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pNbody/examples/ic/generate_galaxy.py
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generate_galaxy.py
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#!/usr/bin/env python
from pNbody import *
from pNbody import ic
from pNbody import libgrid
from pNbody import libutil
from pNbody import libdisk
#################################################################
# model parameters
#################################################################
Ntot = 2**19 # total number of particles
nf = 1 # particle number mutiplicative number (used to reduce noise)
eps = 0.25 # softening
# mass ratio between components
fm_gas = 1.
fm_disk = 5.
fm_bulge = 5.
fm_halo = 20.
# disk
M_disk = 40.
Hr_disk = 4.
Hz_disk = 0.3
fr_disk = 10.
fz_disk = 10.
# halo
M_halo = 300.
Hr_halo = 30.
fr_halo = 3.0
# bulge
M_bulge = 16.0
Hr_bulge = 1.4
fr_bulge = 5.0
# gas
M_gas = 8.
Hz_gas = 0.3
Rf = 40.
Hr_gas = Hr_halo - Hz_gas
rmax_gas = 3*Hr_halo
zmax_gas = 3*Hz_gas
#################################################################
# parameters for the velocities
#################################################################
ErrTolTheta = 0.5
AdaptativeSoftenning = False
###################################
# spherical components
###################################
# grid parameters halo
stats_name_halo = "stats_halo.dmp"
grmin_halo = 0 # grid minimal radius
grmax_halo = Hr_halo*fr_halo*1.05 # grid maximal radius
nr_halo = 64 # number of radial bins
eps_halo = eps
# transfert function
rc_halo = Hr_halo
g_halo = lambda r:log(r/rc_halo+1.)
gm_halo = lambda r:rc_halo*(exp(r)-1.)
# grid parameters bulge
stats_name_bulge = "stats_bulge.dmp"
grmin_bulge = 0 # grid minimal radius
grmax_bulge = Hr_halo*fr_halo*1.05 # grid maximal radius
nr_bulge = 64 # number of radial bins
eps_bulge = eps
# transfert function
rc_bulge = Hr_halo
g_bulge = lambda r:log(r/rc_bulge+1.)
gm_bulge = lambda r:rc_bulge*(exp(r)-1.)
###################################
# cylindrical components
###################################
# grid parameters disk
stats_name_disk = "stats_disk.dmp"
grmin_disk = 0. # minimal grid radius
grmax_disk = Hr_disk*fr_disk # maximal grid radius
gzmin_disk = -Hz_disk*fz_disk # minimal grid z
gzmax_disk = Hz_disk*fz_disk # maximal grid z
nr_disk = 32 # number of bins in r
nt_disk = 2 # number of bins in t
nz_disk = 64+1 # number of bins in z
# for an even value of nz, the potential is computed at z=0
# for an odd value of nz, the density is computed at z=0
eps_disk = eps
rc_disk = 3.0
g_disk = lambda r:log(r/rc_disk+1.)
gm_disk = lambda r:rc_disk*(exp(r)-1.)
mode_sigma_z = {"name":"jeans","param":None}
mode_sigma_r = {"name":"toomre","param":1.0}
mode_sigma_p = {"name":"epicyclic_approximation","param":None}
params_disk = [mode_sigma_z,mode_sigma_r,mode_sigma_p]
# grid parameters gas
stats_name_gas = "stats_gas.dmp"
grmin_gas = 0. # minimal grid radius
grmax_gas = rmax_gas*1.05 # maximal grid radius
gzmin_gas = -zmax_gas*1.05 # minimal grid z
gzmax_gas = zmax_gas*1.05 # maximal grid z
nr_gas = 32 # number of bins in r
nt_gas = 2 # number of bins in t
nz_gas = 64+1 # number of bins in z
# for an even value of nz, the potential is computed at z=0
# for an odd value of nz, the density is computed at z=0
eps_gas = eps
rc_gas = 3.0
g_gas = lambda r:log(r/rc_gas+1.)
gm_gas = lambda r:rc_gas*(exp(r)-1.)
mode_sigma_z = {"name":"jeans","param":None}
mode_sigma_r = {"name":"constant","param":0.1}
mode_sigma_p = {"name":"epicyclic_approximation","param":None}
params_gas = [mode_sigma_z,mode_sigma_r,mode_sigma_p]
#################################################################
# compute mass for each components
#################################################################
# ref mas of particles
m = ( M_disk/fm_disk + M_halo/fm_halo + M_bulge/fm_bulge + M_gas/fm_gas )/float(Ntot)
# distributes number of particles
N_gas = int( M_gas /(m*fm_gas) )
N_disk = int( M_disk /(m*fm_disk) )
N_bulge = int( M_bulge/(m*fm_bulge) )
N_halo = int( M_halo/(m*fm_halo) )
print "N_gas = %d"%N_gas
print "N_disk = %d"%N_disk
print "N_bulge = %d"%N_bulge
print "N_halo = %d"%N_halo
print "----------------------------"
print "N_tot = %d"%(N_gas+N_disk+N_bulge+N_halo)
print "----------------------------"
if nf > 1:
N_gas = int(nf*N_gas)
N_disk = int(nf*N_disk)
N_bulge = int(nf*N_bulge)
N_halo = int(nf*N_halo)
#################################################################
# generate models
#################################################################
#####################
# exponnential disk
#####################
nb_disk = None
if M_disk != 0.0:
print "generating disk..."
nb_disk = ic.expd(N_disk,Hr_disk,Hz_disk,fr_disk*Hr_disk,fz_disk*Hz_disk,irand=0,ftype='gadget')
nb_disk.set_tpe(2)
nb_disk.mass = (M_disk/N_disk) * ones(nb_disk.nbody).astype(float32)
nb_disk.rename('disk.dat')
nb_disk.write()
#####################
# halo
#####################
nb_halo = None
if M_halo != 0.0:
print "generating halo..."
nb_halo = ic.plummer(N_halo,1,1,1,Hr_halo,fr_halo*Hr_halo,vel='no',ftype='gadget')
nb_halo.set_tpe(1)
nb_halo.mass = (M_halo/N_halo) * ones(nb_halo.nbody).astype(float32)
nb_halo.rename('halo.dat')
nb_halo.write()
#####################
# bulge
#####################
nb_bulge = None
if M_bulge != 0.0:
print "generating bulge..."
nb_bulge = ic.plummer(N_bulge,1,1,1,Hr_bulge,fr_bulge*Hr_bulge,vel='no',ftype='gadget')
nb_bulge.set_tpe(3)
nb_bulge.mass = (M_bulge/N_bulge) * ones(nb_bulge.nbody).astype(float32)
nb_bulge.rename('bulge.dat')
nb_bulge.write()
#####################
# gas disk
#####################
nb_gas = None
if M_gas != 0.0:
print "generating gas..."
nb_gas = ic.miyamoto_nagai(N_gas,Hr_gas,Hz_gas,rmax_gas,zmax_gas,irand=-2,ftype='gadget')
nb_gas.set_tpe(0)
nb_gas.mass = (M_gas/N_gas) * ones(nb_gas.nbody).astype(float32)
nb_gas.rename('gas.dat')
nb_gas.write()
###############################################################
# merge all components
###############################################################
nb = Nbody(ftype='gadget')
if nb_disk != None:
nb = nb + nb_disk
if nb_halo != None:
nb = nb + nb_halo
if nb_bulge != None:
nb = nb + nb_bulge
if nb_gas != None:
nb = nb + nb_gas
nb.rename('snapnf.dat')
nb.write()
###############################################################
# compute velocities
###############################################################
if nb_disk != None:
print "------------------------"
print "disk velocities..."
print "------------------------"
nb_disk,phi,stats_disk = nb.Get_Velocities_From_Cylindrical_Grid(select='disk',disk=('disk','gas'),eps=eps_disk,nR=nr_disk,nz=nz_disk,nt=nt_disk,Rmax=grmax_disk,zmin=gzmin_disk,zmax=gzmax_disk,params=params_disk,Phi=None,g=g_disk,gm=gm_disk,ErrTolTheta=ErrTolTheta,AdaptativeSoftenning=AdaptativeSoftenning)
io.write_dmp(stats_name_disk,stats_disk)
r = stats_disk['R']
z = stats_disk['z']
dr = r[1]-r[0]
dz = z[nz_disk/2+1]-z[nz_disk/2]
print "disk : Delta R :",dr,"=",dr/eps_disk,"eps"
print "disk : Delta z :",dz,"=",dz/eps_disk,"eps"
# reduc
if nf>1:
nb_disk = nb_disk.reduc(nf,mass=True)
if nb_gas != None:
print "------------------------"
print "gas velocities..."
print "------------------------"
nb_gas,phi,stats_gas = nb.Get_Velocities_From_Cylindrical_Grid(select='gas',disk=('disk','gas'),eps=eps_gas,nR=nr_gas,nz=nz_gas,nt=nt_gas,Rmax=grmax_gas,zmin=gzmin_gas,zmax=gzmax_gas,params=params_gas,Phi=None,g=g_gas,gm=gm_gas,ErrTolTheta=ErrTolTheta,AdaptativeSoftenning=AdaptativeSoftenning)
io.write_dmp(stats_name_gas,stats_gas)
r = stats_gas['R']
z = stats_gas['z']
dr = r[1]-r[0]
dz = z[nz_gas/2+1]-z[nz_gas/2]
print "gas : Delta R :",dr,"=",dr/eps_gas,"eps"
print "gas : Delta z :",dz,"=",dz/eps_gas,"eps"
# reduc
if nf>1:
nb_gas = nb_gas.reduc(nf,mass=True)
if nb_bulge != None:
print "------------------------"
print "bulge velocities..."
print "------------------------"
nb_bulge,phi,stats_bulge = nb.Get_Velocities_From_Spherical_Grid(select='bulge',eps=eps_bulge,nr=nr_bulge,rmax=grmax_bulge,phi=None,g=g_bulge,gm=gm_bulge,UseTree=True,ErrTolTheta=ErrTolTheta)
io.write_dmp(stats_name_bulge,stats_bulge)
r = stats_bulge['r']
dr = r[1]-r[0]
print "bulge : Delta r :",dr,'=',dr/eps_bulge,"eps"
# reduc
if nf>1:
nb_bulge = nb_bulge.reduc(nf,mass=True)
if nb_halo != None:
print "------------------------"
print "halo velocities..."
print "------------------------"
nb_halo,phi,stats_halo = nb.Get_Velocities_From_Spherical_Grid(select='halo',eps=eps_halo,nr=nr_halo,rmax=grmax_halo,phi=None,g=g_halo,gm=gm_halo,UseTree=True,ErrTolTheta=ErrTolTheta)
io.write_dmp(stats_name_halo,stats_halo)
r = stats_halo['r']
dr = r[1]-r[0]
print "halo : Delta r :",dr,'=',dr/eps_halo,"eps"
# reduc
if nf>1:
nb_halo = nb_halo.reduc(nf,mass=True)
###############################################################
# recompose models and save it
###############################################################
nb = Nbody(ftype='gadget')
if nb_disk != None:
nb = nb + nb_disk
if nb_halo != None:
nb = nb + nb_halo
if nb_bulge != None:
nb = nb + nb_bulge
if nb_gas != None:
nb = nb + nb_gas
nb.rename('snap.dat')
nb.write()
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