/usr/lib/python2.7/dist-packages/fiona/crs.py is in python-fiona 1.7.1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 | """Coordinate reference systems and functions
PROJ.4 is the law of this land: http://proj.osgeo.org/. But whereas PROJ.4
coordinate reference systems are described by strings of parameters such as
+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs
here we use mappings:
{'proj': 'longlat', 'ellps': 'WGS84', 'datum': 'WGS84', 'no_defs': True}
"""
from six import string_types
def to_string(crs):
"""Turn a parameter mapping into a more conventional PROJ.4 string.
Mapping keys are tested against the ``all_proj_keys`` list. Values of
``True`` are omitted, leaving the key bare: {'no_defs': True} -> "+no_defs"
and items where the value is otherwise not a str, int, or float are
omitted.
"""
items = []
for k, v in sorted(filter(
lambda x: x[0] in all_proj_keys and x[1] is not False and (
isinstance(x[1], (bool, int, float)) or
isinstance(x[1], string_types)),
crs.items())):
items.append(
"+" + "=".join(
map(str, filter(
lambda y: (y or y == 0) and y is not True, (k, v)))))
return " ".join(items)
def from_string(prjs):
"""Turn a PROJ.4 string into a mapping of parameters.
Bare parameters like "+no_defs" are given a value of ``True``. All keys
are checked against the ``all_proj_keys`` list.
"""
parts = [o.lstrip('+') for o in prjs.strip().split()]
def parse(v):
try:
return int(v)
except ValueError:
pass
try:
return float(v)
except ValueError:
return v
items = map(
lambda kv: len(kv) == 2 and (kv[0], parse(kv[1])) or (kv[0], True),
(p.split('=') for p in parts))
return dict((k, v) for k, v in items if k in all_proj_keys)
def from_epsg(code):
"""Given an integer code, returns an EPSG-like mapping.
Note: the input code is not validated against an EPSG database.
"""
if int(code) <= 0:
raise ValueError("EPSG codes are positive integers")
return {'init': "epsg:%s" % code, 'no_defs': True}
# Below is the big list of PROJ4 parameters from
# http://trac.osgeo.org/proj/wiki/GenParms.
# It is parsed into a list of paramter keys ``all_proj_keys``.
_param_data = """
+a Semimajor radius of the ellipsoid axis
+alpha ? Used with Oblique Mercator and possibly a few others
+axis Axis orientation (new in 4.8.0)
+b Semiminor radius of the ellipsoid axis
+datum Datum name (see `proj -ld`)
+ellps Ellipsoid name (see `proj -le`)
+init Initialize from a named CRS
+k Scaling factor (old name)
+k_0 Scaling factor (new name)
+lat_0 Latitude of origin
+lat_1 Latitude of first standard parallel
+lat_2 Latitude of second standard parallel
+lat_ts Latitude of true scale
+lon_0 Central meridian
+lonc ? Longitude used with Oblique Mercator and possibly a few others
+lon_wrap Center longitude to use for wrapping (see below)
+nadgrids Filename of NTv2 grid file to use for datum transforms (see below)
+no_defs Don't use the /usr/share/proj/proj_def.dat defaults file
+over Allow longitude output outside -180 to 180 range, disables wrapping (see below)
+pm Alternate prime meridian (typically a city name, see below)
+proj Projection name (see `proj -l`)
+south Denotes southern hemisphere UTM zone
+to_meter Multiplier to convert map units to 1.0m
+towgs84 3 or 7 term datum transform parameters (see below)
+units meters, US survey feet, etc.
+vto_meter vertical conversion to meters.
+vunits vertical units.
+x_0 False easting
+y_0 False northing
+zone UTM zone
+a Semimajor radius of the ellipsoid axis
+alpha ? Used with Oblique Mercator and possibly a few others
+azi
+b Semiminor radius of the ellipsoid axis
+belgium
+beta
+czech
+e Eccentricity of the ellipsoid = sqrt(1 - b^2/a^2) = sqrt( f*(2-f) )
+ellps Ellipsoid name (see `proj -le`)
+es Eccentricity of the ellipsoid squared
+f Flattening of the ellipsoid (often presented as an inverse, e.g. 1/298)
+gamma
+geoc
+guam
+h
+k Scaling factor (old name)
+K
+k_0 Scaling factor (new name)
+lat_0 Latitude of origin
+lat_1 Latitude of first standard parallel
+lat_2 Latitude of second standard parallel
+lat_b
+lat_t
+lat_ts Latitude of true scale
+lon_0 Central meridian
+lon_1
+lon_2
+lonc ? Longitude used with Oblique Mercator and possibly a few others
+lsat
+m
+M
+n
+no_cut
+no_off
+no_rot
+ns
+o_alpha
+o_lat_1
+o_lat_2
+o_lat_c
+o_lat_p
+o_lon_1
+o_lon_2
+o_lon_c
+o_lon_p
+o_proj
+over
+p
+path
+proj Projection name (see `proj -l`)
+q
+R
+R_a
+R_A Compute radius such that the area of the sphere is the same as the area of the ellipsoid
+rf Reciprocal of the ellipsoid flattening term (e.g. 298)
+R_g
+R_h
+R_lat_a
+R_lat_g
+rot
+R_V
+s
+south Denotes southern hemisphere UTM zone
+sym
+t
+theta
+tilt
+to_meter Multiplier to convert map units to 1.0m
+units meters, US survey feet, etc.
+vopt
+W
+westo
+x_0 False easting
+y_0 False northing
+zone UTM zone
+wktext Marker
"""
_lines = filter(lambda x: len(x) > 1, _param_data.split("\n"))
all_proj_keys = list(
set(line.split()[0].lstrip("+").strip() for line in _lines)) + ['no_mayo']
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