/
maidenhead.py
193 lines (173 loc) · 5.23 KB
/
maidenhead.py
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"""
/***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
"""
def maidenGridCenter(maiden):
"""
maiden is a string the is even and between 2 to 8 characters
It returns the center point of a maiden grid and throws an exception
on error
"""
if not isinstance(maiden, str):
raise TypeError('Maidenhead locator must be a string')
maiden = maiden.strip().upper()
N = len(maiden)
if not 8 >= N >= 2 and N % 2 == 0:
raise ValueError('Maidenhead locator requires 2-8 characters, even number of characters')
Oa = ord('A')
lon = -180.
lat = -90.
# %% first pair
isValid(maiden[0], 0)
isValid(maiden[1], 0)
lon += (ord(maiden[0])-Oa)*20
lat += (ord(maiden[1])-Oa)*10
if N == 2:
lon += 10
lat += 5
# %% second pair
if N >= 4:
isValid(maiden[2], 1)
isValid(maiden[3], 1)
lon += int(maiden[2])*2
lat += int(maiden[3])*1
if N == 4:
lon += 1
lat += 0.5
# %%
if N >= 6:
isValid(maiden[4], 2)
isValid(maiden[5], 2)
lon += (ord(maiden[4])-Oa) * 5./60
lat += (ord(maiden[5])-Oa) * 2.5/60
if N == 6:
lon += 5./120
lat += 2.5/120
# %%
if N == 8:
lon += int(maiden[6]) * 5./600
lat += int(maiden[7]) * 2.5/600
lon += 5./1200
lat += 2.5/1200
return lat, lon
def maidenGrid(maiden):
"""
maiden is a string the is even and between 2 to 8 characters
It returns the center point of a maiden grid and throws an exception
on error
"""
if not isinstance(maiden, str):
raise TypeError('Maidenhead locator must be a string')
maiden = maiden.strip().upper()
N = len(maiden)
if not 8 >= N >= 2 and N % 2 == 0:
raise ValueError('Maidenhead locator requires 2-8 characters, even number of characters')
Oa = ord('A')
lon = -180.
lat = -90.
# %% first pair
isValid(maiden[0], 0)
isValid(maiden[1], 0)
lon += (ord(maiden[0])-Oa)*20
lat += (ord(maiden[1])-Oa)*10
if N == 2:
lon1 = lon
lat1 = lat
lon2 = lon + 20
lat2 = lat + 10
lon += 10
lat += 5
# %% second pair
if N >= 4:
isValid(maiden[2], 1)
isValid(maiden[3], 1)
lon += int(maiden[2])*2
lat += int(maiden[3])*1
if N == 4:
lon1 = lon
lat1 = lat
lon2 = lon + 2
lat2 = lat + 1
lon += 1
lat += 0.5
# %%
if N >= 6:
isValid(maiden[4], 2)
isValid(maiden[5], 2)
lon += (ord(maiden[4])-Oa) * 5./60
lat += (ord(maiden[5])-Oa) * 2.5/60
if N == 6:
lon1 = lon
lat1 = lat
lon2 = lon + 5./60
lat2 = lat + 2.5/60
lon += 5./120
lat += 2.5/120
# %%
if N == 8:
lon += int(maiden[6]) * 5./600
lat += int(maiden[7]) * 2.5/600
lon1 = lon
lat1 = lat
lon2 = lon + 5./600
lat2 = lat + 2.5/600
lon += 5./1200
lat += 2.5/1200
return lat, lon, lat1, lon1, lat2, lon2
def isValid(c, level):
if level == 0:
if not 'R' >= c >= 'A':
raise ValueError('Invalid maidenhead encoding')
if level == 1 or level == 3:
if not '9' >= c >= '0':
raise ValueError('Invalid maidenhead encoding')
if level == 2:
if not 'X' >= c >= 'A':
raise ValueError('Invalid maidenhead encoding')
return(True)
def toMaiden(lat, lon=None,precision = 3):
"""
Returns a maidenhead string for latitude, longitude at specified level.
Parameters
----------
lat : float or tuple of float
latitude or tuple of latitude, longitude
lon : float, optional
longitude (if not given tuple)
precision : int, optional
level of precision (length of maidenhead grid string output)
Returns
-------
maiden : str
Maidenhead grid string of specified precision
"""
if lon < -180.0 or lon > 180.0 or lat < -90.0 or lat > 90.0:
raise ValueError('Maidenhead: invalid latitude and longitude')
A = ord('A')
a = divmod(lon+180, 20)
b = divmod(lat+90, 10)
maiden = chr(A+int(a[0])) + chr(A+int(b[0]))
lon = a[1] / 2.
lat = b[1]
i = 1
while i < precision:
i += 1
a = divmod(lon, 1)
b = divmod(lat, 1)
if not (i % 2):
maiden += str(int(a[0])) + str(int(b[0]))
lon = 24 * a[1]
lat = 24 * b[1]
else:
maiden += chr(A+int(a[0])) + chr(A+int(b[0]))
lon = 10 * a[1]
lat = 10 * b[1]
if len(maiden) >= 6:
maiden = maiden[:4] + maiden[4:6].lower() + maiden[6:]
return maiden