slice3d.py

#!/usr/bin/env python
"""
slice plot
https://nbviewer.jupyter.org/github/empet/Plotly-plots/blob/master/Plotly-Slice-in-volumetric-data.ipynb
"""
import plotly
import plotly.graph_objs as pgo
import numpy as np

pl_BrBG = [
    [0.0, "rgb(84, 48, 5)"],
    [0.1, "rgb(138, 80, 9)"],
    [0.2, "rgb(191, 129, 45)"],
    [0.3, "rgb(222, 192, 123)"],
    [0.4, "rgb(246, 232, 195)"],
    [0.5, "rgb(244, 244, 244)"],
    [0.6, "rgb(199, 234, 229)"],
    [0.7, "rgb(126, 203, 192)"],
    [0.8, "rgb(53, 151, 143)"],
    [0.9, "rgb(0, 101, 93)"],
    [1.0, "rgb(0, 60, 48)"],
]


def get_the_slice(x, y, z, surfacecolor, colorscale=pl_BrBG, showscale=False):
    """https://plot.ly/python/reference/#surface"""

    return pgo.Surface(
        x=x, y=y, z=z, surfacecolor=surfacecolor, colorscale=colorscale, showscale=showscale
    )


def get_lims_colors(surfacecolor):  # color limits for a slice
    return np.min(surfacecolor), np.max(surfacecolor)


def main():
    alpha = np.pi / 5
    x = np.linspace(-2, 2, 50)
    y = np.linspace(-2, 2, 50)
    x, y = np.meshgrid(x, y)
    z = -x * np.tan(alpha)

    def volume(x, y, z):
        return x * np.exp(-x ** 2 - y ** 2 - z ** 2)

    x = np.linspace(-2, 2, 50)
    y = np.linspace(-2, 2, 50)
    x, y = np.meshgrid(x, y)
    z = np.zeros(x.shape)
    surfcolor_z = volume(x, y, z)
    sminz, smaxz = get_lims_colors(surfcolor_z)

    slice_z = get_the_slice(x, y, z, surfcolor_z)

    x = np.linspace(-2, 2, 50)
    z = np.linspace(-2, 2, 50)
    x, z = np.meshgrid(x, y)
    y = -0.5 * np.ones(x.shape)
    surfcolor_y = volume(x, y, z)
    sminy, smaxy = get_lims_colors(surfcolor_y)
    vmin = min([sminz, sminy])
    vmax = max([smaxz, smaxy])
    #    slice_y = get_the_slice(x, y, z, surfcolor_y)

    axis = dict(
        showbackground=True,
        backgroundcolor="rgb(230, 230,230)",
        gridcolor="rgb(255, 255, 255)",
        zerolinecolor="rgb(255, 255, 255)",
    )

    layout = dict(
        title="Slices in volumetric data",
        width=700,
        height=700,
        scene=dict(
            xaxis=pgo.layout.scene.XAxis(axis),
            yaxis=pgo.layout.scene.YAxis(axis),
            zaxis=pgo.layout.scene.ZAxis(axis, range=[-2, 2]),
            aspectratio=dict(x=1, y=1, z=1),
        ),
    )

    surfcolor_obl = volume(x, y, z)

    smino, smaxo = get_lims_colors(surfcolor_obl)
    vmin = min([sminz, smino])
    vmax = max([smaxz, smaxo])

    slice_obl = get_the_slice(x, y, z, surfcolor_obl)
    slice_obl.update(cmin=vmin, cmax=vmax, showscale=True)

    slice_z.update(cmin=vmin, cmax=vmax)

    fig = pgo.Figure(data=[slice_z, slice_obl], layout=layout)

    plotly.offline.plot(fig, filename="Slice-volumetric-2.html")


if __name__ == "__main__":
    main()