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Masterprojekt/GHA_triaxial/gha1_approx.py
2026-02-08 16:28:59 +01:00

97 lines
3.2 KiB
Python

import numpy as np
from ellipsoide import EllipsoidTriaxial
from GHA_triaxial.gha1_ana import gha1_ana
from GHA_triaxial.utils import func_sigma_ell, louville_constant
import plotly.graph_objects as go
import winkelumrechnungen as wu
def gha1_approx(ell: EllipsoidTriaxial, p0: np.ndarray, alpha0: float, s: float, ds: float, all_points: bool = False) -> Tuple[NDArray, float] | Tuple[NDArray, float, NDArray]:
"""
Berechung einer Näherungslösung der ersten Hauptaufgabe
:param ell: Ellipsoid
:param p0: Anfangspunkt
:param alpha0: Azimut im Anfangspunkt
:param s: Strecke bis zum Endpunkt
:param ds: Länge einzelner Streckenelemente
:param all_points: Ausgabe aller Punkte als Array?
:return: Endpunkt, Azimut im Endpunkt, optional alle Punkte
"""
l0 = louville_constant(ell, p0, alpha0)
points = [p0]
alphas = [alpha0]
s_curr = 0.0
last_sigma = None
last_p = None
while s_curr < s:
ds_step = min(ds, s - s_curr)
if ds_step < 1e-8:
break
p1 = points[-1]
alpha1 = alphas[-1]
p, q = pq_ell(ell, p1)
if last_p is not None and np.dot(p, last_p) < 0:
p = -p
q = -q
sigma = p * sin(alpha1) + q * cos(alpha1)
if last_sigma is not None and np.dot(sigma, last_sigma) < 0:
sigma = -sigma
p2 = p1 + ds_step * sigma
p2 = ell.point_onto_ellipsoid(p2)
dalpha = 1e-6
l2 = louville_constant(ell, p2, alpha1)
dl_dalpha = (louville_constant(ell, p2, alpha1+dalpha) - l2) / dalpha
alpha2 = alpha1 + (l0 - l2) / dl_dalpha
points.append(p2)
alphas.append(alpha2)
ds_step = np.linalg.norm(p2 - p1)
s_curr += ds_step
last_sigma = sigma
pass
if all_points:
return points[-1], alphas[-1], np.array(points), np.array(alphas)
else:
return points[-1], alphas[-1]
def show_points(points: NDArray, p0: NDArray, p1: NDArray):
"""
Anzeigen der Punkte
:param points: Array aller approximierten Punkte
:param p0: Startpunkt
:param p1: wahrer Endpunkt
"""
fig = go.Figure()
fig.add_scatter3d(x=points[:, 0], y=points[:, 1], z=points[:, 2],
mode='lines', line=dict(color="red", width=3), name="Approx")
fig.add_scatter3d(x=[p0[0]], y=[p0[1]], z=[p0[2]],
mode='markers', marker=dict(color="green"), name="P0")
fig.add_scatter3d(x=[p1[0]], y=[p1[1]], z=[p1[2]],
mode='markers', marker=dict(color="green"), name="P1")
fig.update_layout(
scene=dict(xaxis_title='X [km]',
yaxis_title='Y [km]',
zaxis_title='Z [km]',
aspectmode='data'),
title="CHAMP")
fig.show()
if __name__ == '__main__':
ell = EllipsoidTriaxial.init_name("BursaSima1980round")
P0 = ell.ell2cart(wu.deg2rad(89), wu.deg2rad(1))
alpha0 = wu.deg2rad(2)
s = 200000
P1_app, alpha1_app, points, alphas = gha1_approx(ell, P0, alpha0, s, ds=100, all_points=True)
P1_ana, alpha1_ana = gha1_ana(ell, P0, alpha0, s, maxM=20, maxPartCircum=2)
print(np.linalg.norm(P1_app - P1_ana))
show_points(points, P0, P1_ana)