74 lines
2.7 KiB
Python
74 lines
2.7 KiB
Python
import numpy as np
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import argparse
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def gen_plum(N, seed=None, RMAX=10):
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if not seed is None: np.random.seed(seed)
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particle_list = np.zeros((N,6))
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i = 0
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while (i < N):
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X1, X2, X3 = np.random.random(3)
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R = 1/np.sqrt(X1**(-2/3) - 1)
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if (R > RMAX): continue
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Z = (1 - 2*X2)*R
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X = np.sqrt(R**2 - Z**2) * np.cos(2*np.pi*X3)
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Y = np.sqrt(R**2 - Z**2) * np.sin(2*np.pi*X3)
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Ve = np.sqrt(2)*(1.0 + R**2)**(-0.25);
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X4, X5 = 0, 0
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while 0.1*X5 >= X4**2*(1-X4**2)**3.5:
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X4, X5 = np.random.random(2)
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V = Ve*X4
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X6, X7 = np.random.random(2)
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Vz = (1 - 2*X6)*V;
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Vx = np.sqrt(V**2 - Vz**2) * np.cos(2*np.pi*X7);
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Vy = np.sqrt(V**2 - Vz**2) * np.sin(2*np.pi*X7);
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X, Y, Z = np.array([X, Y, Z])*3*np.pi/16
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Vx, Vy, Vz = np.array([Vx, Vy, Vz])/np.sqrt(3*np.pi/16)
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particle_list[i,:] = [X, Y, Z, Vx, Vy, Vz]
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i += 1
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return particle_list
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parser = argparse.ArgumentParser(description='Process some integers.')
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parser.add_argument('N', type=str, help='The number of particles (follow by k to multiply by 1024)')
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parser.add_argument('--seed', type=int, default=42, help='Random seed')
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parser.add_argument('--eps', type=np.double, default=1E-4, help='Plummer softening parameter (can be even 0)')
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parser.add_argument('--t_end', type=np.double, default=4, help='end time of calculation')
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parser.add_argument('--dt_disk', type=np.double, default=1, help='interval of snapshot files output (0xxx.dat)')
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parser.add_argument('--dt_contr', type=np.double, default=.125, help='interval for the energy control output (contr.dat)')
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parser.add_argument('--dt_bh', type=np.double, default=.125, help='interval for BH output (bh.dat & bh_nb.dat)')
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parser.add_argument('--eta', type=np.double, default=.01, help='parameter for timestep determination (0.02 or 0.01)')
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args = parser.parse_args()
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try:
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N = int(args.N)
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except ValueError:
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if args.N[-1]=='k': N = int(args.N[:-1])*1024
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else: raise ValueError('Unable to parse N.')
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f = open('phi-GRAPE.cfg', 'w')
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f.write('%.4E %.4E %.4E %.4E %.4E %.4E data.con\n' % (args.eps, args.t_end, args.dt_disk, args.dt_contr, args.dt_bh, args.eta))
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f.close()
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particle_list = gen_plum(N)
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m = np.empty(N)
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m[:] = 1/N
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f = open('data.con', 'w')
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f.write('000000\n')
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f.write('%d\n' % N)
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f.write('0.0000000000E+00\n')
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for i in range(N):
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f.write('%06d%14.6e%14.6e%14.6e%14.6e%14.6e%14.6e%14.6e\n' % (i, m[i], particle_list[i,0], particle_list[i,1], particle_list[i,2], particle_list[i,3], particle_list[i,4], particle_list[i,5]))
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f.close()
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f = open('grapite.mask', 'w')
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for i in range(N):
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f.write('%06d %d\n' % (i, 0))
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f.close()
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