def addTriangles(self, x, y, triangles, legend, color, z, selectable,
alpha):
for parameter in (x, y, triangles, legend, color, z, selectable,
alpha):
assert parameter is not None
# 0 enables picking on filled triangle
picker = 0 if selectable else None
color = numpy.array(color, copy=False)
assert color.ndim == 2 and len(color) == len(x)
if color.dtype not in [numpy.float32, numpy.float]:
color = color.astype(numpy.float32) / 255.
collection = TriMesh(Triangulation(x, y, triangles),
label=legend,
alpha=alpha,
picker=picker,
zorder=z)
collection.set_color(color)
self.ax.add_collection(collection)
return collection
def tripcolor(ax, *args, **kwargs):
"""
Create a pseudocolor plot of an unstructured triangular grid.
The triangulation can be specified in one of two ways; either::
tripcolor(triangulation, ...)
where triangulation is a :class:`matplotlib.tri.Triangulation`
object, or
::
tripcolor(x, y, ...)
tripcolor(x, y, triangles, ...)
tripcolor(x, y, triangles=triangles, ...)
tripcolor(x, y, mask=mask, ...)
tripcolor(x, y, triangles, mask=mask, ...)
in which case a Triangulation object will be created. See
:class:`~matplotlib.tri.Triangulation` for a explanation of these
possibilities.
The next argument must be *C*, the array of color values, either
one per point in the triangulation if color values are defined at
points, or one per triangle in the triangulation if color values
are defined at triangles. If there are the same number of points
and triangles in the triangulation it is assumed that color
values are defined at points; to force the use of color values at
triangles use the kwarg *facecolors*=C instead of just *C*.
*shading* may be 'flat' (the default) or 'gouraud'. If *shading*
is 'flat' and C values are defined at points, the color values
used for each triangle are from the mean C of the triangle's
three points. If *shading* is 'gouraud' then color values must be
defined at points.
The remaining kwargs are the same as for
:meth:`~matplotlib.axes.Axes.pcolor`.
**Example:**
.. plot:: mpl_examples/pylab_examples/tripcolor_demo.py
"""
if not ax._hold:
ax.cla()
alpha = kwargs.pop('alpha', 1.0)
norm = kwargs.pop('norm', None)
cmap = kwargs.pop('cmap', None)
vmin = kwargs.pop('vmin', None)
vmax = kwargs.pop('vmax', None)
shading = kwargs.pop('shading', 'flat')
facecolors = kwargs.pop('facecolors', None)
if shading not in ['flat', 'gouraud']:
raise ValueError("shading must be one of ['flat', 'gouraud'] "
"not {0}".format(shading))
tri, args, kwargs = Triangulation.get_from_args_and_kwargs(*args, **kwargs)
# C is the colors array defined at either points or faces (i.e. triangles).
# If facecolors is None, C are defined at points.
# If facecolors is not None, C are defined at faces.
if facecolors is not None:
C = facecolors
else:
C = np.asarray(args[0])
# If there are a different number of points and triangles in the
# triangulation, can omit facecolors kwarg as it is obvious from
# length of C whether it refers to points or faces.
# Do not do this for gouraud shading.
if (facecolors is None and len(C) == len(tri.triangles) and
len(C) != len(tri.x) and shading != 'gouraud'):
facecolors = C
# Check length of C is OK.
if ((facecolors is None and len(C) != len(tri.x)) or
(facecolors is not None and len(C) != len(tri.triangles))):
raise ValueError('Length of color values array must be the same '
'as either the number of triangulation points '
'or triangles')
# Handling of linewidths, shading, edgecolors and antialiased as
# in Axes.pcolor
linewidths = (0.25,)
if 'linewidth' in kwargs:
kwargs['linewidths'] = kwargs.pop('linewidth')
kwargs.setdefault('linewidths', linewidths)
edgecolors = 'none'
if 'edgecolor' in kwargs:
kwargs['edgecolors'] = kwargs.pop('edgecolor')
ec = kwargs.setdefault('edgecolors', edgecolors)
if 'antialiased' in kwargs:
kwargs['antialiaseds'] = kwargs.pop('antialiased')
if 'antialiaseds' not in kwargs and ec.lower() == "none":
kwargs['antialiaseds'] = False
if shading == 'gouraud':
if facecolors is not None:
raise ValueError('Gouraud shading does not support the use '
'of facecolors kwarg')
if len(C) != len(tri.x):
raise ValueError('For gouraud shading, the length of color '
'values array must be the same as the '
'number of triangulation points')
collection = TriMesh(tri, **kwargs)
else:
# Vertices of triangles.
maskedTris = tri.get_masked_triangles()
verts = np.concatenate((tri.x[maskedTris][..., np.newaxis],
tri.y[maskedTris][..., np.newaxis]), axis=2)
# Color values.
if facecolors is None:
# One color per triangle, the mean of the 3 vertex color values.
C = C[maskedTris].mean(axis=1)
elif tri.mask is not None:
# Remove color values of masked triangles.
C = C.compress(1-tri.mask)
collection = PolyCollection(verts, **kwargs)
collection.set_alpha(alpha)
collection.set_array(C)
if norm is not None:
if not isinstance(norm, Normalize):
msg = "'norm' must be an instance of 'Normalize'"
raise ValueError(msg)
collection.set_cmap(cmap)
collection.set_norm(norm)
if vmin is not None or vmax is not None:
collection.set_clim(vmin, vmax)
else:
collection.autoscale_None()
ax.grid(False)
minx = tri.x.min()
maxx = tri.x.max()
miny = tri.y.min()
maxy = tri.y.max()
corners = (minx, miny), (maxx, maxy)
ax.update_datalim(corners)
ax.autoscale_view()
ax.add_collection(collection)
return collection
def plotColorView(
ax,
cortex,
data,
viewkey,
shaded=False,
shadowed=False,
cmap=plt.cm.coolwarm,
l_azimuth=0,
l_altitude=0,
lightingBias=0.2, # Light azimuth and altitude, and bias
zlim=None,
zthresh=None,
suptitle='',
viewlabel=False):
# ================= This part should be computed only once for all views, but this way it is easier...
if 'flat' not in viewkey:
vtx_L, tri_L = cortex['model_L'].agg_data()
vtx_R, tri_R = cortex['model_R'].agg_data()
else:
vtx_L, tri_L = cortex['flat_L'].agg_data()
vtx_R, tri_R = cortex['flat_R'].agg_data()
xL, yL, zL = vtx_L.T
xR, yR, zR = vtx_R.T
if 'map_L' in cortex or 'map_R' in cortex:
# if we are giving a mapping between regions and vertices, let's use it!
rm_L = cortex['map_L']
rm_R = cortex['map_R']
if viewkey in ['Lh-lateral', 'Lh-medial', 'L-superior']:
vvalues = computeVertexValues(vtx_L, rm_L, data['func_L'])
else:
vvalues = computeVertexValues(vtx_R, rm_R, data['func_R'])
else: # if not, it is because we were given the vertex-level values directly
if viewkey in ['Lh-lateral', 'Lh-medial', 'L-superior']:
vvalues = data['func_L']
else:
vvalues = data['func_R']
views = {
'Lh-lateral': Triangulation(-yL, zL,
tri_L), #tri[np.argsort(lh_ty)[::-1]]),
'Lh-medial': Triangulation(yL, zL,
tri_L[::-1]), #lh_tri[np.argsort(lh_ty)]),
'Rh-medial':
Triangulation(-yR, zR,
tri_R[::-1]), #rh_tri[np.argsort(rh_ty)[::-1]]),
'Rh-lateral': Triangulation(yR, zR,
tri_R), #rh_tri[np.argsort(rh_ty)]),
'L-superior': Triangulation(xL, yL, tri_L), #tri[np.argsort(tz)]),
'R-superior': Triangulation(xR, yR, tri_R), #tri[np.argsort(tz)]),
'L-flat': Triangulation(xL, yL, tri_L),
'R-flat': Triangulation(xR, yR, tri_R),
}
# ================= View-specific code...
v = views[viewkey]
if not viewlabel:
plt.axis('off')
if zthresh:
z = vvalues.copy() * (abs(vvalues) > zthresh)
# ================= Let's render it!
if not shadowed or 'flat' in viewkey:
if 'flat' in viewkey:
kwargs = {'shading': 'flat'} # No edgecolors...
else:
kwargs = {
'shading': 'gouraud'
} if shaded else {
'shading': 'flat',
'edgecolors': 'k',
'linewidth': 0.1
}
tc = ax.tripcolor(v, vvalues, cmap=cmap, **kwargs)
if zlim:
tc.set_clim(vmin=-zlim, vmax=zlim)
else: # =================
# Ok, we have a problem: tripcolor does not seem to tolerate vertex-defined colors, something we need
# for shadows. So let's do this "manually". Internally, I think tripcolor uses a TriMesh to render
# the mesh if gouraud is used, but somehow the later stages do not like the outcome (when doing plt.show()).
# So, we are going to set the colors up... manually! I hate this as much as you do! ;-)
colors = mapValues2Colors(vvalues, cmap) # Vertex colors
if viewkey in ['Lh-lateral', 'Lh-medial', 'L-superior']:
normals = computeVertexNormals(vtx_L, tri_L)
else:
normals = computeVertexNormals(vtx_R, tri_R)
# Create a light source object for light from
# azimuth (from north), elevation (from 0 elevation plane). Both in degrees.
light = LightSource(l_azimuth, l_altitude)
shaded = lightingBias + light.shade_normals(normals) * (1 -
lightingBias)
shadedColors = (colors[:, 0:3].T * shaded).T
collection = TriMesh(v)
collection.set_facecolor(shadedColors)
ax.add_collection(collection)
ax.autoscale_view()
# =================
ax.set_aspect('equal')
if suptitle:
ax.set_title(suptitle, fontsize=24)
if viewlabel:
plt.xlabel(viewkey)
def tripcolor(ax, *args, **kwargs):
"""
Create a pseudocolor plot of an unstructured triangular grid to
the :class:`~matplotlib.axes.Axes`.
The triangulation can be specified in one of two ways; either::
tripcolor(triangulation, ...)
where triangulation is a :class:`~matplotlib.tri.Triangulation`
object, or
::
tripcolor(x, y, ...)
tripcolor(x, y, triangles, ...)
tripcolor(x, y, triangles=triangles, ...)
tripcolor(x, y, mask=mask, ...)
tripcolor(x, y, triangles, mask=mask, ...)
in which case a Triangulation object will be created. See
:class:`~matplotlib.tri.Triangulation` for a explanation of these
possibilities.
The next argument must be *C*, the array of color values, one per
point in the triangulation.
*shading* may be 'flat', 'faceted' or 'gouraud'. If *shading* is
'flat' or 'faceted', the colors used for each triangle are from
the mean C of the triangle's three points.
The remaining kwargs are the same as for
:meth:`~matplotlib.axes.Axes.pcolor`.
**Example:**
.. plot:: mpl_examples/pylab_examples/tripcolor_demo.py
"""
if not ax._hold: ax.cla()
alpha = kwargs.pop('alpha', 1.0)
norm = kwargs.pop('norm', None)
cmap = kwargs.pop('cmap', None)
vmin = kwargs.pop('vmin', None)
vmax = kwargs.pop('vmax', None)
shading = kwargs.pop('shading', 'flat')
tri, args, kwargs = Triangulation.get_from_args_and_kwargs(*args, **kwargs)
x = tri.x
y = tri.y
triangles = tri.get_masked_triangles()
C = np.asarray(args[0])
if C.shape != x.shape:
raise ValueError('C array must have same length as triangulation x and'
' y arrays')
if shading == 'gouraud':
collection = TriMesh(tri, **kwargs)
else:
if shading == 'faceted':
edgecolors = (0,0,0,1),
linewidths = (0.25,)
else:
edgecolors = 'face'
linewidths = (1.0,)
kwargs.setdefault('edgecolors', edgecolors)
kwargs.setdefault('antialiaseds', (0,))
kwargs.setdefault('linewidths', linewidths)
# Vertices of triangles.
verts = np.concatenate((x[triangles][...,np.newaxis],
y[triangles][...,np.newaxis]), axis=2)
# Color values, one per triangle, mean of the 3 vertex color values.
C = C[triangles].mean(axis=1)
collection = PolyCollection(verts, **kwargs)
collection.set_alpha(alpha)
collection.set_array(C)
if norm is not None: assert(isinstance(norm, Normalize))
collection.set_cmap(cmap)
collection.set_norm(norm)
if vmin is not None or vmax is not None:
collection.set_clim(vmin, vmax)
else:
collection.autoscale_None()
ax.grid(False)
minx = tri.x.min()
maxx = tri.x.max()
miny = tri.y.min()
maxy = tri.y.max()
corners = (minx, miny), (maxx, maxy)
ax.update_datalim( corners)
ax.autoscale_view()
ax.add_collection(collection)
return collection
def tripcolor(ax, *args, **kwargs):
"""
Create a pseudocolor plot of an unstructured triangular grid.
The triangulation can be specified in one of two ways; either::
tripcolor(triangulation, ...)
where triangulation is a :class:`matplotlib.tri.Triangulation`
object, or
::
tripcolor(x, y, ...)
tripcolor(x, y, triangles, ...)
tripcolor(x, y, triangles=triangles, ...)
tripcolor(x, y, mask=mask, ...)
tripcolor(x, y, triangles, mask=mask, ...)
in which case a Triangulation object will be created. See
:class:`~matplotlib.tri.Triangulation` for a explanation of these
possibilities.
The next argument must be *C*, the array of color values, either
one per point in the triangulation if color values are defined at
points, or one per triangle in the triangulation if color values
are defined at triangles. If there are the same number of points
and triangles in the triangulation it is assumed that color
values are defined at points; to force the use of color values at
triangles use the kwarg *facecolors*=C instead of just *C*.
*shading* may be 'flat' (the default) or 'gouraud'. If *shading*
is 'flat' and C values are defined at points, the color values
used for each triangle are from the mean C of the triangle's
three points. If *shading* is 'gouraud' then color values must be
defined at points.
The remaining kwargs are the same as for
:meth:`~matplotlib.axes.Axes.pcolor`.
**Example:**
.. plot:: mpl_examples/pylab_examples/tripcolor_demo.py
"""
if not ax._hold:
ax.cla()
alpha = kwargs.pop('alpha', 1.0)
norm = kwargs.pop('norm', None)
cmap = kwargs.pop('cmap', None)
vmin = kwargs.pop('vmin', None)
vmax = kwargs.pop('vmax', None)
shading = kwargs.pop('shading', 'flat')
facecolors = kwargs.pop('facecolors', None)
if shading not in ['flat', 'gouraud']:
raise ValueError("shading must be one of ['flat', 'gouraud'] "
"not {0}".format(shading))
tri, args, kwargs = Triangulation.get_from_args_and_kwargs(*args, **kwargs)
# C is the colors array defined at either points or faces (i.e. triangles).
# If facecolors is None, C are defined at points.
# If facecolors is not None, C are defined at faces.
if facecolors is not None:
C = facecolors
else:
C = np.asarray(args[0])
# If there are a different number of points and triangles in the
# triangulation, can omit facecolors kwarg as it is obvious from
# length of C whether it refers to points or faces.
# Do not do this for gouraud shading.
if (facecolors is None and len(C) == len(tri.triangles) and
len(C) != len(tri.x) and shading != 'gouraud'):
facecolors = C
# Check length of C is OK.
if ((facecolors is None and len(C) != len(tri.x)) or
(facecolors is not None and len(C) != len(tri.triangles))):
raise ValueError('Length of color values array must be the same '
'as either the number of triangulation points '
'or triangles')
# Handling of linewidths, shading, edgecolors and antialiased as
# in Axes.pcolor
linewidths = (0.25,)
if 'linewidth' in kwargs:
kwargs['linewidths'] = kwargs.pop('linewidth')
kwargs.setdefault('linewidths', linewidths)
edgecolors = 'none'
if 'edgecolor' in kwargs:
kwargs['edgecolors'] = kwargs.pop('edgecolor')
ec = kwargs.setdefault('edgecolors', edgecolors)
if 'antialiased' in kwargs:
kwargs['antialiaseds'] = kwargs.pop('antialiased')
if 'antialiaseds' not in kwargs and ec.lower() == "none":
kwargs['antialiaseds'] = False
if shading == 'gouraud':
if facecolors is not None:
raise ValueError('Gouraud shading does not support the use '
'of facecolors kwarg')
if len(C) != len(tri.x):
raise ValueError('For gouraud shading, the length of color '
'values array must be the same as the '
'number of triangulation points')
collection = TriMesh(tri, **kwargs)
else:
# Vertices of triangles.
maskedTris = tri.get_masked_triangles()
verts = np.concatenate((tri.x[maskedTris][..., np.newaxis],
tri.y[maskedTris][..., np.newaxis]), axis=2)
# Color values.
if facecolors is None:
# One color per triangle, the mean of the 3 vertex color values.
C = C[maskedTris].mean(axis=1)
elif tri.mask is not None:
# Remove color values of masked triangles.
C = C.compress(1-tri.mask)
collection = PolyCollection(verts, **kwargs)
collection.set_alpha(alpha)
collection.set_array(C)
if norm is not None:
if not isinstance(norm, Normalize):
msg = "'norm' must be an instance of 'Normalize'"
raise ValueError(msg)
collection.set_cmap(cmap)
collection.set_norm(norm)
if vmin is not None or vmax is not None:
collection.set_clim(vmin, vmax)
else:
collection.autoscale_None()
ax.grid(False)
minx = tri.x.min()
maxx = tri.x.max()
miny = tri.y.min()
maxy = tri.y.max()
corners = (minx, miny), (maxx, maxy)
ax.update_datalim(corners)
ax.autoscale_view()
ax.add_collection(collection)
return collection
def tripcolor(ax,
*args,
alpha=1.0,
norm=None,
cmap=None,
vmin=None,
vmax=None,
shading='flat',
facecolors=None,
**kwargs):
"""
Create a pseudocolor plot of an unstructured triangular grid.
The triangulation can be specified in one of two ways; either::
tripcolor(triangulation, ...)
where triangulation is a `.Triangulation` object, or
::
tripcolor(x, y, ...)
tripcolor(x, y, triangles, ...)
tripcolor(x, y, triangles=triangles, ...)
tripcolor(x, y, mask=mask, ...)
tripcolor(x, y, triangles, mask=mask, ...)
in which case a Triangulation object will be created. See `.Triangulation`
for a explanation of these possibilities.
The next argument must be *C*, the array of color values, either
one per point in the triangulation if color values are defined at
points, or one per triangle in the triangulation if color values
are defined at triangles. If there are the same number of points
and triangles in the triangulation it is assumed that color
values are defined at points; to force the use of color values at
triangles use the kwarg ``facecolors=C`` instead of just ``C``.
*shading* may be 'flat' (the default) or 'gouraud'. If *shading*
is 'flat' and C values are defined at points, the color values
used for each triangle are from the mean C of the triangle's
three points. If *shading* is 'gouraud' then color values must be
defined at points.
The remaining kwargs are the same as for `~.Axes.pcolor`.
"""
_api.check_in_list(['flat', 'gouraud'], shading=shading)
tri, args, kwargs = Triangulation.get_from_args_and_kwargs(*args, **kwargs)
# C is the colors array defined at either points or faces (i.e. triangles).
# If facecolors is None, C are defined at points.
# If facecolors is not None, C are defined at faces.
if facecolors is not None:
C = facecolors
else:
C = np.asarray(args[0])
# If there are a different number of points and triangles in the
# triangulation, can omit facecolors kwarg as it is obvious from
# length of C whether it refers to points or faces.
# Do not do this for gouraud shading.
if (facecolors is None and len(C) == len(tri.triangles)
and len(C) != len(tri.x) and shading != 'gouraud'):
facecolors = C
# Check length of C is OK.
if ((facecolors is None and len(C) != len(tri.x))
or (facecolors is not None and len(C) != len(tri.triangles))):
raise ValueError('Length of color values array must be the same '
'as either the number of triangulation points '
'or triangles')
# Handling of linewidths, shading, edgecolors and antialiased as
# in Axes.pcolor
linewidths = (0.25, )
if 'linewidth' in kwargs:
kwargs['linewidths'] = kwargs.pop('linewidth')
kwargs.setdefault('linewidths', linewidths)
edgecolors = 'none'
if 'edgecolor' in kwargs:
kwargs['edgecolors'] = kwargs.pop('edgecolor')
ec = kwargs.setdefault('edgecolors', edgecolors)
if 'antialiased' in kwargs:
kwargs['antialiaseds'] = kwargs.pop('antialiased')
if 'antialiaseds' not in kwargs and ec.lower() == "none":
kwargs['antialiaseds'] = False
if shading == 'gouraud':
if facecolors is not None:
raise ValueError('Gouraud shading does not support the use '
'of facecolors kwarg')
if len(C) != len(tri.x):
raise ValueError('For gouraud shading, the length of color '
'values array must be the same as the '
'number of triangulation points')
collection = TriMesh(tri, **kwargs)
else:
# Vertices of triangles.
maskedTris = tri.get_masked_triangles()
verts = np.stack((tri.x[maskedTris], tri.y[maskedTris]), axis=-1)
# Color values.
if facecolors is None:
# One color per triangle, the mean of the 3 vertex color values.
C = C[maskedTris].mean(axis=1)
elif tri.mask is not None:
# Remove color values of masked triangles.
C = C[~tri.mask]
collection = PolyCollection(verts, **kwargs)
collection.set_alpha(alpha)
collection.set_array(C)
_api.check_isinstance((Normalize, None), norm=norm)
collection.set_cmap(cmap)
collection.set_norm(norm)
collection._scale_norm(norm, vmin, vmax)
ax.grid(False)
minx = tri.x.min()
maxx = tri.x.max()
miny = tri.y.min()
maxy = tri.y.max()
corners = (minx, miny), (maxx, maxy)
ax.update_datalim(corners)
ax.autoscale_view()
ax.add_collection(collection)
return collection
def tripcolor(ax,
*args,
alpha=1.0,
norm=None,
cmap=None,
vmin=None,
vmax=None,
shading='flat',
facecolors=None,
**kwargs):
"""
Create a pseudocolor plot of an unstructured triangular grid.
Call signatures::
tripcolor(triangulation, C, *, ...)
tripcolor(x, y, C, *, [triangles=triangles], [mask=mask], ...)
The triangular grid can be specified either by passing a `.Triangulation`
object as the first parameter, or by passing the points *x*, *y* and
optionally the *triangles* and a *mask*. See `.Triangulation` for an
explanation of these parameters.
If neither of *triangulation* or *triangles* are given, the triangulation
is calculated on the fly. In this case, it does not make sense to provide
colors at the triangle faces via *C* or *facecolors* because there are
multiple possible triangulations for a group of points and you don't know
which triangles will be constructed.
Parameters
----------
triangulation : `.Triangulation`
An already created triangular grid.
x, y, triangles, mask
Parameters defining the triangular grid. See `.Triangulation`.
This is mutually exclusive with specifying *triangulation*.
C : array-like
The color values, either for the points or for the triangles. Which one
is automatically inferred from the length of *C*, i.e. does it match
the number of points or the number of triangles. If there are the same
number of points and triangles in the triangulation it is assumed that
color values are defined at points; to force the use of color values at
triangles use the keyword argument ``facecolors=C`` instead of just
``C``.
This parameter is position-only.
facecolors : array-like, optional
Can be used alternatively to *C* to specify colors at the triangle
faces. This parameter takes precedence over *C*.
shading : {'flat', 'gouraud'}, default: 'flat'
If 'flat' and the color values *C* are defined at points, the color
values used for each triangle are from the mean C of the triangle's
three points. If *shading* is 'gouraud' then color values must be
defined at points.
other_parameters
All other parameters are the same as for `~.Axes.pcolor`.
Notes
-----
It is possible to pass the triangles positionally, i.e.
``tripcolor(x, y, triangles, C, ...)``. However, this is discouraged.
For more clarity, pass *triangles* via keyword argument.
"""
_api.check_in_list(['flat', 'gouraud'], shading=shading)
tri, args, kwargs = Triangulation.get_from_args_and_kwargs(*args, **kwargs)
# Parse the color to be in one of (the other variable will be None):
# - facecolors: if specified at the triangle faces
# - point_colors: if specified at the points
if facecolors is not None:
if args:
_api.warn_external(
"Positional parameter C has no effect when the keyword "
"facecolors is given")
point_colors = None
if len(facecolors) != len(tri.triangles):
raise ValueError("The length of facecolors must match the number "
"of triangles")
else:
# Color from positional parameter C
if not args:
raise ValueError(
"Missing color parameter. Please pass C positionally or "
"facecolors via keyword")
elif len(args) > 1:
_api.warn_external(
"Additional positional parameters {args[1:]!r} are ignored")
C = np.asarray(args[0])
if len(C) == len(tri.x):
# having this before the len(tri.triangles) comparison gives
# precedence to nodes if there are as many nodes as triangles
point_colors = C
facecolors = None
elif len(C) == len(tri.triangles):
point_colors = None
facecolors = C
else:
raise ValueError('The length of C must match either the number '
'of points or the number of triangles')
# Handling of linewidths, shading, edgecolors and antialiased as
# in Axes.pcolor
linewidths = (0.25, )
if 'linewidth' in kwargs:
kwargs['linewidths'] = kwargs.pop('linewidth')
kwargs.setdefault('linewidths', linewidths)
edgecolors = 'none'
if 'edgecolor' in kwargs:
kwargs['edgecolors'] = kwargs.pop('edgecolor')
ec = kwargs.setdefault('edgecolors', edgecolors)
if 'antialiased' in kwargs:
kwargs['antialiaseds'] = kwargs.pop('antialiased')
if 'antialiaseds' not in kwargs and ec.lower() == "none":
kwargs['antialiaseds'] = False
_api.check_isinstance((Normalize, None), norm=norm)
if shading == 'gouraud':
if facecolors is not None:
raise ValueError(
"shading='gouraud' can only be used when the colors "
"are specified at the points, not at the faces.")
collection = TriMesh(tri,
alpha=alpha,
array=point_colors,
cmap=cmap,
norm=norm,
**kwargs)
else:
# Vertices of triangles.
maskedTris = tri.get_masked_triangles()
verts = np.stack((tri.x[maskedTris], tri.y[maskedTris]), axis=-1)
# Color values.
if facecolors is None:
# One color per triangle, the mean of the 3 vertex color values.
colors = point_colors[maskedTris].mean(axis=1)
elif tri.mask is not None:
# Remove color values of masked triangles.
colors = facecolors[~tri.mask]
else:
colors = facecolors
collection = PolyCollection(verts,
alpha=alpha,
array=colors,
cmap=cmap,
norm=norm,
**kwargs)
collection._scale_norm(norm, vmin, vmax)
ax.grid(False)
minx = tri.x.min()
maxx = tri.x.max()
miny = tri.y.min()
maxy = tri.y.max()
corners = (minx, miny), (maxx, maxy)
ax.update_datalim(corners)
ax.autoscale_view()
ax.add_collection(collection)
return collection
def tripcolor(ax, *args, **kwargs):
"""
Create a pseudocolor plot of an unstructured triangular grid to
the :class:`~matplotlib.axes.Axes`.
The triangulation can be specified in one of two ways; either::
tripcolor(triangulation, ...)
where triangulation is a :class:`~matplotlib.tri.Triangulation`
object, or
::
tripcolor(x, y, ...)
tripcolor(x, y, triangles, ...)
tripcolor(x, y, triangles=triangles, ...)
tripcolor(x, y, mask=mask, ...)
tripcolor(x, y, triangles, mask=mask, ...)
in which case a Triangulation object will be created. See
:class:`~matplotlib.tri.Triangulation` for a explanation of these
possibilities.
The next argument must be *C*, the array of color values, one per
point in the triangulation.
*shading* may be 'flat', 'faceted' or 'gouraud'. If *shading* is
'flat' or 'faceted', the colors used for each triangle are from
the mean C of the triangle's three points.
The remaining kwargs are the same as for
:meth:`~matplotlib.axes.Axes.pcolor`.
**Example:**
.. plot:: mpl_examples/pylab_examples/tripcolor_demo.py
"""
if not ax._hold: ax.cla()
alpha = kwargs.pop('alpha', 1.0)
norm = kwargs.pop('norm', None)
cmap = kwargs.pop('cmap', None)
vmin = kwargs.pop('vmin', None)
vmax = kwargs.pop('vmax', None)
shading = kwargs.pop('shading', 'flat')
tri, args, kwargs = Triangulation.get_from_args_and_kwargs(*args, **kwargs)
x = tri.x
y = tri.y
triangles = tri.get_masked_triangles()
C = np.asarray(args[0])
if C.shape != x.shape:
raise ValueError('C array must have same length as triangulation x and'
' y arrays')
if shading == 'gouraud':
collection = TriMesh(tri, **kwargs)
else:
if shading == 'faceted':
edgecolors = (0, 0, 0, 1),
linewidths = (0.25, )
else:
edgecolors = 'face'
linewidths = (1.0, )
kwargs.setdefault('edgecolors', edgecolors)
kwargs.setdefault('antialiaseds', (0, ))
kwargs.setdefault('linewidths', linewidths)
# Vertices of triangles.
verts = np.concatenate(
(x[triangles][..., np.newaxis], y[triangles][..., np.newaxis]),
axis=2)
# Color values, one per triangle, mean of the 3 vertex color values.
C = C[triangles].mean(axis=1)
collection = PolyCollection(verts, **kwargs)
collection.set_alpha(alpha)
collection.set_array(C)
if norm is not None: assert (isinstance(norm, Normalize))
collection.set_cmap(cmap)
collection.set_norm(norm)
if vmin is not None or vmax is not None:
collection.set_clim(vmin, vmax)
else:
collection.autoscale_None()
ax.grid(False)
minx = tri.x.min()
maxx = tri.x.max()
miny = tri.y.min()
maxy = tri.y.max()
corners = (minx, miny), (maxx, maxy)
ax.update_datalim(corners)
ax.autoscale_view()
ax.add_collection(collection)
return collection
collection.set_array(mag)
collection.norm.vmin=0
collection.norm.vmax=0.5
# <codecell>
fig = plt.figure(figsize=(12,12))
ax=fig.add_subplot(111)
m.drawmapboundary(fill_color='0.3')
#m.drawcoastlines()
#m.fillcontinents()
# add the speed as colored triangles
ax.add_collection(collection) # add polygons to axes on basemap instance
# add the vectors
Q = m.quiver(xc,yc,u,v,scale=30)
# add a key for the vectors
qk = plt.quiverkey(Q,0.1,0.1,0.20,'0.2 m/s',labelpos='W')
plt.title('FVCOM Surface Current speed at %s UTC' % timestamp)
# <codecell>
# try using the TriMesh collection: can't figure this out
collection2 = TriMesh(tri)
fig = plt.figure(figsize=(12,12))
ax = fig.add_subplot(111)
ax.add_collection(collection2)
# <codecell>