"""
(x, y) = self.get_position()
dashlength = self.get_dashlength()
# Shortcircuit this process if we don't have a dash
if dashlength == 0.0:
self._mytext.set_position((x, y))
return
dashrotation = self.get_dashrotation()
dashdirection = self.get_dashdirection()
dashpad = self.get_dashpad()
dashpush = self.get_dashpush()
transform = self.get_transform()
angle = get_rotation(dashrotation)
theta = pi*(angle/180.0+dashdirection-1)
cos_theta, sin_theta = cos(theta), sin(theta)
# Compute the dash end points
# The 'c' prefix is for canvas coordinates
cxy = array(transform.xy_tup((x, y)))
cd = array([cos_theta, sin_theta])
c1 = cxy+dashpush*cd
c2 = cxy+(dashpush+dashlength)*cd
(x1, y1) = transform.inverse_xy_tup(tuple(c1))
(x2, y2) = transform.inverse_xy_tup(tuple(c2))
self.dashline.set_data((x1, x2), (y1, y2))
# We now need to extend this vector out to
# the center of the text area.
# The basic problem here is that we're "rotating"
# two separate objects but want it to appear as
# if they're rotated together.
# This is made non-trivial because of the
# interaction between text rotation and alignment -
# text alignment is based on the bbox after rotation.
# We reset/force both alignments to 'center'
# so we can do something relatively reasonable.
# There's probably a better way to do this by
# embedding all this in the object's transformations,
# but I don't grok the transformation stuff
# well enough yet.
we = self._mytext.get_window_extent(renderer=renderer)
w, h = we.width(), we.height()
# Watch for zeros
if sin_theta == 0.0:
dx = w
dy = 0.0
elif cos_theta == 0.0:
dx = 0.0
dy = h
else:
tan_theta = sin_theta/cos_theta
dx = w
dy = w*tan_theta
if dy > h or dy < -h:
dy = h
dx = h/tan_theta
cwd = array([dx, dy])/2
cwd *= 1+dashpad/sqrt(dot(cwd,cwd))
cw = c2+(dashdirection*2-1)*cwd
self._mytext.set_position(transform.inverse_xy_tup(tuple(cw)))
# Now set the window extent
# I'm not at all sure this is the right way to do this.
we = self._mytext.get_window_extent(renderer=renderer)
self._window_extent = we.deepcopy()
self._window_extent.update(((c1[0], c1[1]),), False)
# Finally, make text align center
self._mytext.set_horizontalalignment('center')
self._mytext.set_verticalalignment('center')
def __init__(
self,
x,
y,
dx,
dy,
width=0.001,
length_includes_head=False,
head_width=None,
head_length=None,
shape="full",
overhang=0,
head_starts_at_zero=False,
**kwargs
):
"""Returns a new Arrow.
length_includes_head: True if head is counted in calculating the length.
shape: ['full', 'left', 'right']
overhang: distance that the arrow is swept back (0 overhang means
triangular shape).
head_starts_at_zero: if True, the head starts being drawn at coordinate
0 instead of ending at coordinate 0.
"""
if head_width is None:
head_width = 3 * width
if head_length is None:
head_length = 1.5 * head_width
distance = sqrt(dx ** 2 + dy ** 2)
if length_includes_head:
length = distance
else:
length = distance + head_length
if not length:
verts = [] # display nothing if empty
else:
# start by drawing horizontal arrow, point at (0,0)
hw, hl, hs, lw = head_width, head_length, overhang, width
left_half_arrow = array(
[
[0.0, 0.0], # tip
[-hl, -hw / 2.0], # leftmost
[-hl * (1 - hs), -lw / 2.0], # meets stem
[-length, -lw / 2.0], # bottom left
[-length, 0],
]
)
# if we're not including the head, shift up by head length
if not length_includes_head:
left_half_arrow += [head_length, 0]
# if the head starts at 0, shift up by another head length
if head_starts_at_zero:
left_half_arrow += [head_length / 2.0, 0]
# figure out the shape, and complete accordingly
if shape == "left":
coords = left_half_arrow
else:
right_half_arrow = left_half_arrow * [1, -1]
if shape == "right":
coords = right_half_arrow
elif shape == "full":
coords = concatenate([left_half_arrow, right_half_arrow[::-1]])
else:
raise ValueError, "Got unknown shape: %s" % shape
cx = float(dx) / distance
sx = float(dy) / distance
M = array([[cx, sx], [-sx, cx]])
verts = matrixmultiply(coords, M) + (x + dx, y + dy)
Polygon.__init__(self, map(tuple, verts), **kwargs)
def __init__(self, x, y, dx, dy, width=0.001, length_includes_head=False, \
head_width=None, head_length=None, shape='full', overhang=0, \
head_starts_at_zero=False,**kwargs):
"""Returns a new Arrow.
length_includes_head: True if head is counted in calculating the length.
shape: ['full', 'left', 'right']
overhang: distance that the arrow is swept back (0 overhang means
triangular shape).
head_starts_at_zero: if True, the head starts being drawn at coordinate
0 instead of ending at coordinate 0.
"""
if head_width is None:
head_width = 3 * width
if head_length is None:
head_length = 1.5 * head_width
distance = sqrt(dx**2 + dy**2)
if length_includes_head:
length = distance
else:
length = distance + head_length
if not length:
verts = [] #display nothing if empty
else:
#start by drawing horizontal arrow, point at (0,0)
hw, hl, hs, lw = head_width, head_length, overhang, width
left_half_arrow = array([
[0.0, 0.0], #tip
[-hl, -hw / 2.0], #leftmost
[-hl * (1 - hs), -lw / 2.0], #meets stem
[-length, -lw / 2.0], #bottom left
[-length, 0],
])
#if we're not including the head, shift up by head length
if not length_includes_head:
left_half_arrow += [head_length, 0]
#if the head starts at 0, shift up by another head length
if head_starts_at_zero:
left_half_arrow += [head_length / 2.0, 0]
#figure out the shape, and complete accordingly
if shape == 'left':
coords = left_half_arrow
else:
right_half_arrow = left_half_arrow * [1, -1]
if shape == 'right':
coords = right_half_arrow
elif shape == 'full':
coords = concatenate(
[left_half_arrow, right_half_arrow[::-1]])
else:
raise ValueError, "Got unknown shape: %s" % shape
cx = float(dx) / distance
sx = float(dy) / distance
M = array([[cx, sx], [-sx, cx]])
verts = matrixmultiply(coords, M) + (x + dx, y + dy)
Polygon.__init__(self, map(tuple, verts), **kwargs)
def mod(v):
"""3d vector length"""
return nx.sqrt(v[0]**2 + v[1]**2 + v[2]**2)
