Example Usage of spack

This is an ipython notebook in spack/docs/example-usage.ipynb, demonstrating how to use spack.

First, we import our modules:

import spack
from math import pi

Now we put in some data.

The data below is from a simple packing I made using pyparm.packmin. Normally you’d load your own data from a file.

L = 2.0066668050219723
diameters = [ 0.96,  0.97,  0.98,  0.99,  1.  ,  1.01,  1.02,  1.03,  1.04]
locs = [[ 1.40776762,  1.26647724,  0.73389219],
        [ 0.58704249,  2.11399   ,  1.52956579],
        [ 1.75917911,  0.54290089,  1.27577478],
        [ 2.13750384,  0.87508242,  0.21938647],
        [ 1.07283961,  0.87692084,  1.9060841 ],
        [ 0.09550267,  1.94404465,  0.56463369],
        [ 1.07636871,  2.1942971 ,  0.63752152],
        [ 0.49922725,  1.20002224,  1.13360082],
        [-0.27724757,  1.62152603,  1.67262247]]

Now we make the packing:

pack = spack.Packing(locs, diameters, L=L)

What does it look like?

size = 400
sc = pack.scene(rot=pi/4, camera_dist=2, cmap='autumn', bgcolor=[1,1,1])
sc.render('ipython', width=size, height=size, antialiasing=0.001)

Let’s make a movie!

from moviepy.editor import VideoClip
import moviepy.editor as mpy

duration = 10
def make_frame(t):
    return (
                pack.scene(rot=(t/duration + .125)*2.*pi,
                           camera_dist=2, cmap='autumn', bgcolor=[1,1,1])
                .render(width=size, height=size, antialiasing=0.001)
            )
vc = VideoClip(make_frame, duration=duration)

Write the movie to file. This takes about 10 minutes on my machine to render all 240 frames, but it does give you some pretty spiffy output.

vc.write_gif("example-packing.gif",fps=24)

[MoviePy] >>>> Building file example-packing.gif
[MoviePy] Generating GIF frames...
[MoviePy] Optimizing the GIF with ImageMagick...
[MoviePy] >>>> File example-packing.gif is ready !

And display the movie, in an ipython notebook.

from IPython.display import Image
Image(url="example-packing.gif")