mirror of https://github.com/ArduPilot/ardupilot
99 lines
2.6 KiB
Python
Executable File
99 lines
2.6 KiB
Python
Executable File
#!/usr/bin/env python
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'''
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generate field tables from IGRF12
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'''
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import pyigrf12 as igrf
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import numpy as np
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import datetime
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import os.path
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import sys
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from math import sqrt, pi, atan2, asin
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if not os.path.isfile("AP_Declination.h"):
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print("Please run this tool from the AP_Declination directory")
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sys.exit(1)
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def field_to_angles(x, y, z):
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intensity = sqrt(x**2+y**2+z**2)
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r2d = 180.0 / pi
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declination = r2d * atan2(y, x)
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inclination = r2d * asin(z / intensity)
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return [intensity, inclination, declination]
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isv = 0
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date = datetime.datetime.now()
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itype = 1
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alt = 0.0
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SAMPLING_RES = 10
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SAMPLING_MIN_LAT = -90
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SAMPLING_MAX_LAT = 90
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SAMPLING_MIN_LON = -180
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SAMPLING_MAX_LON = 180
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NUM_LAT = 1 + (SAMPLING_MAX_LAT - SAMPLING_MIN_LAT) / SAMPLING_RES
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NUM_LON = 1 + (SAMPLING_MAX_LON - SAMPLING_MIN_LON) / SAMPLING_RES
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intensity_table = np.empty((NUM_LAT, NUM_LON))
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inclination_table = np.empty((NUM_LAT, NUM_LON))
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declination_table = np.empty((NUM_LAT, NUM_LON))
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for i in range(NUM_LAT):
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for j in range(NUM_LON):
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lat = SAMPLING_MIN_LAT + i*SAMPLING_RES
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lon = SAMPLING_MIN_LON + j*SAMPLING_RES
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x, y, z, f, d = igrf.gridigrf12(date, isv, itype, alt, lat, lon)
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intensity, I, D = field_to_angles(x, y, z)
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intensity_table[i][j] = intensity * 0.00001
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inclination_table[i][j] = I
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declination_table[i][j] = D
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tfile = open("tables.cpp", 'w')
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tfile.write('''// this is an auto-generated file from the IGRF tables. Do not edit
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// To re-generate run generate/generate.py
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#include "AP_Declination.h"
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''')
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tfile.write('''
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const float AP_Declination::SAMPLING_RES = %u;
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const float AP_Declination::SAMPLING_MIN_LAT = %u;
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const float AP_Declination::SAMPLING_MAX_LAT = %u;
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const float AP_Declination::SAMPLING_MIN_LON = %u;
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const float AP_Declination::SAMPLING_MAX_LON = %u;
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''' % (SAMPLING_RES,
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SAMPLING_MIN_LAT,
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SAMPLING_MAX_LAT,
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SAMPLING_MIN_LON,
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SAMPLING_MAX_LON))
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def write_table(name, table):
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'''write one table'''
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tfile.write("const float AP_Declination::%s[%u][%u] = {\n" %
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(name, NUM_LAT, NUM_LON))
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for i in range(NUM_LAT):
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tfile.write(" {")
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for j in range(NUM_LON):
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tfile.write("%.5f" % table[i][j])
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if j != NUM_LON-1:
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tfile.write(",")
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tfile.write("}")
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if i != NUM_LAT-1:
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tfile.write(",")
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tfile.write("\n")
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tfile.write("};\n\n")
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write_table('declination_table', declination_table)
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write_table('inclination_table', inclination_table)
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write_table('intensity_table', intensity_table)
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tfile.close()
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