example.py

'''
tester for topology optimization code
'''

import numpy as np
import math
import matplotlib.pyplot as plt

from loads import HalfBeam
from constraints import DensityConstraint
from fesolvers import LilFESolver, CooFESolver
from topopt import Topopt

if __name__ == "__main__":
    # material properties
    young = 1
    poisson = 0.3

    # constraints
    volfrac = 0.4
    xmin = 0.001
    xmax = 1.0

    # input parameters
    nelx = 180
    nely = 60

    penal = 3.0
    rmin = 5.4

    delta = 0.02
    loopy = math.inf

    # loading/problem
    load = HalfBeam(nelx, nely)

    # constraints
    density_constraint = DensityConstraint(volume_frac = volfrac, density_min = xmin, density_max = xmax)

    # optimizer
    verbose = True
    fesolver = CooFESolver(verbose = verbose)
    optimizer = Topopt(fesolver, young, poisson, verbose = verbose)

    # compute
    history = False
    x = optimizer.init(load, density_constraint)
    x, x_more = optimizer.layout(load, density_constraint, x, penal, rmin, delta, loopy, history)

    if history:
        x_history = x_more
        loop = len(x_history)
    else:    
        loop = x_more
        x_history = None

    # save
    if x_history:
        # import scipy.misc
        # sequence = [scipy.misc.toimage(x, cmin=0, cmax=1) for x in x_history]
        import imageio
        imageio.mimsave('topopt.gif', x_history)

    # plot
    plt.figure()
    plt.imshow(x, cmap=plt.cm.gray)
    plt.title(str(loop) + ' loops')
    plt.xticks([])
    plt.yticks([])
    plt.show()