def chunk_limit_setup():
N = 100_000
dpi = 500
w = 5 * dpi
h = 6 * dpi
# just fit in the width
x = np.linspace(0, w, N)
# and go top-to-bottom
y = np.ones(N) * h
y[::2] = 0
idt = IdentityTransform()
# make a renderer
ra = RendererAgg(w, h, dpi)
# setup the minimal gc to draw a line
gc = ra.new_gc()
gc.set_linewidth(1)
gc.set_foreground('r')
# make a Path
p = Path(np.vstack((x, y)).T)
# effectively disable path simplification (but leaving it "on")
p.simplify_threshold = 0
return ra, gc, p, idt
def onselect(vertices):
path = Path( vertices, closed = True)
# fraction of a pixel difference below which vertices will be simplified out
path.simplify_threshold = 1.0
path.should_simplify = True
# path.contains_points(points = )
vertfilename = "maskselection.npz"
savez_dict = dict(vertices = vertices)
np.savez_compressed(vertfilename, **savez_dict)
def draw_path(self, gc, path, transform, rgbFace=None):
# docstring inherited
nmax = mpl.rcParams['agg.path.chunksize'] # here at least for testing
npts = path.vertices.shape[0]
if (npts > nmax > 100 and path.should_simplify and rgbFace is None
and gc.get_hatch() is None):
nch = np.ceil(npts / nmax)
chsize = int(np.ceil(npts / nch))
i0 = np.arange(0, npts, chsize)
i1 = np.zeros_like(i0)
i1[:-1] = i0[1:] - 1
i1[-1] = npts
for ii0, ii1 in zip(i0, i1):
v = path.vertices[ii0:ii1, :]
c = path.codes
if c is not None:
c = c[ii0:ii1]
c[0] = Path.MOVETO # move to end of last chunk
p = Path(v, c)
p.simplify_threshold = path.simplify_threshold
try:
self._renderer.draw_path(gc, p, transform, rgbFace)
except OverflowError:
msg = (
"Exceeded cell block limit in Agg.\n\n"
"Please reduce the value of "
f"rcParams['agg.path.chunksize'] (currently {nmax}) "
"or increase the path simplification threshold"
"(rcParams['path.simplify_threshold'] = "
f"{mpl.rcParams['path.simplify_threshold']:.2f} by "
"default and path.simplify_threshold = "
f"{path.simplify_threshold:.2f} on the input).")
raise OverflowError(msg) from None
else:
try:
self._renderer.draw_path(gc, path, transform, rgbFace)
except OverflowError:
cant_chunk = ''
if rgbFace is not None:
cant_chunk += "- can not split filled path\n"
if gc.get_hatch() is not None:
cant_chunk += "- can not split hatched path\n"
if not path.should_simplify:
cant_chunk += "- path.should_simplify is False\n"
if len(cant_chunk):
msg = (
"Exceeded cell block limit in Agg, however for the "
"following reasons:\n\n"
f"{cant_chunk}\n"
"we can not automatically split up this path to draw."
"\n\nPlease manually simplify your path.")
else:
inc_threshold = (
"or increase the path simplification threshold"
"(rcParams['path.simplify_threshold'] = "
f"{mpl.rcParams['path.simplify_threshold']} "
"by default and path.simplify_threshold "
f"= {path.simplify_threshold} "
"on the input).")
if nmax > 100:
msg = (
"Exceeded cell block limit in Agg. Please reduce "
"the value of rcParams['agg.path.chunksize'] "
f"(currently {nmax}) {inc_threshold}")
else:
msg = ("Exceeded cell block limit in Agg. Please set "
"the value of rcParams['agg.path.chunksize'], "
f"(currently {nmax}) to be greater than 100 " +
inc_threshold)
raise OverflowError(msg) from None
# <codecell>
import matplotlib.path as mpath
from matplotlib.path import Path
vertfilename = "maskselection.npz"
data = np.load(vertfilename)
verts = data['vertices']
path = Path(verts, closed = True)
print len(path)
path.should_simplify = True
path.simplify_threshold = 10.0
# <codecell>
vertices = []
codes = []
for (vertex, code) in path.iter_segments(simplify = True):
vertices.append(vertex.tolist())
codes.append(code)
# <codecell>
cleanpath = Path(vertices, codes)
len(cleanpath)
# <codecell>
