def plot2d(self, depth=None):
# FIXME: refactor this before publishing
from sage.plot.line import line
from sage.plot.graphics import Graphics
if self._n != 2:
raise ValueError("Can only 2d plot fans.")
if depth == None:
depth = self._depth
if not self.is_finite() and depth == infinity:
raise ValueError(
"For infinite algebras you must specify the depth.")
colors = dict([(0, 'red'), (1, 'green')])
G = Graphics()
for i in range(2):
orbit = self.ith_orbit(i, depth=depth)
for j in orbit:
G += line([(0, 0), vector(orbit[j])],
color=colors[i],
thickness=0.5,
zorder=2 * j + 1)
G.set_aspect_ratio(1)
G._show_axes = False
return G
def plot_fan_stereographically(rays, walls, northsign=1, north=vector((-1,-1,-1)), right=vector((1,0,0)), colors=None, thickness=None):
from sage.plot.graphics import Graphics
from sage.plot.point import point
from sage.misc.flatten import flatten
from sage.plot.line import line
from sage.misc.functional import norm
if colors == None:
colors = dict([('walls','black'),('rays','red')])
if thickness == None:
thickness = dict([('walls',0.5),('rays',20)])
G = Graphics()
for (u,v) in walls:
G += _stereo_arc(vector(u),vector(v),vector(u+v),north=northsign*north,right=right,color=colors['walls'],thickness=thickness['walls'],zorder=len(G))
for v in rays:
G += point(_stereo_coordinates(vector(v),north=northsign*north,right=right),color=colors['rays'],zorder=len(G),size=thickness['rays'])
G.set_aspect_ratio(1)
G._show_axes = False
return G
def plot_cluster_fan_stereographically(self, northsign=1, north=None, right=None, colors=None):
from sage.plot.graphics import Graphics
from sage.plot.point import point
from sage.misc.flatten import flatten
from sage.plot.line import line
from sage.misc.functional import norm
if self.rk !=3:
raise ValueError("Can only stereographically project fans in 3d.")
if not self.is_finite() and self._depth == infinity:
raise ValueError("For infinite algebras you must specify the depth.")
if north == None:
if self.is_affine():
north = vector(self.delta())
else:
north = vector( (-1,-1,-1) )
if right == None:
if self.is_affine():
right = vector(self.gamma())
else:
right = vector( (1,0,0) )
if colors == None:
colors = dict([(0,'red'),(1,'green'),(2,'blue'),(3,'cyan'),(4,'yellow')])
G = Graphics()
roots = list(self.g_vectors())
compatible = []
while roots:
x = roots.pop()
for y in roots:
if self.compatibility_degree(x,y) == 0:
compatible.append((x,y))
for (u,v) in compatible:
G += _stereo_arc(vector(u),vector(v),vector(u+v),north=northsign*north,right=right,thickness=0.5,color='black')
for i in range(3):
orbit = self.ith_orbit(i)
for j in orbit:
G += point(_stereo_coordinates(vector(orbit[j]),north=northsign*north,right=right),color=colors[i],zorder=len(G))
if self.is_affine():
tube_vectors = map(vector,flatten(self.affine_tubes()))
for v in tube_vectors:
G += point(_stereo_coordinates(v,north=northsign*north,right=right),color=colors[3],zorder=len(G))
if north != vector(self.delta()):
G += _stereo_arc(tube_vectors[0],tube_vectors[1],vector(self.delta()),north=northsign*north,right=right,thickness=2,color=colors[4],zorder=0)
else:
# FIXME: refactor this before publishing
tube_projections = [
_stereo_coordinates(v,north=northsign*north,right=right)
for v in tube_vectors ]
t=min((G.get_minmax_data()['xmax'],G.get_minmax_data()['ymax']))
G += line([tube_projections[0],tube_projections[0]+t*(_normalize(tube_projections[0]-tube_projections[1]))],thickness=2,color=colors[4],zorder=0)
G += line([tube_projections[1],tube_projections[1]+t*(_normalize(tube_projections[1]-tube_projections[0]))],thickness=2,color=colors[4],zorder=0)
G.set_aspect_ratio(1)
G._show_axes = False
return G
def plot(self, geosub, color=None):
r"""
EXAMPLES::
sage: from EkEkstar import kFace, kPatch, GeoSub
sage: sub = {1:[1,2], 2:[1,3], 3:[1]}
sage: geosub = GeoSub(sub,2, dual=True)
sage: P = kPatch([kFace((0,0,0),(1,2),dual=True),
....: kFace((0,0,1),(1,3),dual=True),
....: kFace((0,1,0),(2,1),dual=True),
....: kFace((0,0,0),(3,1),dual=True)])
sage: _ = P.plot(geosub)
"""
G = Graphics()
for face, m in self:
G += face._plot(geosub, color)
G.set_aspect_ratio(1)
return G
def plot2d(self,depth=None):
# FIXME: refactor this before publishing
from sage.plot.line import line
from sage.plot.graphics import Graphics
if self._n !=2:
raise ValueError("Can only 2d plot fans.")
if depth == None:
depth = self._depth
if not self.is_finite() and depth==infinity:
raise ValueError("For infinite algebras you must specify the depth.")
colors = dict([(0,'red'),(1,'green')])
G = Graphics()
for i in range(2):
orbit = self.ith_orbit(i,depth=depth)
for j in orbit:
G += line([(0,0),vector(orbit[j])],color=colors[i],thickness=0.5, zorder=2*j+1)
G.set_aspect_ratio(1)
G._show_axes = False
return G
def _graphics(self, plot_curve, ambient_coords, thickness=1,
aspect_ratio='automatic', color='red', style='-',
label_axes=True):
r"""
Plot a 2D or 3D curve in a Cartesian graph with axes labeled by
the ambient coordinates; it is invoked by the methods
:meth:`plot` of
:class:`~sage.manifolds.differentiable.curve.DifferentiableCurve`,
and its subclasses
(:class:`~sage.manifolds.differentiable.integrated_curve.IntegratedCurve`,
:class:`~sage.manifolds.differentiable.integrated_curve.IntegratedAutoparallelCurve`,
and
:class:`~sage.manifolds.differentiable.integrated_curve.IntegratedGeodesic`).
TESTS::
sage: M = Manifold(2, 'R^2')
sage: X.<x,y> = M.chart()
sage: R.<t> = RealLine()
sage: c = M.curve([cos(t), sin(t)], (t, 0, 2*pi), name='c')
sage: graph = c._graphics([[1,2], [3,4]], [x,y])
sage: graph._objects[0].xdata == [1,3]
True
sage: graph._objects[0].ydata == [2,4]
True
sage: graph._objects[0]._options['thickness'] == 1
True
sage: graph._extra_kwds['aspect_ratio'] == 'automatic'
True
sage: graph._objects[0]._options['rgbcolor'] == 'red'
True
sage: graph._objects[0]._options['linestyle'] == '-'
True
sage: l = [r'$'+latex(x)+r'$', r'$'+latex(y)+r'$']
sage: graph._extra_kwds['axes_labels'] == l
True
"""
from sage.plot.graphics import Graphics
from sage.plot.line import line
from sage.manifolds.utilities import set_axes_labels
#
# The plot
#
n_pc = len(ambient_coords)
resu = Graphics()
resu += line(plot_curve, color=color, linestyle=style,
thickness=thickness)
if n_pc == 2: # 2D graphic
resu.set_aspect_ratio(aspect_ratio)
if label_axes:
# We update the dictionary _extra_kwds (options to be passed
# to show()), instead of using the method
# Graphics.axes_labels() since the latter is not robust w.r.t.
# graph addition
resu._extra_kwds['axes_labels'] = [r'$'+latex(pc)+r'$'
for pc in ambient_coords]
else: # 3D graphic
if aspect_ratio == 'automatic':
aspect_ratio = 1
resu.aspect_ratio(aspect_ratio)
if label_axes:
labels = [str(pc) for pc in ambient_coords]
resu = set_axes_labels(resu, *labels)
return resu
def plot(self, chart=None, ambient_coords=None, mapping=None, prange=None,
include_end_point=(True, True), end_point_offset=(0.001, 0.001),
max_value=8, parameters=None, color='red', style='-',
thickness=1, plot_points=75, label_axes=True,
aspect_ratio='automatic'):
r"""
Plot the current curve (``self``) in a Cartesian graph based on the
coordinates of some ambient chart.
The curve is drawn in terms of two (2D graphics) or three (3D graphics)
coordinates of a given chart, called hereafter the *ambient chart*.
The ambient chart's domain must overlap with the curve's codomain or
with the codomain of the composite curve `\Phi\circ c`, where `c` is
``self`` and `\Phi` some manifold differential mapping (argument
``mapping`` below).
INPUT:
- ``chart`` -- (default: ``None``) the ambient chart (see above);
if ``None``, the default chart of the codomain of the curve (or of
the curve composed with `\Phi`) is used
- ``ambient_coords`` -- (default: ``None``) tuple containing the 2 or 3
coordinates of the ambient chart in terms of which the plot is
performed; if ``None``, all the coordinates of the ambient chart are
considered
- ``mapping`` -- (default: ``None``) differentiable mapping `\Phi`
(instance of
:class:`~sage.geometry.manifolds.diffmapping.DiffMapping`)
providing the link between ``self`` and the ambient chart ``chart``
(cf. above); if ``None``, the ambient chart is supposed to be defined
on the codomain of the curve ``self``.
- ``prange`` -- (default: ``None``) range of the curve parameter for
the plot; if ``None``, the entire parameter range declared during the
curve construction is considered (with -Infinity
replaced by ``-max_value`` and +Infinity by ``max_value``)
- ``include_end_point`` -- (default: ``(True, True)``) determines
whether the end points of ``prange`` are included in the plot
- ``end_point_offset`` -- (default: ``(0.001, 0.001)``) offsets from
the end points when they are not included in the plot: if
``include_end_point[0] == False``, the minimal value of the curve
parameter used for the plot is ``prange[0] + end_point_offset[0]``,
while if ``include_end_point[1] == False``, the maximal value is
``prange[1] - end_point_offset[1]``.
- ``max_value`` -- (default: 8) numerical value substituted to
+Infinity if the latter is the upper bound of the parameter range;
similarly ``-max_value`` is the numerical valued substituted for
-Infinity
- ``parameters`` -- (default: ``None``) dictionary giving the numerical
values of the parameters that may appear in the coordinate expression
of ``self``
- ``color`` -- (default: 'red') color of the drawn curve
- ``style`` -- (default: '-') color of the drawn curve; NB: ``style``
is effective only for 2D plots
- ``thickness`` -- (default: 1) thickness of the drawn curve
- ``plot_points`` -- (default: 75) number of points to plot the curve
- ``label_axes`` -- (default: ``True``) boolean determining whether the
labels of the coordinate axes of ``chart`` shall be added to the
graph; can be set to ``False`` if the graph is 3D and must be
superposed with another graph.
- ``aspect_ratio`` -- (default: 'automatic') aspect ratio of the plot;
the default value ('automatic') applies only for 2D plots; for
3D plots, the default value is ``1`` instead.
OUTPUT:
- a graphic object, either an instance of
:class:`~sage.plot.graphics.Graphics` for a 2D plot (i.e. based on
2 coordinates of ``chart``) or an instance of
:class:`~sage.plot.plot3d.base.Graphics3d` for a 3D plot (i.e.
based on 3 coordinates of ``chart``)
EXAMPLES:
Plot of the lemniscate of Gerono::
sage: R2 = Manifold(2, 'R^2')
sage: X.<x,y> = R2.chart()
sage: R.<t> = RealLine()
sage: c = R2.curve([sin(t), sin(2*t)/2], (t, 0, 2*pi), name='c')
sage: c.plot() # 2D plot
Graphics object consisting of 1 graphics primitive
Plot for a subinterval of the curve's domain::
sage: c.plot(prange=(0,pi))
Graphics object consisting of 1 graphics primitive
Plot with various options::
sage: c.plot(color='green', style=':', thickness=3, aspect_ratio=1)
Graphics object consisting of 1 graphics primitive
Plot via a mapping to another manifold: loxodrome of a sphere viewed
in `\RR^3`::
sage: S2 = Manifold(2, 'S^2')
sage: U = S2.open_subset('U')
sage: XS.<th,ph> = U.chart(r'th:(0,pi):\theta ph:(0,2*pi):\phi')
sage: R3 = Manifold(3, 'R^3')
sage: X3.<x,y,z> = R3.chart()
sage: F = S2.diff_mapping(R3, {(XS, X3): [sin(th)*cos(ph),
....: sin(th)*sin(ph), cos(th)]}, name='F')
sage: F.display()
F: S^2 --> R^3
on U: (th, ph) |--> (x, y, z) = (cos(ph)*sin(th), sin(ph)*sin(th), cos(th))
sage: c = S2.curve([2*atan(exp(-t/10)), t], (t, -oo, +oo), name='c')
sage: graph_c = c.plot(mapping=F, max_value=40,
....: plot_points=200, thickness=2, label_axes=False) # 3D plot
sage: graph_S2 = XS.plot(X3, mapping=F, nb_values=11, color='black') # plot of the sphere
sage: show(graph_c + graph_S2) # the loxodrome + the sphere
Example of use of the argument ``parameters``: we define a curve with
some symbolic parameters ``a`` and ``b``::
sage: a, b = var('a b')
sage: c = R2.curve([a*cos(t) + b, a*sin(t)], (t, 0, 2*pi), name='c')
To make a plot, we set spectific values for ``a`` and ``b`` by means
of the Python dictionary ``parameters``::
sage: c.plot(parameters={a: 2, b: -3}, aspect_ratio=1)
Graphics object consisting of 1 graphics primitive
"""
from sage.rings.infinity import Infinity
from sage.misc.functional import numerical_approx
from sage.plot.graphics import Graphics
from sage.plot.line import line
from sage.geometry.manifolds.chart import Chart
from sage.geometry.manifolds.utilities import set_axes_labels
#
# The "effective" curve to be plotted
#
if mapping is None:
eff_curve = self
else:
eff_curve = mapping.restrict(self.codomain()) * self
#
# The chart w.r.t. which the curve is plotted
#
if chart is None:
chart = eff_curve._codomain.default_chart()
elif not isinstance(chart, Chart):
raise TypeError("{} is not a chart".format(chart))
#
# Coordinates of the above chart w.r.t. which the curve is plotted
#
if ambient_coords is None:
ambient_coords = chart[:] # all chart coordinates are used
n_pc = len(ambient_coords)
if n_pc != 2 and n_pc !=3:
raise ValueError("The number of coordinates involved in the " +
"plot must be either 2 or 3, not {}".format(n_pc))
ind_pc = [chart[:].index(pc) for pc in ambient_coords] # indices of plot
# coordinates
#
# Parameter range for the plot
#
if prange is None:
prange = (self._domain.lower_bound(), self._domain.upper_bound())
elif not isinstance(prange, (tuple, list)):
raise TypeError("{} is neither a tuple nor a list".format(prange))
elif len(prange) != 2:
raise ValueError("the argument prange must be a tuple/list " +
"of 2 elements")
tmin = prange[0]
tmax = prange[1]
if tmin == -Infinity:
tmin = -max_value
elif not include_end_point[0]:
tmin = tmin + end_point_offset[0]
if tmax == Infinity:
tmax = max_value
elif not include_end_point[1]:
tmax = tmax - end_point_offset[1]
tmin = numerical_approx(tmin)
tmax = numerical_approx(tmax)
#
# The coordinate expression of the effective curve
#
canon_chart = self._domain.canonical_chart()
transf = None
for chart_pair in eff_curve._coord_expression:
if chart_pair == (canon_chart, chart):
transf = eff_curve._coord_expression[chart_pair]
break
else:
# Search for a subchart
for chart_pair in eff_curve._coord_expression:
for schart in chart._subcharts:
if chart_pair == (canon_chart, schart):
transf = eff_curve._coord_expression[chart_pair]
if transf is None:
raise ValueError("No expression has been found for " +
"{} in terms of {}".format(self, format))
#
# List of points for the plot curve
#
plot_curve = []
dt = (tmax - tmin) / (plot_points - 1)
t = tmin
if parameters is None:
for i in range(plot_points):
x = transf(t, simplify=False)
plot_curve.append( [numerical_approx(x[j]) for j in ind_pc] )
t += dt
else:
for i in range(plot_points):
x = transf(t, simplify=False)
plot_curve.append(
[numerical_approx( x[j].substitute(parameters) )
for j in ind_pc] )
t += dt
#
# The plot
#
resu = Graphics()
resu += line(plot_curve, color=color, linestyle=style,
thickness=thickness)
if n_pc==2: # 2D graphic
resu.set_aspect_ratio(aspect_ratio)
if label_axes:
# We update the dictionary _extra_kwds (options to be passed
# to show()), instead of using the method
# Graphics.axes_labels() since the latter is not robust w.r.t.
# graph addition
resu._extra_kwds['axes_labels'] = [r'$'+latex(pc)+r'$'
for pc in ambient_coords]
else: # 3D graphic
if aspect_ratio == 'automatic':
aspect_ratio = 1
resu.aspect_ratio(aspect_ratio)
if label_axes:
labels = [str(pc) for pc in ambient_coords]
resu = set_axes_labels(resu, *labels)
return resu
def plot(self,
chart=None,
ambient_coords=None,
mapping=None,
prange=None,
include_end_point=(True, True),
end_point_offset=(0.001, 0.001),
parameters=None,
color='red',
style='-',
label_axes=True,
**kwds):
r"""
Plot the current curve in a Cartesian graph based on the
coordinates of some ambient chart.
The curve is drawn in terms of two (2D graphics) or three (3D graphics)
coordinates of a given chart, called hereafter the *ambient chart*.
The ambient chart's domain must overlap with the curve's codomain or
with the codomain of the composite curve `\Phi\circ c`, where `c` is
the current curve and `\Phi` some manifold differential map (argument
``mapping`` below).
INPUT:
- ``chart`` -- (default: ``None``) the ambient chart (see above);
if ``None``, the default chart of the codomain of the curve (or of
the curve composed with `\Phi`) is used
- ``ambient_coords`` -- (default: ``None``) tuple containing the 2
or 3 coordinates of the ambient chart in terms of which the plot
is performed; if ``None``, all the coordinates of the ambient chart
are considered
- ``mapping`` -- (default: ``None``) differentiable mapping `\Phi`
(instance of
:class:`~sage.manifolds.differentiable.diff_map.DiffMap`)
providing the link between the curve and the ambient chart ``chart``
(cf. above); if ``None``, the ambient chart is supposed to be defined
on the codomain of the curve.
- ``prange`` -- (default: ``None``) range of the curve parameter for
the plot; if ``None``, the entire parameter range declared during the
curve construction is considered (with -Infinity
replaced by ``-max_range`` and +Infinity by ``max_range``)
- ``include_end_point`` -- (default: ``(True, True)``) determines
whether the end points of ``prange`` are included in the plot
- ``end_point_offset`` -- (default: ``(0.001, 0.001)``) offsets from
the end points when they are not included in the plot: if
``include_end_point[0] == False``, the minimal value of the curve
parameter used for the plot is ``prange[0] + end_point_offset[0]``,
while if ``include_end_point[1] == False``, the maximal value is
``prange[1] - end_point_offset[1]``.
- ``max_range`` -- (default: 8) numerical value substituted to
+Infinity if the latter is the upper bound of the parameter range;
similarly ``-max_range`` is the numerical valued substituted for
-Infinity
- ``parameters`` -- (default: ``None``) dictionary giving the numerical
values of the parameters that may appear in the coordinate expression
of the curve
- ``color`` -- (default: 'red') color of the drawn curve
- ``style`` -- (default: '-') color of the drawn curve; NB: ``style``
is effective only for 2D plots
- ``thickness`` -- (default: 1) thickness of the drawn curve
- ``plot_points`` -- (default: 75) number of points to plot the curve
- ``label_axes`` -- (default: ``True``) boolean determining whether the
labels of the coordinate axes of ``chart`` shall be added to the
graph; can be set to ``False`` if the graph is 3D and must be
superposed with another graph.
- ``aspect_ratio`` -- (default: ``'automatic'``) aspect ratio of the
plot; the default value (``'automatic'``) applies only for 2D plots;
for 3D plots, the default value is ``1`` instead
OUTPUT:
- a graphic object, either an instance of
:class:`~sage.plot.graphics.Graphics` for a 2D plot (i.e. based on
2 coordinates of ``chart``) or an instance of
:class:`~sage.plot.plot3d.base.Graphics3d` for a 3D plot (i.e.
based on 3 coordinates of ``chart``)
EXAMPLES:
Plot of the lemniscate of Gerono::
sage: R2 = Manifold(2, 'R^2')
sage: X.<x,y> = R2.chart()
sage: R.<t> = RealLine()
sage: c = R2.curve([sin(t), sin(2*t)/2], (t, 0, 2*pi), name='c')
sage: c.plot() # 2D plot
Graphics object consisting of 1 graphics primitive
.. PLOT::
R2 = Manifold(2, 'R^2')
X = R2.chart('x y')
t = RealLine().canonical_coordinate()
c = R2.curve([sin(t), sin(2*t)/2], (t, 0, 2*pi), name='c')
g = c.plot()
sphinx_plot(g)
Plot for a subinterval of the curve's domain::
sage: c.plot(prange=(0,pi))
Graphics object consisting of 1 graphics primitive
.. PLOT::
R2 = Manifold(2, 'R^2')
X = R2.chart('x y')
t = RealLine().canonical_coordinate()
c = R2.curve([sin(t), sin(2*t)/2], (t, 0, 2*pi), name='c')
g = c.plot(prange=(0,pi))
sphinx_plot(g)
Plot with various options::
sage: c.plot(color='green', style=':', thickness=3, aspect_ratio=1)
Graphics object consisting of 1 graphics primitive
.. PLOT::
R2 = Manifold(2, 'R^2')
X = R2.chart('x y')
t = RealLine().canonical_coordinate()
c = R2.curve([sin(t), sin(2*t)/2], (t, 0, 2*pi), name='c')
g = c.plot(color='green', style=':', thickness=3, aspect_ratio=1)
sphinx_plot(g)
Plot via a mapping to another manifold: loxodrome of a sphere viewed
in `\RR^3`::
sage: S2 = Manifold(2, 'S^2')
sage: U = S2.open_subset('U')
sage: XS.<th,ph> = U.chart(r'th:(0,pi):\theta ph:(0,2*pi):\phi')
sage: R3 = Manifold(3, 'R^3')
sage: X3.<x,y,z> = R3.chart()
sage: F = S2.diff_map(R3, {(XS, X3): [sin(th)*cos(ph),
....: sin(th)*sin(ph), cos(th)]}, name='F')
sage: F.display()
F: S^2 --> R^3
on U: (th, ph) |--> (x, y, z) = (cos(ph)*sin(th), sin(ph)*sin(th), cos(th))
sage: c = S2.curve([2*atan(exp(-t/10)), t], (t, -oo, +oo), name='c')
sage: graph_c = c.plot(mapping=F, max_range=40,
....: plot_points=200, thickness=2, label_axes=False) # 3D plot
sage: graph_S2 = XS.plot(X3, mapping=F, number_values=11, color='black') # plot of the sphere
sage: show(graph_c + graph_S2) # the loxodrome + the sphere
.. PLOT::
S2 = Manifold(2, 'S^2')
U = S2.open_subset('U')
XS = U.chart(r'th:(0,pi):\theta ph:(0,2*pi):\phi')
th, ph = XS[:]
R3 = Manifold(3, 'R^3')
X3 = R3.chart('x y z')
F = S2.diff_map(R3, {(XS, X3): [sin(th)*cos(ph), sin(th)*sin(ph),
cos(th)]}, name='F')
t = RealLine().canonical_coordinate()
c = S2.curve([2*atan(exp(-t/10)), t], (t, -oo, +oo), name='c')
graph_c = c.plot(mapping=F, max_range=40, plot_points=200,
thickness=2, label_axes=False)
graph_S2 = XS.plot(X3, mapping=F, number_values=11, color='black')
sphinx_plot(graph_c + graph_S2)
Example of use of the argument ``parameters``: we define a curve with
some symbolic parameters ``a`` and ``b``::
sage: a, b = var('a b')
sage: c = R2.curve([a*cos(t) + b, a*sin(t)], (t, 0, 2*pi), name='c')
To make a plot, we set spectific values for ``a`` and ``b`` by means
of the Python dictionary ``parameters``::
sage: c.plot(parameters={a: 2, b: -3}, aspect_ratio=1)
Graphics object consisting of 1 graphics primitive
.. PLOT::
R2 = Manifold(2, 'R^2')
X = R2.chart('x y')
t = RealLine().canonical_coordinate()
a, b = var('a b')
c = R2.curve([a*cos(t) + b, a*sin(t)], (t, 0, 2*pi), name='c')
g = c.plot(parameters={a: 2, b: -3}, aspect_ratio=1)
sphinx_plot(g)
"""
from sage.rings.infinity import Infinity
from sage.misc.functional import numerical_approx
from sage.plot.graphics import Graphics
from sage.plot.line import line
from sage.manifolds.chart import RealChart
from sage.manifolds.utilities import set_axes_labels
#
# Get the @options from kwds
#
thickness = kwds.pop('thickness')
plot_points = kwds.pop('plot_points')
max_range = kwds.pop('max_range')
aspect_ratio = kwds.pop('aspect_ratio')
#
# The "effective" curve to be plotted
#
if mapping is None:
eff_curve = self
else:
eff_curve = mapping.restrict(self.codomain()) * self
#
# The chart w.r.t. which the curve is plotted
#
if chart is None:
chart = eff_curve._codomain.default_chart()
elif not isinstance(chart, RealChart):
raise TypeError("{} is not a real chart".format(chart))
#
# Coordinates of the above chart w.r.t. which the curve is plotted
#
if ambient_coords is None:
ambient_coords = chart[:] # all chart coordinates are used
n_pc = len(ambient_coords)
if n_pc != 2 and n_pc != 3:
raise ValueError("the number of coordinates involved in the " +
"plot must be either 2 or 3, not {}".format(n_pc))
# indices of plot coordinates
ind_pc = [chart[:].index(pc) for pc in ambient_coords]
#
# Parameter range for the plot
#
if prange is None:
prange = (self._domain.lower_bound(), self._domain.upper_bound())
elif not isinstance(prange, (tuple, list)):
raise TypeError("{} is neither a tuple nor a list".format(prange))
elif len(prange) != 2:
raise ValueError("the argument prange must be a tuple/list " +
"of 2 elements")
tmin = prange[0]
tmax = prange[1]
if tmin == -Infinity:
tmin = -max_range
elif not include_end_point[0]:
tmin = tmin + end_point_offset[0]
if tmax == Infinity:
tmax = max_range
elif not include_end_point[1]:
tmax = tmax - end_point_offset[1]
tmin = numerical_approx(tmin)
tmax = numerical_approx(tmax)
#
# The coordinate expression of the effective curve
#
canon_chart = self._domain.canonical_chart()
transf = None
for chart_pair in eff_curve._coord_expression:
if chart_pair == (canon_chart, chart):
transf = eff_curve._coord_expression[chart_pair]
break
else:
# Search for a subchart
for chart_pair in eff_curve._coord_expression:
for schart in chart._subcharts:
if chart_pair == (canon_chart, schart):
transf = eff_curve._coord_expression[chart_pair]
if transf is None:
raise ValueError("No expression has been found for " +
"{} in terms of {}".format(self, chart))
#
# List of points for the plot curve
#
plot_curve = []
dt = (tmax - tmin) / (plot_points - 1)
t = tmin
if parameters is None:
for i in range(plot_points):
x = transf(t, simplify=False)
plot_curve.append([numerical_approx(x[j]) for j in ind_pc])
t += dt
else:
for i in range(plot_points):
x = transf(t, simplify=False)
plot_curve.append([
numerical_approx(x[j].substitute(parameters))
for j in ind_pc
])
t += dt
#
# The plot
#
resu = Graphics()
resu += line(plot_curve,
color=color,
linestyle=style,
thickness=thickness)
if n_pc == 2: # 2D graphic
resu.set_aspect_ratio(aspect_ratio)
if label_axes:
# We update the dictionary _extra_kwds (options to be passed
# to show()), instead of using the method
# Graphics.axes_labels() since the latter is not robust w.r.t.
# graph addition
resu._extra_kwds['axes_labels'] = [
r'$' + latex(pc) + r'$' for pc in ambient_coords
]
else: # 3D graphic
if aspect_ratio == 'automatic':
aspect_ratio = 1
resu.aspect_ratio(aspect_ratio)
if label_axes:
labels = [str(pc) for pc in ambient_coords]
resu = set_axes_labels(resu, *labels)
return resu
def finalize(self, G):
r"""
Finalize a root system plot.
INPUT:
- ``G`` -- a root system plot or ``0``
This sets the aspect ratio to 1 and remove the axes. This
should be called by all the user-level plotting methods of
root systems. This will become mostly obsolete when
customization options won't be lost anymore upon addition of
graphics objects and there will be a proper empty object for
2D and 3D plots.
EXAMPLES::
sage: L = RootSystem(["B",2,1]).ambient_space()
sage: options = L.plot_parse_options()
sage: p = L.plot_roots(plot_options=options)
sage: p += L.plot_coroots(plot_options=options)
sage: p.axes()
True
sage: p = options.finalize(p)
sage: p.axes()
False
sage: p.aspect_ratio()
1.0
sage: options = L.plot_parse_options(affine=False)
sage: p = L.plot_roots(plot_options=options)
sage: p += point([[1,1,0]])
sage: p = options.finalize(p)
sage: p.aspect_ratio()
[1.0, 1.0, 1.0]
If the input is ``0``, this returns an empty graphics object::
sage: type(options.finalize(0))
<class 'sage.plot.plot3d.base.Graphics3dGroup'>
sage: options = L.plot_parse_options()
sage: type(options.finalize(0))
<class 'sage.plot.graphics.Graphics'>
sage: list(options.finalize(0))
[]
"""
from sage.plot.graphics import Graphics
if self.dimension == 2:
if G == 0:
G = Graphics()
G.set_aspect_ratio(1)
# TODO: make this customizable
G.axes(False)
elif self.dimension == 3:
if G == 0:
from sage.plot.plot3d.base import Graphics3dGroup
G = Graphics3dGroup()
G.aspect_ratio(1)
# TODO: Configuration axes
return G
def finalize(self, G):
r"""
Finalize a root system plot.
INPUT:
- ``G`` -- a root system plot or ``0``
This sets the aspect ratio to 1 and remove the axes. This
should be called by all the user-level plotting methods of
root systems. This will become mostly obsolete when
customization options won't be lost anymore upon addition of
graphics objects and there will be a proper empty object for
2D and 3D plots.
EXAMPLES::
sage: L = RootSystem(["B",2,1]).ambient_space()
sage: options = L.plot_parse_options()
sage: p = L.plot_roots(plot_options=options)
sage: p += L.plot_coroots(plot_options=options)
sage: p.axes()
True
sage: p = options.finalize(p)
sage: p.axes()
False
sage: p.aspect_ratio()
1.0
sage: options = L.plot_parse_options(affine=False)
sage: p = L.plot_roots(plot_options=options)
sage: p += point([[1,1,0]])
sage: p = options.finalize(p)
sage: p.aspect_ratio()
[1.0, 1.0, 1.0]
If the input is ``0``, this returns an empty graphics object::
sage: type(options.finalize(0))
<class 'sage.plot.plot3d.base.Graphics3dGroup'>
sage: options = L.plot_parse_options()
sage: type(options.finalize(0))
<class 'sage.plot.graphics.Graphics'>
sage: list(options.finalize(0))
[]
"""
from sage.plot.graphics import Graphics
if self.dimension == 2:
if G == 0:
G = Graphics()
G.set_aspect_ratio(1)
# TODO: make this customizable
G.axes(False)
elif self.dimension == 3:
if G == 0:
from sage.plot.plot3d.base import Graphics3dGroup
G = Graphics3dGroup()
G.aspect_ratio(1)
# TODO: Configuration axes
return G
def plot(self, **kwds):
r"""
Plot the initial triangulation associated to ``self``.
INPUT:
- ``radius`` - the radius of the disk; by default the length of
the circle is the number of vertices
- ``points_color`` - the color of the vertices; default 'black'
- ``points_size`` - the size of the vertices; default 7
- ``triangulation_color`` - the color of the arcs; default 'black'
- ``triangulation_thickness`` - the thickness of the arcs; default 0.5
- ``shading_color`` - the color of the shading used on neuter
intervals; default 'lightgray'
- ``reflections_color`` - the color of the reflection axes; default
'blue'
- ``reflections_thickness`` - the thickness of the reflection axes;
default 1
EXAMPLES::
sage: Y = SineGordonYsystem('A',(6,4,3))
sage: Y.plot() # long time 2s
Graphics object consisting of 219 graphics primitives
"""
# Set up plotting options
if 'radius' in kwds:
radius = kwds['radius']
else:
radius = ceil(self.r() / (2 * pi))
points_opts = {}
if 'points_color' in kwds:
points_opts['color'] = kwds['points_color']
else:
points_opts['color'] = 'black'
if 'points_size' in kwds:
points_opts['size'] = kwds['points_size']
else:
points_opts['size'] = 7
triangulation_opts = {}
if 'triangulation_color' in kwds:
triangulation_opts['color'] = kwds['triangulation_color']
else:
triangulation_opts['color'] = 'black'
if 'triangulation_thickness' in kwds:
triangulation_opts['thickness'] = kwds['triangulation_thickness']
else:
triangulation_opts['thickness'] = 0.5
shading_opts = {}
if 'shading_color' in kwds:
shading_opts['color'] = kwds['shading_color']
else:
shading_opts['color'] = 'lightgray'
reflections_opts = {}
if 'reflections_color' in kwds:
reflections_opts['color'] = kwds['reflections_color']
else:
reflections_opts['color'] = 'blue'
if 'reflections_thickness' in kwds:
reflections_opts['thickness'] = kwds['reflections_thickness']
else:
reflections_opts['thickness'] = 1
# Helper functions
def triangle(x):
(a, b) = sorted(x[:2])
for p in self.vertices():
if (p, a) in self.triangulation() or (a, p) in self.triangulation():
if (p, b) in self.triangulation() or (b, p) in self.triangulation():
if p < a or p > b:
return sorted((a, b, p))
def plot_arc(radius, p, q, **opts):
# TODO: THIS SHOULD USE THE EXISTING PLOT OF ARCS!
# plot the arc from p to q differently depending on the type of self
p = ZZ(p)
q = ZZ(q)
t = var('t')
if p - q in [1, -1]:
def f(t):
return (radius * cos(t), radius * sin(t))
(p, q) = sorted([p, q])
angle_p = vertex_to_angle(p)
angle_q = vertex_to_angle(q)
return parametric_plot(f(t), (t, angle_q, angle_p), **opts)
if self.type() == 'A':
angle_p = vertex_to_angle(p)
angle_q = vertex_to_angle(q)
if angle_p < angle_q:
angle_p += 2 * pi
internal_angle = angle_p - angle_q
if internal_angle > pi:
(angle_p, angle_q) = (angle_q + 2 * pi, angle_p)
internal_angle = angle_p - angle_q
angle_center = (angle_p+angle_q) / 2
hypotenuse = radius / cos(internal_angle / 2)
radius_arc = hypotenuse * sin(internal_angle / 2)
center = (hypotenuse * cos(angle_center),
hypotenuse * sin(angle_center))
center_angle_p = angle_p + pi / 2
center_angle_q = angle_q + 3 * pi / 2
def f(t):
return (radius_arc * cos(t) + center[0],
radius_arc * sin(t) + center[1])
return parametric_plot(f(t), (t, center_angle_p,
center_angle_q), **opts)
elif self.type() == 'D':
if p >= q:
q += self.r()
px = -2 * pi * p / self.r() + pi / 2
qx = -2 * pi * q / self.r() + pi / 2
arc_radius = (px - qx) / 2
arc_center = qx + arc_radius
def f(t):
return exp(I * ((cos(t) + I * sin(t)) *
arc_radius + arc_center)) * radius
return parametric_plot((real_part(f(t)), imag_part(f(t))),
(t, 0, pi), **opts)
def vertex_to_angle(v):
# v==0 corresponds to pi/2
return -2 * pi * RR(v) / self.r() + 5 * pi / 2
# Begin plotting
P = Graphics()
# Shade neuter intervals
neuter_intervals = [x for x in flatten(self.intervals()[:-1],
max_level=1)
if x[2] in ["NR", "NL"]]
shaded_triangles = map(triangle, neuter_intervals)
for (p, q, r) in shaded_triangles:
points = list(plot_arc(radius, p, q)[0])
points += list(plot_arc(radius, q, r)[0])
points += list(reversed(plot_arc(radius, p, r)[0]))
P += polygon2d(points, **shading_opts)
# Disk boundary
P += circle((0, 0), radius, **triangulation_opts)
# Triangulation
for (p, q) in self.triangulation():
P += plot_arc(radius, p, q, **triangulation_opts)
if self.type() == 'D':
s = radius / 50.0
P += polygon2d([(s, 5 * s), (s, 7 * s),
(3 * s, 5 * s), (3 * s, 7 * s)],
color=triangulation_opts['color'])
P += bezier_path([[(0, 0), (2 * s, 1 * s), (2 * s, 6 * s)],
[(2 * s, 10 * s), (s, 20 * s)],
[(0, 30 * s), (0, radius)]],
**triangulation_opts)
P += bezier_path([[(0, 0), (-2 * s, 1 * s), (-2 * s, 6 * s)],
[(-2 * s, 10 * s), (-s, 20 * s)],
[(0, 30 * s), (0, radius)]],
**triangulation_opts)
P += point((0, 0), zorder=len(P), **points_opts)
# Vertices
v_points = {x: (radius * cos(vertex_to_angle(x)),
radius * sin(vertex_to_angle(x)))
for x in self.vertices()}
for v in v_points:
P += point(v_points[v], zorder=len(P), **points_opts)
# Reflection axes
P += line([(0, 1.1 * radius), (0, -1.1 * radius)],
zorder=len(P), **reflections_opts)
axis_angle = vertex_to_angle(-0.5 * (self.rk() + (1, 1))[1])
(a, b) = (1.1 * radius * cos(axis_angle),
1.1 * radius * sin(axis_angle))
P += line([(a, b), (-a, -b)], zorder=len(P), **reflections_opts)
# Wrap up
P.set_aspect_ratio(1)
P.axes(False)
return P
def plot(self, **kwds):
r"""
Plot the initial triangulation associated to ``self``.
INPUT:
- ``radius`` - the radius of the disk; by default the length of
the circle is the number of vertices
- ``points_color`` - the color of the vertices; default 'black'
- ``points_size`` - the size of the vertices; default 7
- ``triangulation_color`` - the color of the arcs; default 'black'
- ``triangulation_thickness`` - the thickness of the arcs; default 0.5
- ``shading_color`` - the color of the shading used on neuter
intervals; default 'lightgray'
- ``reflections_color`` - the color of the reflection axes; default
'blue'
- ``reflections_thickness`` - the thickness of the reflection axes;
default 1
EXAMPLES::
sage: Y = SineGordonYsystem('A',(6,4,3));
sage: Y.plot() # not tested
"""
# Set up plotting options
if 'radius' in kwds:
radius = kwds['radius']
else:
radius = ceil(self.r() / (2 * pi))
points_opts = {}
if 'points_color' in kwds:
points_opts['color'] = kwds['points_color']
else:
points_opts['color'] = 'black'
if 'points_size' in kwds:
points_opts['size'] = kwds['points_size']
else:
points_opts['size'] = 7
triangulation_opts = {}
if 'triangulation_color' in kwds:
triangulation_opts['color'] = kwds['triangulation_color']
else:
triangulation_opts['color'] = 'black'
if 'triangulation_thickness' in kwds:
triangulation_opts['thickness'] = kwds['triangulation_thickness']
else:
triangulation_opts['thickness'] = 0.5
shading_opts = {}
if 'shading_color' in kwds:
shading_opts['color'] = kwds['shading_color']
else:
shading_opts['color'] = 'lightgray'
reflections_opts = {}
if 'reflections_color' in kwds:
reflections_opts['color'] = kwds['reflections_color']
else:
reflections_opts['color'] = 'blue'
if 'reflections_thickness' in kwds:
reflections_opts['thickness'] = kwds['reflections_thickness']
else:
reflections_opts['thickness'] = 1
# Helper functions
def triangle(x):
(a, b) = sorted(x[:2])
for p in self.vertices():
if (p, a) in self.triangulation() or (a, p) in self.triangulation():
if (p, b) in self.triangulation() or (b, p) in self.triangulation():
if p < a or p > b:
return sorted((a, b, p))
def plot_arc(radius, p, q, **opts):
# plot the arc from p to q differently depending on the type of self
p = ZZ(p)
q = ZZ(q)
t = var('t')
if p - q in [1, -1]:
def f(t):
return (radius * cos(t), radius * sin(t))
(p, q) = sorted([p, q])
angle_p = vertex_to_angle(p)
angle_q = vertex_to_angle(q)
return parametric_plot(f(t), (t, angle_q, angle_p), **opts)
if self.type() == 'A':
angle_p = vertex_to_angle(p)
angle_q = vertex_to_angle(q)
if angle_p < angle_q:
angle_p += 2 * pi
internal_angle = angle_p - angle_q
if internal_angle > pi:
(angle_p, angle_q) = (angle_q + 2 * pi, angle_p)
internal_angle = angle_p - angle_q
angle_center = (angle_p+angle_q) / 2
hypotenuse = radius / cos(internal_angle / 2)
radius_arc = hypotenuse * sin(internal_angle / 2)
center = (hypotenuse * cos(angle_center),
hypotenuse * sin(angle_center))
center_angle_p = angle_p + pi / 2
center_angle_q = angle_q + 3 * pi / 2
def f(t):
return (radius_arc * cos(t) + center[0],
radius_arc * sin(t) + center[1])
return parametric_plot(f(t), (t, center_angle_p,
center_angle_q), **opts)
elif self.type() == 'D':
if p >= q:
q += self.r()
px = -2 * pi * p / self.r() + pi / 2
qx = -2 * pi * q / self.r() + pi / 2
arc_radius = (px - qx) / 2
arc_center = qx + arc_radius
def f(t):
return exp(I * ((cos(t) + I * sin(t)) *
arc_radius + arc_center)) * radius
return parametric_plot((real_part(f(t)), imag_part(f(t))),
(t, 0, pi), **opts)
def vertex_to_angle(v):
# v==0 corresponds to pi/2
return -2 * pi * RR(v) / self.r() + 5 * pi / 2
# Begin plotting
P = Graphics()
# Shade neuter intervals
neuter_intervals = [x for x in flatten(self.intervals()[:-1],
max_level=1)
if x[2] in ["NR", "NL"]]
shaded_triangles = map(triangle, neuter_intervals)
for (p, q, r) in shaded_triangles:
points = list(plot_arc(radius, p, q)[0])
points += list(plot_arc(radius, q, r)[0])
points += list(reversed(plot_arc(radius, p, r)[0]))
P += polygon2d(points, **shading_opts)
# Disk boundary
P += circle((0, 0), radius, **triangulation_opts)
# Triangulation
for (p, q) in self.triangulation():
P += plot_arc(radius, p, q, **triangulation_opts)
if self.type() == 'D':
s = radius / 50.0
P += polygon2d([(s, 5 * s), (s, 7 * s),
(3 * s, 5 * s), (3 * s, 7 * s)],
color=triangulation_opts['color'])
P += bezier_path([[(0, 0), (2 * s, 1 * s), (2 * s, 6 * s)],
[(2 * s, 10 * s), (s, 20 * s)],
[(0, 30 * s), (0, radius)]],
**triangulation_opts)
P += bezier_path([[(0, 0), (-2 * s, 1 * s), (-2 * s, 6 * s)],
[(-2 * s, 10 * s), (-s, 20 * s)],
[(0, 30 * s), (0, radius)]],
**triangulation_opts)
P += point((0, 0), zorder=len(P), **points_opts)
# Vertices
v_points = {x: (radius * cos(vertex_to_angle(x)),
radius * sin(vertex_to_angle(x)))
for x in self.vertices()}
for v in v_points:
P += point(v_points[v], zorder=len(P), **points_opts)
# Reflection axes
P += line([(0, 1.1 * radius), (0, -1.1 * radius)],
zorder=len(P), **reflections_opts)
axis_angle = vertex_to_angle(-0.5 * (self.rk() + (1, 1))[1])
(a, b) = (1.1 * radius * cos(axis_angle),
1.1 * radius * sin(axis_angle))
P += line([(a, b), (-a, -b)], zorder=len(P), **reflections_opts)
# Wrap up
P.set_aspect_ratio(1)
P.axes(False)
return P
def _graphics(self, plot_curve, ambient_coords, thickness=1,
aspect_ratio='automatic', color='red', style='-',
label_axes=True):
r"""
Plot a 2D or 3D curve in a Cartesian graph with axes labeled by
the ambient coordinates; it is invoked by the methods
:meth:`plot` of
:class:`~sage.manifolds.differentiable.curve.DifferentiableCurve`,
and its subclasses
(:class:`~sage.manifolds.differentiable.integrated_curve.IntegratedCurve`,
:class:`~sage.manifolds.differentiable.integrated_curve.IntegratedAutoparallelCurve`,
and
:class:`~sage.manifolds.differentiable.integrated_curve.IntegratedGeodesic`).
TESTS::
sage: M = Manifold(2, 'R^2')
sage: X.<x,y> = M.chart()
sage: R.<t> = RealLine()
sage: c = M.curve([cos(t), sin(t)], (t, 0, 2*pi), name='c')
sage: graph = c._graphics([[1,2], [3,4]], [x,y])
sage: graph._objects[0].xdata == [1,3]
True
sage: graph._objects[0].ydata == [2,4]
True
sage: graph._objects[0]._options['thickness'] == 1
True
sage: graph._extra_kwds['aspect_ratio'] == 'automatic'
True
sage: graph._objects[0]._options['rgbcolor'] == 'red'
True
sage: graph._objects[0]._options['linestyle'] == '-'
True
sage: l = [r'$'+latex(x)+r'$', r'$'+latex(y)+r'$']
sage: graph._extra_kwds['axes_labels'] == l
True
"""
from sage.plot.graphics import Graphics
from sage.plot.line import line
from sage.manifolds.utilities import set_axes_labels
#
# The plot
#
n_pc = len(ambient_coords)
resu = Graphics()
resu += line(plot_curve, color=color, linestyle=style,
thickness=thickness)
if n_pc == 2: # 2D graphic
resu.set_aspect_ratio(aspect_ratio)
if label_axes:
# We update the dictionary _extra_kwds (options to be passed
# to show()), instead of using the method
# Graphics.axes_labels() since the latter is not robust w.r.t.
# graph addition
resu._extra_kwds['axes_labels'] = [r'$'+latex(pc)+r'$'
for pc in ambient_coords]
else: # 3D graphic
if aspect_ratio == 'automatic':
aspect_ratio = 1
resu.aspect_ratio(aspect_ratio)
if label_axes:
labels = [str(pc) for pc in ambient_coords]
resu = set_axes_labels(resu, *labels)
return resu
def plot_cluster_fan_stereographically(self,
northsign=1,
north=None,
right=None,
colors=None,
d_vectors=False):
from sage.plot.graphics import Graphics
from sage.plot.point import point
from sage.misc.flatten import flatten
from sage.plot.line import line
from sage.misc.functional import norm
if self.rk != 3:
raise ValueError("Can only stereographically project fans in 3d.")
if not self.is_finite() and self._depth == infinity:
raise ValueError(
"For infinite algebras you must specify the depth.")
if north == None:
if self.is_affine():
north = vector(self.delta())
else:
north = vector((-1, -1, -1))
if right == None:
if self.is_affine():
right = vector(self.gamma())
else:
right = vector((1, 0, 0))
if colors == None:
colors = dict([(0, 'red'), (1, 'green'), (2, 'blue'), (3, 'cyan'),
(4, 'yellow')])
G = Graphics()
roots = list(self.g_vectors())
compatible = []
while roots:
x = roots.pop()
if x in self.initial_cluster() and d_vectors:
x1 = -self.simple_roots()[list(
self.initial_cluster()).index(x)]
else:
x1 = x
for y in roots:
if self.compatibility_degree(x, y) == 0:
if y in self.initial_cluster() and d_vectors:
y1 = -self.simple_roots()[list(
self.initial_cluster()).index(y)]
else:
y1 = y
compatible.append((x1, y1))
for (u, v) in compatible:
G += _stereo_arc(vector(u),
vector(v),
vector(u + v),
north=northsign * north,
right=right,
thickness=0.5,
color='black')
for i in range(3):
orbit = self.ith_orbit(i)
if d_vectors:
orbit[0] = -self.simple_roots()[list(
self.initial_cluster()).index(orbit[0])]
for j in orbit:
G += point(_stereo_coordinates(vector(orbit[j]),
north=northsign * north,
right=right),
color=colors[i],
zorder=len(G))
if self.is_affine():
tube_vectors = map(vector, flatten(self.affine_tubes()))
for v in tube_vectors:
G += point(_stereo_coordinates(v,
north=northsign * north,
right=right),
color=colors[3],
zorder=len(G))
if north != vector(self.delta()):
G += _stereo_arc(tube_vectors[0],
tube_vectors[1],
vector(self.delta()),
north=northsign * north,
right=right,
thickness=2,
color=colors[4],
zorder=0)
else:
# FIXME: refactor this before publishing
tube_projections = [
_stereo_coordinates(v,
north=northsign * north,
right=right) for v in tube_vectors
]
t = min(
(G.get_minmax_data()['xmax'], G.get_minmax_data()['ymax']))
G += line([
tube_projections[0], tube_projections[0] + t *
(_normalize(tube_projections[0] - tube_projections[1]))
],
thickness=2,
color=colors[4],
zorder=0)
G += line([
tube_projections[1], tube_projections[1] + t *
(_normalize(tube_projections[1] - tube_projections[0]))
],
thickness=2,
color=colors[4],
zorder=0)
G.set_aspect_ratio(1)
G._show_axes = False
return G
