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87 lines
2.6 KiB
Python
87 lines
2.6 KiB
Python
#!/usr/bin/env python
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"""
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Main: Computes Poincaré Sections (Linear Algorithm)
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Computes the Poincaré Sections with a linear algorithm
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(i.e. no parallel computing).
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@ Author: Moussouni, Yaël (MSc student) & Bhat, Junaid Ramzan (MSc student)
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@ Institution: Université de Strasbourg, CNRS, Observatoire astronomique
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de Strasbourg, UMR 7550, F-67000 Strasbourg, France
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@ Date: 2024-11-29
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"""
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import numpy as np
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import potentials as pot
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import integrator as itg
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import initial_conditions as init
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import poincare_sections as pcs
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# Parameters
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OUT_DIR = "./Output/"
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FILENAME_PREFIX = "poincare_sections_linear_"
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EXTENSION = ".csv"
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DEFAULT_N_iter = 30000
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DEFAULT_N_part = 100
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DEFAULT_h = 0.01
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E_all = np.array([1/100, 1/12, 1/10, 1/8, 1/6])
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text_E = ["1/100", "1/12", "1/10", "1/8", "1/6"]
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def compute_poincare_sections_linear(E: float,
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N_iter: int = DEFAULT_N_iter,
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N_part: int = DEFAULT_N_part,
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h: float = DEFAULT_h) -> tuple:
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"""
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Computes the Poincaré sections for a given energy E.
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@params:
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- E: the total energy of each particles
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- N_iter: the number of iteration
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- N_part: the number of particles
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- h: integration steps
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@returns:
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- y_section, v_section: arrays containing the y and v coordinates of
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the Poincaré sections
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"""
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W_all_part = init.n_energy_part(pot.hh_potential, N_part, E)
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y_section = []
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v_section = []
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for i in range(N_part):
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W_part = W_all_part[:,:,i]
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# Perform integration
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t_part, coord_part = itg.rk4(0, W_part, h, N_inter, pot.hh_evolution)
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# Extract positions and velocities
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x_part = coord_part[:, 0, 0]
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y_part = coord_part[:, 0, 1]
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u_part = coord_part[:, 1, 0]
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v_part = coord_part[:, 1, 1]
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# Find Poincaré section points for the current initial condition
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y_pcs, v_pcs = pcs.pcs_find_legacy(x_part, y_part, u_part, v_part)
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# The legacy is important here, the algorithm is the same but the
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# data format is different...
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# Append the current Poincaré section points to the overall lists
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y_section += y_pcs
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v_section += v_pcs
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return y_section, v_section
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if __name__ == "__main__":
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y_section_all = []
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v_section_all = []
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for i in range(len(E_all)):
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y_section, v_section = compute_poincare_sections_linear(E_all[i])
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section = np.array([y_section, v_section])
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filename = OUT_DIR + FILENAME_PREFIX\
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+ str(text_E[i][2:]) + EXTENSION
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np.savetxt(filename, section)
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