def __init__(self, r, gridsize, spin, cells, tilt, landr, dt, atmdt, lifedt):
"""Create a simulation for a planet with the given characteristics. """
self._timing = Timing()
initt = self._timing.routine('simulation setup')
self.spin, self.cells, self.tilt = spin, cells, tilt
# max speed is 100km per million years
self._dp = 100.0/r * dt
self._build = dt/5.0
self._erode = dt
tilearea = 4 * pi * r**2
initt.start('building grid')
self._initgrid(gridsize)
self.tiles = {}
for v in self._grid.faces:
x, y, z = v
lat = 180/pi * atan2(z, sqrt(x*x + y*y))
lon = 180/pi * atan2(y, x)
self.tiles[v] = Tile(lat, lon)
initt.start('building indexes')
self.initindexes()
initt.start('creating initial landmass')
tilearea /= len(self._indexedtiles)
# the numerator of the split probability, where
# the number of tiles in the shape is the denomenator:
# a 50M km^2 continent has a 50/50 chance of splitting in a given step
self._splitnum = 25e6/tilearea
# initial location
p = [random.uniform(-1, 1) for i in range(3)]
p /= norm(p)
# 0 velocity vector
v = (0, 0, 0)
# orienting point
o = [0, 0, 0]
mini = min(range(len(p)), key=lambda i: abs(p[i]))
o[mini] = 1 if p[mini] < 0 else -1
shape = SphericalPolygon([rotate(rotate(p, o, landr*random.uniform(0.9,1.1)), p, th)
for th in [i*pi/8 for i in range(16)]])
self._shapes = [Group([t for t in self.tiles.values() if shape.contains(t.vector)], v)]
# initial landmass starts at elevation based on distance from center
c = self._indexedtiles[self._index.nearest(p)[0]]
r2 = landr*landr
# on land, one random tile is the center of a felsic chunk
f = random.choice(self._shapes[0].tiles)
for t in self._indexedtiles:
if t in self._shapes[0].tiles:
dc = t.distance(c)
df = t.distance(f)
r = igneous.extrusive(max(0.5, 1 - df*df/r2))
h = 1 - dc*dc/r2
t.emptyland(r, h)
else:
t.emptyocean(self.seafloor())
for t in self.tiles.values():
t.climate = t.seasons = None
initt.done()
self._atmosphereticks = atmdt / dt
self._lifeticks = lifedt / dt
self._climatemappings = {}
self._climateprof = None
self.dirty = True
def seafloor():
return igneous.extrusive(0.5)
def __init__(self, r, dt):
"""Create a simulation for a planet of radius r km and timesteps of dt
million years.
"""
self._timing = Timing()
initt = self._timing.routine('simulation setup')
# max speed is 100km per million years
self._dp = 100.0/r * dt
self._build = dt/5.0
self._erode = dt
tilearea = 4 * pi * r**2
initt.start('building grid')
grid = Grid()
while grid.size < 6:
grid = Grid(grid)
grid.populate()
self._grid = grid
self.tiles = {}
for v in self._grid.faces:
x, y, z = v
lat = 180/pi * atan2(y, sqrt(x*x + z*z))
lon = 180/pi * atan2(-x, z)
self.tiles[v] = Tile(lat, lon)
initt.start('building indexes')
self.initindexes()
initt.start('creating initial landmass')
tilearea /= len(self._indexedtiles)
# the numerator of the split probability, where
# the number of tiles in the shape is the denomenator:
# a 50M km^2 continent has a 50/50 chance of splitting in a given step
self._splitnum = 25e6/tilearea
# initial location
p = (0, 1, 0)
# 0 velocity vector
v = (0, 0, 0)
# orienting point
o = (1, 0, 0)
r = 1.145
shape = [(r*random.uniform(0.9,1.1)*cos(th),
r*random.uniform(0.9,1.1)*sin(th))
for th in [i*pi/8 for i in range(16)]]
shape = Shape(shape, p, o, v).projection()
self._shapes = [Group([t for t in self.tiles.itervalues() if shape.contains(t.vector)], v)]
# initial landmass starts at elevation based on distance from center
c = self._indexedtiles[self._index.nearest(p)[0]]
r2 = r*r
# on land, one random tile is the center of a felsic chunk
f = random.choice(self._shapes[0].tiles)
for t in self._indexedtiles:
if t in self._shapes[0].tiles:
dc = t.distance(c)
df = t.distance(f)
r = igneous.extrusive(max(0.5, 1 - df*df/r2))
h = 1 - dc*dc/r2
t.emptyland(r, h)
else:
t.emptyocean(self.seafloor())
for t in self.tiles.itervalues():
t.climate = None
initt.done()
self._atmosphere = self._life = False
self._climatemappings = {}
self._climateprof = None
self.dirty = True