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AP_Declination: 2to3, IGRF API update

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use built-in IGRF total, incl, decl computations
This commit is contained in:
scivision 2018-05-23 05:30:57 -04:00 committed by Andrew Tridgell
parent ebcdf4c9c6
commit 67a503d5d8
1 changed files with 53 additions and 65 deletions
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118
libraries/AP_Declination/generate/generate.py
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@ -6,93 +6,81 @@ generate field tables from IGRF12
import pyigrf12 as igrf
import numpy as np
import datetime
import os.path
import sys
from math import sqrt, pi, atan2, asin
from pathlib import Path
if not os.path.isfile("AP_Declination.h"):
print("Please run this tool from the AP_Declination directory")
sys.exit(1)
if not Path("AP_Declination.h").is_file():
raise OSError("Please run this tool from the AP_Declination directory")
def field_to_angles(x, y, z):
intensity = sqrt(x**2+y**2+z**2)
r2d = 180.0 / pi
declination = r2d * atan2(y, x)
inclination = r2d * asin(z / intensity)
return [intensity, inclination, declination]
def write_table(f,name, table):
'''write one table'''
f.write("const float AP_Declination::%s[%u][%u] = {\n" %
(name, NUM_LAT, NUM_LON))
for i in range(NUM_LAT):
f.write(" {")
for j in range(NUM_LON):
f.write("%.5f" % table[i][j])
if j != NUM_LON-1:
f.write(",")
f.write("}")
if i != NUM_LAT-1:
f.write(",")
f.write("\n")
f.write("};\n\n")
isv = 0
date = datetime.datetime.now()
itype = 1
alt = 0.0
SAMPLING_RES = 10
SAMPLING_MIN_LAT = -90
SAMPLING_MAX_LAT = 90
SAMPLING_MIN_LON = -180
SAMPLING_MAX_LON = 180
NUM_LAT = 1 + (SAMPLING_MAX_LAT - SAMPLING_MIN_LAT) / SAMPLING_RES
NUM_LON = 1 + (SAMPLING_MAX_LON - SAMPLING_MIN_LON) / SAMPLING_RES
if __name__ == '__main__':
intensity_table = np.empty((NUM_LAT, NUM_LON))
inclination_table = np.empty((NUM_LAT, NUM_LON))
declination_table = np.empty((NUM_LAT, NUM_LON))
date = datetime.datetime.now()
# date = datetime.date(2018,2,20)
for i in range(NUM_LAT):
for j in range(NUM_LON):
lat = SAMPLING_MIN_LAT + i*SAMPLING_RES
lon = SAMPLING_MIN_LON + j*SAMPLING_RES
x, y, z, f, d = igrf.gridigrf12(date, isv, itype, alt, lat, lon)
intensity, I, D = field_to_angles(x, y, z)
intensity_table[i][j] = intensity * 0.00001
inclination_table[i][j] = I
declination_table[i][j] = D
SAMPLING_RES = 10
SAMPLING_MIN_LAT = -90
SAMPLING_MAX_LAT = 90
SAMPLING_MIN_LON = -180
SAMPLING_MAX_LON = 180
tfile = open("tables.cpp", 'w')
tfile.write('''// this is an auto-generated file from the IGRF tables. Do not edit
lats = np.arange(SAMPLING_MIN_LAT, SAMPLING_MAX_LAT+SAMPLING_RES, SAMPLING_RES)
lons = np.arange(SAMPLING_MIN_LON, SAMPLING_MAX_LON+SAMPLING_RES, SAMPLING_RES)
NUM_LAT = lats.size
NUM_LON = lons.size
intensity_table = np.empty((NUM_LAT, NUM_LON))
inclination_table = np.empty((NUM_LAT, NUM_LON))
declination_table = np.empty((NUM_LAT, NUM_LON))
for i,lat in enumerate(lats):
for j,lon in enumerate(lons):
mag = igrf.igrf(date=date, glat=lat, glon=lon, alt=0., isv=0, itype=1)
intensity_table[i][j] = mag.total/1e5
inclination_table[i][j] = mag.incl
declination_table[i][j] = mag.decl
with open("tables.cpp", 'w') as f:
f.write('''// this is an auto-generated file from the IGRF tables. Do not edit
// To re-generate run generate/generate.py
#include "AP_Declination.h"
''')
tfile.write('''
const float AP_Declination::SAMPLING_RES = %u;
f.write('''const float AP_Declination::SAMPLING_RES = %u;
const float AP_Declination::SAMPLING_MIN_LAT = %u;
const float AP_Declination::SAMPLING_MAX_LAT = %u;
const float AP_Declination::SAMPLING_MIN_LON = %u;
const float AP_Declination::SAMPLING_MAX_LON = %u;
''' % (SAMPLING_RES,
SAMPLING_MIN_LAT,
SAMPLING_MAX_LAT,
SAMPLING_MIN_LON,
SAMPLING_MAX_LON))
SAMPLING_MIN_LAT,
SAMPLING_MAX_LAT,
SAMPLING_MIN_LON,
SAMPLING_MAX_LON))
def write_table(name, table):
'''write one table'''
tfile.write("const float AP_Declination::%s[%u][%u] = {\n" %
(name, NUM_LAT, NUM_LON))
for i in range(NUM_LAT):
tfile.write(" {")
for j in range(NUM_LON):
tfile.write("%.5f" % table[i][j])
if j != NUM_LON-1:
tfile.write(",")
tfile.write("}")
if i != NUM_LAT-1:
tfile.write(",")
tfile.write("\n")
tfile.write("};\n\n")
write_table(f,'declination_table', declination_table)
write_table(f,'inclination_table', inclination_table)
write_table(f,'intensity_table', intensity_table)
write_table('declination_table', declination_table)
write_table('inclination_table', inclination_table)
write_table('intensity_table', intensity_table)
tfile.close()