def _process(self, element, key=None):
try:
from matplotlib.contour import QuadContourSet
from matplotlib.axes import Axes
from matplotlib.figure import Figure
except ImportError:
raise ImportError("contours operation requires matplotlib.")
extent = element.range(0) + element.range(1)[::-1]
if type(element) is Raster:
data = [np.flipud(element.data)]
elif isinstance(element, Image):
data = [np.flipud(element.dimension_values(2, flat=False))]
elif isinstance(element, QuadMesh):
data = (element.dimension_values(0, False),
element.dimension_values(1, False), element.data[2])
if isinstance(self.p.levels, int):
levels = self.p.levels + 2 if self.p.filled else self.p.levels + 3
zmin, zmax = element.range(2)
levels = np.linspace(zmin, zmax, levels)
else:
levels = self.p.levels
xdim, ydim = element.dimensions('key', label=True)
fig = Figure()
ax = Axes(fig, [0, 0, 1, 1])
contour_set = QuadContourSet(ax,
*data,
filled=self.p.filled,
extent=extent,
levels=levels)
if self.p.filled:
contour_type = Polygons
else:
contour_type = Contours
vdims = element.vdims[:1]
paths = []
empty = np.full((1, 2), np.NaN)
for level, cset in zip(contour_set.get_array(),
contour_set.collections):
subpaths = []
for path in cset.get_paths():
if path.codes is None:
subpaths.append(path.vertices)
else:
subpaths += np.split(path.vertices,
np.where(path.codes == 1)[0][1:])
subpath = np.concatenate(
[p for sp in subpaths for p in (sp, empty)][:-1])
paths.append({(xdim, ydim): subpath, element.vdims[0].name: level})
contours = contour_type(paths,
label=element.label,
kdims=element.kdims,
vdims=vdims)
if self.p.overlaid:
contours = element * contours
return contours
def _process(self, element, key=None):
try:
from matplotlib.contour import QuadContourSet
from matplotlib.axes import Axes
from matplotlib.figure import Figure
from matplotlib.dates import num2date, date2num
except ImportError:
raise ImportError("contours operation requires matplotlib.")
extent = element.range(0) + element.range(1)[::-1]
xs = element.dimension_values(0, True, flat=False)
ys = element.dimension_values(1, True, flat=False)
zs = element.dimension_values(2, flat=False)
# Ensure that coordinate arrays specify bin centers
if xs.shape[0] != zs.shape[0]:
xs = xs[:-1] + np.diff(xs, axis=0)/2.
if xs.shape[1] != zs.shape[1]:
xs = xs[:, :-1] + (np.diff(xs, axis=1)/2.)
if ys.shape[0] != zs.shape[0]:
ys = ys[:-1] + np.diff(ys, axis=0)/2.
if ys.shape[1] != zs.shape[1]:
ys = ys[:, :-1] + (np.diff(ys, axis=1)/2.)
data = (xs, ys, zs)
# if any data is a datetime, transform to matplotlib's numerical format
data_is_datetime = tuple(isdatetime(arr) for k, arr in enumerate(data))
if any(data_is_datetime):
data = tuple(
date2num(d) if is_datetime else d
for d, is_datetime in zip(data, data_is_datetime)
)
xdim, ydim = element.dimensions('key', label=True)
if self.p.filled:
contour_type = Polygons
else:
contour_type = Contours
vdims = element.vdims[:1]
kwargs = {}
levels = self.p.levels
zmin, zmax = element.range(2)
if isinstance(self.p.levels, int):
if zmin == zmax:
contours = contour_type([], [xdim, ydim], vdims)
return (element * contours) if self.p.overlaid else contours
data += (levels,)
else:
kwargs = {'levels': levels}
fig = Figure()
ax = Axes(fig, [0, 0, 1, 1])
contour_set = QuadContourSet(ax, *data, filled=self.p.filled,
extent=extent, **kwargs)
levels = np.array(contour_set.get_array())
crange = levels.min(), levels.max()
if self.p.filled:
levels = levels[:-1] + np.diff(levels)/2.
vdims = [vdims[0].clone(range=crange)]
paths = []
empty = np.array([[np.nan, np.nan]])
for level, cset in zip(levels, contour_set.collections):
exteriors = []
interiors = []
for geom in cset.get_paths():
interior = []
polys = geom.to_polygons(closed_only=False)
for ncp, cp in enumerate(polys):
if any(data_is_datetime[0:2]):
# transform x/y coordinates back to datetimes
xs, ys = np.split(cp, 2, axis=1)
if data_is_datetime[0]:
xs = np.array(num2date(xs))
if data_is_datetime[1]:
ys = np.array(num2date(ys))
cp = np.concatenate((xs, ys), axis=1)
if ncp == 0:
exteriors.append(cp)
exteriors.append(empty)
else:
interior.append(cp)
if len(polys):
interiors.append(interior)
if not exteriors:
continue
geom = {
element.vdims[0].name:
num2date(level) if data_is_datetime[2] else level,
(xdim, ydim): np.concatenate(exteriors[:-1])
}
if self.p.filled and interiors:
geom['holes'] = interiors
paths.append(geom)
contours = contour_type(paths, label=element.label, kdims=element.kdims, vdims=vdims)
if self.p.overlaid:
contours = element * contours
return contours
def _process(self, element, key=None):
try:
from matplotlib.contour import QuadContourSet
from matplotlib.axes import Axes
from matplotlib.figure import Figure
except ImportError:
raise ImportError("contours operation requires matplotlib.")
extent = element.range(0) + element.range(1)[::-1]
xs = element.dimension_values(0, True, flat=False)
ys = element.dimension_values(1, True, flat=False)
zs = element.dimension_values(2, flat=False)
# Ensure that coordinate arrays specify bin centers
if xs.shape[0] != zs.shape[0]:
xs = xs[:-1] + np.diff(xs, axis=0)/2.
if xs.shape[1] != zs.shape[1]:
xs = xs[:, :-1] + (np.diff(xs, axis=1)/2.)
if ys.shape[0] != zs.shape[0]:
ys = ys[:-1] + np.diff(ys, axis=0)/2.
if ys.shape[1] != zs.shape[1]:
ys = ys[:, :-1] + (np.diff(ys, axis=1)/2.)
data = (xs, ys, zs)
xdim, ydim = element.dimensions('key', label=True)
if self.p.filled:
contour_type = Polygons
else:
contour_type = Contours
vdims = element.vdims[:1]
kwargs = {}
levels = self.p.levels
zmin, zmax = element.range(2)
if isinstance(self.p.levels, int):
if zmin == zmax:
contours = contour_type([], [xdim, ydim], vdims)
return (element * contours) if self.p.overlaid else contours
data += (levels,)
else:
kwargs = {'levels': levels}
fig = Figure()
ax = Axes(fig, [0, 0, 1, 1])
contour_set = QuadContourSet(ax, *data, filled=self.p.filled,
extent=extent, **kwargs)
levels = np.array(contour_set.get_array())
crange = levels.min(), levels.max()
if self.p.filled:
levels = levels[:-1] + np.diff(levels)/2.
vdims = [vdims[0].clone(range=crange)]
paths = []
empty = np.array([[np.nan, np.nan]])
for level, cset in zip(levels, contour_set.collections):
exteriors = []
interiors = []
for geom in cset.get_paths():
interior = []
polys = geom.to_polygons(closed_only=False)
for ncp, cp in enumerate(polys):
if ncp == 0:
exteriors.append(cp)
exteriors.append(empty)
else:
interior.append(cp)
if len(polys):
interiors.append(interior)
if not exteriors:
continue
geom = {element.vdims[0].name: level, (xdim, ydim): np.concatenate(exteriors[:-1])}
if self.p.filled and interiors:
geom['holes'] = interiors
paths.append(geom)
contours = contour_type(paths, label=element.label, kdims=element.kdims, vdims=vdims)
if self.p.overlaid:
contours = element * contours
return contours