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svg display for numpy geometries
# -*- coding: utf-8 -*-
r"""
-----------
svg_npGeom.py
-----------
Author :
Dan_Patterson@carleton.ca
`<https://github.com/Dan-Patterson>`_.
Modified :
2020-01-21
"""
import sys
import numpy as np
script = sys.argv[0] # print this should you need to locate the script
__all__ = [_svg]
# ----------------------------------------------------------------------------
# ---- (1) ...
#
# ---- displaying Geo and ndarrays
#
def _svg(g, as_polygon=True):
"""Format and show a Geo array, np.ndarray or list structure in SVG format.
Notes
-----
Geometry must be expected to form polylines or polygons.
IPython required.
>>> from IPython.display import SVG
alternate colors:
white, silver, gray black, red, maroon, purple, blue, navy, aqua,
green, teal, lime, yellow, magenta, cyan
"""
def svg_path(g_bits, scale_by, o_f_s):
"""Make the svg from a list of 2d arrays"""
opacity, fill_color, stroke = o_f_s
pth = [" M {},{} " + "L {},{} "*(len(b) - 1) for b in g_bits]
ln = [pth[i].format(*b.ravel()) for i, b in enumerate(g_bits)]
pth = "".join(ln) + "z"
s = ('<path fill-rule="evenodd" fill="{0}" stroke="{1}" '
'stroke-width="{2}" opacity="{3}" d="{4}"/>'
).format(fill_color, stroke, 1.5 * scale_by, opacity, pth)
return s
# ----
msg0 = "\nImport error..\n>>> from IPython.display import SVG\nfailed."
msg1 = "A Geo array or ndarray (with ndim >=2) is required."
# ----
# Geo array, np.ndarray check
try:
from IPython.display import SVG
except ImportError:
print(dedent(msg0))
return None
# ---- checks for Geo or ndarray. Convert lists, tuples to np.ndarray
if isinstance(g, (list, tuple)):
g = np.asarray(g)
if ('Geo' in str(type(g))) & (issubclass(g.__class__, np.ndarray)):
GA = True
g_bits = g.bits
elif isinstance(g, np.ndarray):
GA = False
if g.ndim == 2:
g_bits = [g]
L, B = g.min(axis=0)
R, T = g.max(axis=0)
elif g.ndim == 3:
g_bits = [g[i] for i in range(g.shape[0])]
L, B = g.min(axis=(0, 1))
R, T = g.max(axis=(0, 1))
elif g.dtype.kind == 'O':
g_bits = []
for i, b in enumerate(g):
b = np.array(b)
if b.ndim == 2:
g_bits.append(b)
elif b.ndim == 3:
g_bits.extend([b[i] for i in range(b.shape[0])])
L, B = np.min(np.vstack([np.min(i, axis=0) for i in g_bits]),
axis=0)
R, T = np.max(np.vstack([np.max(i, axis=0) for i in g_bits]),
axis=0)
else:
print(msg1)
return None
else:
print(msg1)
return None
# ----
# derive parameters
if as_polygon:
o_f_s = ["0.75", "red", "black"] # opacity, fill_color, stroke color
else:
o_f_s = ["1.0", "none", "red"]
# ----
d_x, d_y = (R - L, T - B)
hght = min([max([100., d_y]), 200])
width = int(d_x/d_y * hght)
scale_by = max([d_x, d_y]) / max([width, hght])
# ----
# derive the geometry path
pth_geom = svg_path(g_bits, scale_by, o_f_s) # ---- svg path string
# construct the final output
view_box = "{} {} {} {}".format(L, B, d_x, d_y)
transform = "matrix(1,0,0,-1,0,{0})".format(T + B)
hdr = '<svg xmlns="http://www.w3.org/2000/svg" ' \
'xmlns:xlink="http://www.w3.org/1999/xlink" '
f0 = 'width="{}" height="{}" viewBox="{}" '.format(width, hght, view_box)
f1 = 'preserveAspectRatio="xMinYMin meet">'
f2 = '<g transform="{}">{}</g></svg>'.format(transform, pth_geom)
s = hdr + f0 + f1 + f2
if GA: # Geo array display
g.SVG = s
return SVG(g.SVG) # plot the representation
else: # np.ndarray display
return SVG(s)
# ---- Final main section ----------------------------------------------------
if __name__ == "__main__":
"""optional location for parameters"""
print("\nRunning... {}\n".format(script))
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