import frackit.geometry as geometry
import random
import math
# we use the unit cube as domain
box = geometry.Box(xmin=0.0, ymin=0.0, zmin=0.0,
xmax=1.0, ymax=1.0, zmax=1.0)
# we sample points uniformly within the domain
from frackit.sampling import makeUniformPointSampler
# returns a sampler from a gaussian distribution with mean and std deviation
def gaussianSampler(mean, stdDev):
def sample(): return random.gauss(mean, stdDev)
return sample
# returns a sampler from a uniform distribution between min and max
def uniformSampler(min, max):
def sample(): return random.uniform(min, max)
return sample
# we sample quadrilaterals within the box with gaussian distributions for the parameters
from frackit.sampling import QuadrilateralSampler as QuadSampler
quadSampler1 = QuadSampler(pointSampler = makeUniformPointSampler(box),
strikeAngleSampler = gaussianSampler(math.radians(45.0), math.radians(5.0)),
dipAngleSampler = gaussianSampler(math.radians(90.0), math.radians(5.0)),
strikeLengthSampler = uniformSampler(0.4, 0.8),
dipLengthSampler = uniformSampler(0.4, 0.8))
# sampler for quadrilaterals of the secondary orientation
quadSampler2 = QuadSampler(pointSampler = makeUniformPointSampler(box),
strikeAngleSampler = gaussianSampler(math.radians(0.0), math.radians(5.0)),
dipAngleSampler = gaussianSampler(math.radians(0.0), math.radians(5.0)),
strikeLengthSampler = uniformSampler(0.4, 0.8),
dipLengthSampler = uniformSampler(0.4, 0.8))
# We want to enforce some constraints on the set of quadrilaterals.
# In particular, for entities of the same set we want a minimum spacing
# distance of 5cm, and the quadrilaterals must not intersect in angles
# less than 30°. Moreover, if they intersect, we don't want intersection
# edges whose length is smaller than 5cm, and, the intersection should not
# be too close to the boundary of one of two intersecting quadrilaterals. Here: 5cm.
from frackit.entitynetwork import EntityNetworkConstraints
constraintsOnSelf = EntityNetworkConstraints()
constraintsOnSelf.setMinDistance(0.05)
constraintsOnSelf.setMinIntersectingAngle(math.radians(30.0))
constraintsOnSelf.setMinIntersectionMagnitude(0.05)
constraintsOnSelf.setMinIntersectionDistance(0.05)
# with respect to entities of the other set, we want to have larger intersection angles
constraintsOnOther = EntityNetworkConstraints()
constraintsOnOther.setMinDistance(0.05)
constraintsOnOther.setMinIntersectingAngle(math.radians(40.0))
constraintsOnOther.setMinIntersectionMagnitude(0.05)
constraintsOnOther.setMinIntersectionDistance(0.05)
# we use unique identifiers for the entities of the two orientations
from frackit.common import Id
idSet1 = Id(1)
idSet2 = Id(2)
# use the status class to define when to stop sampling
from frackit.sampling import SamplingStatus
status = SamplingStatus()
status.setTargetCount(idSet1, 15) # we want 15 entities in each set
status.setTargetCount(idSet2, 15) # we want 15 entities in each set
# start sampling into set 1 and keep alternating
sampleIntoSet1 = True
# lists to store the sampled entities
entities1 = []
entities2 = []
print("\n --- Start entity sampling ---\n")
while not status.finished():
# sample a quadrilateral, alternating between sampler 1 and sampler 2
quad = quadSampler1() if sampleIntoSet1 else quadSampler2()
entitySet = entities1 if sampleIntoSet1 else entities2
otherEntitySet = entities2 if sampleIntoSet1 else entities1
# skip the rest if constraints are violated
if not constraintsOnSelf.evaluate(entitySet, quad):
status.increaseRejectedCounter()
continue
# skip the rest if constraints are violated
if not constraintsOnOther.evaluate(otherEntitySet, quad):
status.increaseRejectedCounter()
continue
# the entity is admissible
entitySet.append(quad)
id = idSet1 if sampleIntoSet1 else idSet2
status.increaseCounter(id)
status.print()
# sample into other set the next time
sampleIntoSet1 = not sampleIntoSet1
print("\n --- Finished entity sampling ---\n")
# We can now create an entity network from the two sets
from frackit.entitynetwork import EntityNetworkBuilder
builder = EntityNetworkBuilder()
builder.addEntities(entities1)
builder.addEntities(entities2)
# let the builder construct the network and write it to gmsh file format
print("\n --- Constructing entity network from the raw entities ---\n")
network = builder.build()
print("\n --- Writing .geo file ---\n")
from frackit.io import GmshWriter
writer = GmshWriter(network)
writer.setMeshSize(GmshWriter.GeometryTag.entity, 0.1)
writer.write("network") # filename of the .geo files (will add extension .geo automatically)
print("\n --- Finished writing .geo file ---\n")