DAMASK_EICMD/processing/pre/seeds_fromRandom.py

166 lines
7.1 KiB
Python
Executable File

#!/usr/bin/env python3
import os
import sys
from optparse import OptionParser,OptionGroup
import numpy as np
from scipy import spatial
import damask
scriptName = os.path.splitext(os.path.basename(__file__))[0]
scriptID = ' '.join([scriptName,damask.version])
# --------------------------------------------------------------------
# MAIN
# --------------------------------------------------------------------
parser = OptionParser(option_class=damask.extendableOption, usage='%prog options', description = """
Distribute given number of points randomly within rectangular cuboid.
Reports positions with random crystal orientations in seeds file format to STDOUT.
""", version = scriptID)
parser.add_option('-N',
dest = 'N',
type = 'int', metavar = 'int',
help = 'number of seed points [%default]')
parser.add_option('-s',
'--size',
dest = 'size',
type = 'float', nargs = 3, metavar = 'float float float',
help='size x,y,z of unit cube to fill %default')
parser.add_option('-g',
'--grid',
dest = 'grid',
type = 'int', nargs = 3, metavar = 'int int int',
help='min a,b,c grid of hexahedral box %default')
parser.add_option('-m',
'--microstructure',
dest = 'microstructure',
type = 'int', metavar = 'int',
help = 'first microstructure index [%default]')
parser.add_option('-r',
'--rnd',
dest = 'randomSeed', type = 'int', metavar = 'int',
help = 'seed of random number generator [%default]')
group = OptionGroup(parser, "Laguerre Tessellation",
"Parameters determining shape of weight distribution of seed points"
)
group.add_option( '-w',
'--weights',
action = 'store_true',
dest = 'weights',
help = 'assign random weights to seed points for Laguerre tessellation [%default]')
group.add_option( '--max',
dest = 'max',
type = 'float', metavar = 'float',
help = 'max of uniform distribution for weights [%default]')
group.add_option( '--mean',
dest = 'mean',
type = 'float', metavar = 'float',
help = 'mean of normal distribution for weights [%default]')
group.add_option( '--sigma',
dest = 'sigma',
type = 'float', metavar = 'float',
help='standard deviation of normal distribution for weights [%default]')
parser.add_option_group(group)
group = OptionGroup(parser, "Selective Seeding",
"More uniform distribution of seed points using Mitchell's Best Candidate Algorithm"
)
group.add_option( '--selective',
action = 'store_true',
dest = 'selective',
help = 'selective picking of seed points from random seed points')
group.add_option( '--distance',
dest = 'distance',
type = 'float', metavar = 'float',
help = 'minimum distance to next neighbor [%default]')
group.add_option( '--numCandidates',
dest = 'numCandidates',
type = 'int', metavar = 'int',
help = 'size of point group to select best distance from [%default]')
parser.add_option_group(group)
parser.set_defaults(randomSeed = None,
grid = (16,16,16),
size = (1.0,1.0,1.0),
N = 20,
weights = False,
max = 0.0,
mean = 0.2,
sigma = 0.05,
microstructure = 1,
selective = False,
distance = 0.2,
numCandidates = 10,
)
(options,filenames) = parser.parse_args()
if filenames == []: filenames = [None]
size = np.array(options.size)
grid = np.array(options.grid)
np.random.seed(int(os.urandom(4).hex(),16) if options.randomSeed is None else options.randomSeed)
for name in filenames:
damask.util.report(scriptName,name)
if options.N > np.prod(grid):
damask.util.croak('More seeds than grid positions.')
sys.exit()
if options.selective and options.distance < min(size/grid):
damask.util.croak('Distance must be larger than grid spacing.')
sys.exit()
if options.selective and options.distance**3*options.N > 0.5*np.prod(size):
damask.util.croak('Number of seeds for given size and distance should be < {}.'\
.format(int(0.5*np.prod(size)/options.distance**3)))
eulers = np.random.rand(options.N,3) # create random Euler triplets
eulers[:,0] *= 360.0 # phi_1 is uniformly distributed
eulers[:,1] = np.degrees(np.arccos(2*eulers[:,1]-1.0)) # cos(Phi) is uniformly distributed
eulers[:,2] *= 360.0 # phi_2 is uniformly distributed
if not options.selective:
coords = damask.grid_filters.cell_coord0(grid,size).reshape(-1,3,order='F')
seeds = coords[np.random.choice(np.prod(grid), options.N, replace=False)] \
+ np.broadcast_to(size/grid,(options.N,3))*(np.random.rand(options.N,3)*.5-.25) # wobble without leaving grid
else:
seeds = np.empty((options.N,3))
seeds[0] = np.random.random(3) * size
i = 1
progress = damask.util._ProgressBar(options.N,'',50)
while i < options.N:
candidates = np.random.rand(options.numCandidates,3)*np.broadcast_to(size,(options.numCandidates,3))
tree = spatial.cKDTree(seeds[:i])
distances, dev_null = tree.query(candidates)
best = distances.argmax()
if distances[best] > options.distance: # require minimum separation
seeds[i] = candidates[best] # maximum separation to existing point cloud
i += 1
progress.update(i)
comments = [scriptID + ' ' + ' '.join(sys.argv[1:]),
'grid\ta {}\tb {}\tc {}'.format(*grid),
'size\tx {}\ty {}\tz {}'.format(*size),
'randomSeed\t{}'.format(options.randomSeed),
]
table = damask.Table(np.hstack((seeds,eulers)),{'pos':(3,),'euler':(3,)},comments)
table.add('microstructure',np.arange(options.microstructure,options.microstructure + options.N,dtype=int))
if options.weights:
weights = np.random.uniform(low = 0, high = options.max, size = options.N) if options.max > 0.0 \
else np.random.normal(loc = options.mean, scale = options.sigma, size = options.N)
table.add('weight',weights)
table.to_file(sys.stdout if name is None else name)