MicroStructPy Logo

Python Script

The basename for this file is logo.py. The file can be run using this command:

microstructpy --demo=logo.py

The full text of the script is:

from __future__ import division

import os

import matplotlib.pyplot as plt
import numpy as np
from matplotlib import collections
from matplotlib.offsetbox import AnnotationBbox
from matplotlib.offsetbox import OffsetImage

import microstructpy as msp


def main(n_seeds, size_rng, pos_rng, k_lw):
    bkgrnd_color = 'black'
    line_color = (1, 1, 1, 1)  # white

    dpi = 300
    init_size = 2000
    logo_size = 1500
    favicon_size = 48

    logo_basename = 'logo.svg'
    favicon_basename = 'favicon.ico'
    social_basename = 'social.png'
    file_dir = os.path.dirname(os.path.realpath(__file__))
    path = os.path.join(file_dir, 'logo')
    if not os.path.exists(path):
        os.makedirs(path)
    print(path)
    logo_filename = os.path.join(path, logo_basename)
    pad_filename = os.path.join(path, 'pad_' + logo_basename)
    favicon_filename = os.path.join(path, favicon_basename)
    social_filename = os.path.join(path, social_basename)

    # Set Domain
    domain = msp.geometry.Circle()

    # Set Seed List
    np.random.seed(size_rng)
    rs = 0.3 * np.random.rand(n_seeds)

    factory = msp.seeding.Seed.factory
    seeds = msp.seeding.SeedList([factory('circle', r=r) for r in rs])
    seeds.position(domain, rng_seed=pos_rng)

    # Create the Poly Mesh
    pmesh = msp.meshing.PolyMesh.from_seeds(seeds, domain)

    # Create and Format the Figure
    plt.clf()
    plt.close('all')
    fig = plt.figure(figsize=(init_size / dpi, init_size / dpi), dpi=dpi)
    ax = plt.Axes(fig, [0., 0., 1., 1.])
    ax.set_axis_off()
    ax.get_xaxis().set_visible(False)
    ax.get_yaxis().set_visible(False)
    fig.add_axes(ax)

    # Plot the Domain
    domain.plot(ec='none', fc=bkgrnd_color)

    # Plot the Facets
    facet_colors = []
    for neigh_pair in pmesh.facet_neighbors:
        if min(neigh_pair) < 0:
            facet_colors.append('none')
        else:
            facet_colors.append(line_color)

    lw = k_lw * init_size / 100
    pmesh.plot_facets(colors=facet_colors, linewidth=lw, capstyle='round')

    pts = np.array(pmesh.points)
    rs = np.sqrt(np.sum(pts * pts, axis=1))
    mask = np.isclose(rs, 1)

    edges = []
    for facet in pmesh.facets:
        if np.sum(mask[facet]) != 1:
            continue

        edge = np.copy(pts[facet])
        if mask[facet[0]]:
            u = edge[0] - edge[1]
            u *= 1.1
            edge[0] = edge[1] + u
        else:
            u = edge[1] - edge[0]
            u *= 1.1
            edge[1] = edge[0] + u
        edges.append(edge)

    pc = collections.LineCollection(edges, color=line_color, linewidth=lw,
                                    capstyle='round')
    ax.add_collection(pc)

    # Format the Plot and Convert to Image Array
    plt.axis('square')
    plt.axis(1.01 * np.array([-1, 1, -1, 1]))
    fig.canvas.draw()

    plt_im = np.array(fig.canvas.get_renderer()._renderer)
    mask = plt_im[:, :, 0] > 0.5 * 255

    # Create the Logo
    logo_im = np.copy(plt_im)

    xx, yy = np.meshgrid(*[np.arange(n) for n in logo_im.shape])
    zz = - 0.2 * xx + 0.9 * yy
    ss = (zz - zz.min()) / (zz.max() - zz.min())

    c1 = [67, 206, 162]
    c2 = [24, 90, 157]

    logo_im[mask, -1] = 0  # transparent background

    # gradient
    for i in range(logo_im.shape[-1] - 1):
        logo_im[~mask, i] = (1 - ss[~mask]) * c1[i] + ss[~mask] * c2[i]

    inds = np.linspace(0, logo_im.shape[0] - 1, logo_size).astype('int')
    logo_im = logo_im[inds]
    logo_im = logo_im[:, inds]

    pad_w = logo_im.shape[0]
    pad_h = 0.5 * logo_im.shape[1]
    pad_shape = np.array([pad_w, pad_h, logo_im.shape[2]]).astype('int')
    logo_pad = np.zeros(pad_shape, dtype=logo_im.dtype)
    pad_im = np.concatenate((logo_pad, logo_im, logo_pad), axis=1)
    doc_im = np.concatenate((logo_pad, pad_im, logo_pad), axis=1)

    plt.imsave(logo_filename, logo_im, dpi=dpi)
    plt.imsave(logo_filename.replace('.svg', '.png'), logo_im, dpi=dpi)
    plt.imsave(pad_filename, pad_im, dpi=dpi)
    plt.imsave(pad_filename.replace('.svg', '.png'), doc_im, dpi=dpi)

    # Create the Favicon
    fav_im = np.copy(logo_im)
    inds = np.linspace(0, fav_im.shape[0] - 1, favicon_size).astype('int')
    fav_im = fav_im[inds]
    fav_im = fav_im[:, inds]

    plt.imsave(favicon_filename, fav_im, dpi=dpi, format='png')

    # Create the Social Banner
    fig_social, ax_social = plt.subplots()

    ax_social.set_xlim(0, 2)
    ax_social.set_ylim(0, 1)
    ax_social.set_aspect('equal')

    ax_social.set_axis_off()
    ax_social.get_xaxis().set_visible(False)
    ax_social.get_yaxis().set_visible(False)

    imagebox = OffsetImage(logo_im, zoom=0.05)
    ab = AnnotationBbox(imagebox, (1, 0.7), frameon=False)
    ax_social.add_artist(ab)
    ax_social.text(1, 0.35, 'MicroStructPy',
                   fontsize=20,
                   weight='bold',
                   horizontalalignment='center',
                   verticalalignment='center')
    ax_social.text(1, 0.23, 'Microstructure Mesh Generation in Python',
                   fontsize=10,
                   horizontalalignment='center',
                   verticalalignment='center')
    plt.draw()
    plt.savefig(social_filename, bbox_inches='tight')
    plt.close('all')


if __name__ == '__main__':
    n_seeds = 14
    size_rng = 4
    pos_rng = 7
    k_lw = 1.1

    main(n_seeds, size_rng, pos_rng, k_lw)

Domain

The domain of the microstructure is a Circle. Without arguments, the circle’s center is (0, 0) and side length is 1.

Seeds

The seeds are 14 circles with radii uniformly distributed from 0 to 0.3. Calling the position() method positions the points according to random uniform distributions in the domain.

Polygon Mesh

A polygon mesh is created from the list of seed points using the from_seeds() class method. The mesh is plotted and saved into a PNG file in the remaining lines of the script.

Plot Logo

The edges in the polygonal mesh are plotted white on a black background. This image is converted into a mask and the white pixels are converted into transparent pixels. The remaining pixels are colored with a linear gradient between two colors. This image is saved in padded and tight versions, as well as a favicon for the HTML documentation. The logo that results is shown in Fig. 23.

Fig. 23 MicroStructPy logo.