Source code for ipyvolume.examples

"""Some examples for quick testing/demonstrations.

All function accept `show` and `draw` arguments

  * If `draw` is `True` it will return the widgets (Scatter, Volume, Mesh)
  * If `draw` is `False`, it will return the data
  * if `show` is `False`, `ipv.show()` will not be called.
"""

import warnings
import numpy as np
from numpy import cos, sin, pi

try:
    import scipy.ndimage
    import scipy.special
except:
    pass  # it's ok, it's not crucial
# __all__ = ["example_ylm"]


[docs]def xyz(shape=128, limits=[-3, 3], spherical=False, sparse=True, centers=False): dim = 3 try: shape[0] except: shape = [shape] * dim try: limits[0][0] # pylint: disable=unsubscriptable-object except: limits = [limits] * dim if centers: v = [ slice(vmin + (vmax - vmin) / float(N) / 2, vmax - (vmax - vmin) / float(N) / 4, (vmax - vmin) / float(N)) for (vmin, vmax), N in zip(limits, shape) ] else: v = [ slice(vmin, vmax + (vmax - vmin) / float(N) / 2, (vmax - vmin) / float(N - 1)) for (vmin, vmax), N in zip(limits, shape) ] if sparse: x, y, z = np.ogrid.__getitem__(v) else: x, y, z = np.mgrid.__getitem__(v) if spherical: r = np.linalg.norm([x, y, z]) theta = np.arctan2(y, x) phi = np.arccos(z / r) return x, y, z, r, theta, phi else: return x, y, z
[docs]def example_ylm(m=0, n=2, shape=128, limits=[-4, 4], draw=True, show=True, **kwargs): """Show a spherical harmonic.""" import ipyvolume.pylab as p3 __, __, __, r, theta, phi = xyz(shape=shape, limits=limits, spherical=True) radial = np.exp(-(r - 2) ** 2) data = np.abs(scipy.special.sph_harm(m, n, theta, phi) ** 2) * radial # pylint: disable=no-member if draw: vol = p3.volshow(data=data, **kwargs) if show: p3.show() return vol else: return data
# return ipyvolume.volshow(data=data.T, **kwargs)
[docs]def ball(rmax=3, rmin=0, shape=128, limits=[-4, 4], draw=True, show=True, **kwargs): """Show a ball.""" import ipyvolume.pylab as p3 __, __, __, r, _theta, _phi = xyz(shape=shape, limits=limits, spherical=True) data = r * 0 data[(r < rmax) & (r >= rmin)] = 0.5 if "data_min" not in kwargs: kwargs["data_min"] = 0 if "data_max" not in kwargs: kwargs["data_max"] = 1 data = data.T if draw: vol = p3.volshow(data=data, **kwargs) if show: p3.show() return vol else: return data
# http://graphics.stanford.edu/data/voldata/
[docs]def klein_bottle( draw=True, show=True, figure8=False, endpoint=True, uv=True, wireframe=False, texture=None, both=False, interval=1000, ): """Show one or two Klein bottles.""" import ipyvolume.pylab as p3 # http://paulbourke.net/geometry/klein/ u = np.linspace(0, 2 * pi, num=40, endpoint=endpoint) v = np.linspace(0, 2 * pi, num=40, endpoint=endpoint) u, v = np.meshgrid(u, v) if both: x1, y1, z1, _u1, _v1 = klein_bottle(endpoint=endpoint, draw=False, show=False) x2, y2, z2, _u2, _v2 = klein_bottle(endpoint=endpoint, draw=False, show=False, figure8=True) x = [x1, x2] y = [y1, y2] z = [z1, z2] else: if figure8: # u -= np.pi # v -= np.pi a = 2 s = 5 x = s * (a + cos(u / 2) * sin(v) - sin(u / 2) * sin(2 * v) / 2) * cos(u) y = s * (a + cos(u / 2) * sin(v) - sin(u / 2) * sin(2 * v) / 2) * sin(u) z = s * (sin(u / 2) * sin(v) + cos(u / 2) * sin(2 * v) / 2) else: r = 4 * (1 - cos(u) / 2) x = 6 * cos(u) * (1 + sin(u)) + r * cos(u) * cos(v) * (u < pi) + r * cos(v + pi) * (u >= pi) y = 16 * sin(u) + r * sin(u) * cos(v) * (u < pi) z = r * sin(v) if draw: if texture: uv = True if uv: mesh = p3.plot_mesh( x, y, z, wrapx=not endpoint, wrapy=not endpoint, u=u / (2 * np.pi), v=v / (2 * np.pi), wireframe=wireframe, texture=texture, ) else: mesh = p3.plot_mesh(x, y, z, wrapx=not endpoint, wrapy=not endpoint, wireframe=wireframe, texture=texture) if show: if both: p3.animation_control(mesh, interval=interval) p3.squarelim() p3.show() return mesh else: return x, y, z, u, v
[docs]def brain( draw=True, show=True, fiducial=True, flat=True, inflated=True, subject='S1', interval=1000, uv=True, color=None ): """Show a human brain model. Requirement: $ pip install https://github.com/gallantlab/pycortex """ import ipyvolume as ipv try: import cortex except: warnings.warn("it seems pycortex is not installed, which is needed for this example") raise xlist, ylist, zlist = [], [], [] polys_list = [] def add(pts, polys): xlist.append(pts[:, 0]) ylist.append(pts[:, 1]) zlist.append(pts[:, 2]) polys_list.append(polys) def n(x): return (x - x.min()) / x.ptp() if fiducial or color is True: pts, polys = cortex.db.get_surf('S1', 'fiducial', merge=True) x, y, z = pts.T r = n(x) g = n(y) b = n(z) if color is True: color = np.array([r, g, b]).T.copy() else: color = None if fiducial: add(pts, polys) else: if color is False: color = None if inflated: add(*cortex.db.get_surf('S1', 'inflated', merge=True, nudge=True)) u = v = None if flat or uv: pts, polys = cortex.db.get_surf('S1', 'flat', merge=True, nudge=True) x, y, z = pts.T u = n(x) v = n(y) if flat: add(pts, polys) polys_list.sort(key=lambda x: len(x)) polys = polys_list[0] if draw: if color is None: mesh = ipv.plot_trisurf(xlist, ylist, zlist, polys, u=u, v=v) else: mesh = ipv.plot_trisurf(xlist, ylist, zlist, polys, color=color, u=u, v=v) if show: if len(x) > 1: ipv.animation_control(mesh, interval=interval) ipv.squarelim() ipv.show() return mesh else: return xlist, ylist, zlist, polys
[docs]def gaussian(N=1000, draw=True, show=True, seed=42, color=None, marker='sphere'): """Show N random gaussian distributed points using a scatter plot.""" import ipyvolume as ipv rng = np.random.RandomState(seed) # pylint: disable=no-member x, y, z = rng.normal(size=(3, N)) if draw: if color: mesh = ipv.scatter(x, y, z, marker=marker, color=color) else: mesh = ipv.scatter(x, y, z, marker=marker) if show: # ipv.squarelim() ipv.show() return mesh else: return x, y, z