"""
Pyrex wrapper to provide python interfaces to
PROJ.4 (http://proj.maptools.org) functions.
Performs cartographic transformations (converts from longitude,latitude
to native map projection x,y coordinates and vice versa, or from
one map projection coordinate system directly to another).
Example usage:
>>> from pyproj import Proj
>>> p = Proj(proj='utm',zone=10)
>>> x,y = p(-120.108, 34.36116666)
>>> print x,y
>>> print p(x,y,inverse=True)
765975.641091 3805993.13406
(-120.10799999995851, 34.3611.79972767)
Input coordinates can be given as python arrays, lists/tuples, scalars
or Numeric/numarray/numpy arrays. Optimized for objects that support
the Python buffer protocol (regular python, Numeric, numarray and
numpy arrays).
Download http://www.cdc.noaa.gov/people/jeffrey.s.whitaker/python/pyproj-1.7.2.tar.gz
See the docstrings for pyproj.Proj and pyproj.transform for more documentation.
Examples scripts are in 'test' subdirectory of source distribution.
Contact: Jeffrey Whitaker <jeffrey.s.whitaker@noaa.gov
copyright (c) 2006 by Jeffrey Whitaker.
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both the copyright notice and this permission notice appear in
supporting documentation.
THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
"""
# Make changes to this file, not the c-wrappers that Pyrex generates.
import math, array, types
cdef double _rad2dg, _dg2rad
cdef int _doublesize
_dg2rad = math.radians(1.)
_rad2dg = math.degrees(1.)
_doublesize = sizeof(double)
__version__ = "1.7.2"
_seqtype = [types.ListType,types.TupleType]
cdef extern from "proj_api.h":
ctypedef double *projPJ
ctypedef struct projUV:
double u
double v
projPJ pj_init_plus(char *)
projUV pj_fwd(projUV, projPJ)
projUV pj_inv(projUV, projPJ)
int pj_transform(projPJ src, projPJ dst, long point_count, int point_offset,
double *x, double *y, double *z)
int pj_is_latlong(projPJ)
int pj_is_geocent(projPJ)
char *pj_strerrno(int)
void pj_free(projPJ)
cdef enum:
PJ_VERSION
cdef extern from "Python.h":
int PyObject_AsWriteBuffer(object, void **rbuf, int *len)
char *PyString_AsString(object)
cdef class Proj:
"""
performs cartographic transformations (converts from longitude,latitude
to native map projection x,y coordinates and vice versa) using proj
(http://proj.maptools.org/)
A Proj class instance is initialized with
proj map projection control parameter key/value pairs.
The key/value pairs can either be passed in a dictionary,
or as keyword arguments.
See http://www.remotesensing.org/geotiff/proj_list for
examples of key/value pairs defining different map projections.
Calling a Proj class instance with the arguments lon, lat will
convert lon/lat (in degrees) to x/y native map projection
coordinates (in meters). If optional keyword 'inverse' is
True (default is False), the inverse transformation from x/y
to lon/lat is performed. If optional keyword 'radians' is True
(default is False) lon/lat are interpreted as radians instead
of degrees. Works with numarray/Numeric/numpy/regular python
array objects, lists, tuples or scalars (fastest for arrays). lon and
lat must be of same type (array, list/tuple or scalar) and have the
same length (if array, list or tuple).
"""
cdef projPJ projpj
cdef public object projparams
cdef public object proj_version
cdef char *pjinitstring
def __new__(self, projparams=None, **kwargs):
"""
initialize a Proj class instance.
Proj4 projection control parameters must either be
given in a dictionary 'projparams' or as keyword arguments.
See the proj documentation (http://proj.maptools.org) for more
information about specifying projection parameters.
"""
# if projparams is None, use kwargs.
if projparams is None:
if len(kwargs) == 0:
raise RuntimeError, 'no projection control parameters specified'
else:
projparams = kwargs
# set units to meters.
if not projparams.has_key('units'):
projparams['units']='m'
elif projparams['units'] != 'm':
print 'resetting units to meters ...'
projparams['units']='m'
# setup proj initialization string.
pjargs = []
for key,value in projparams.iteritems():
pjargs.append('+'+key+"="+str(value)+' ')
self.projparams = projparams
self.pjinitstring = PyString_AsString(''.join(pjargs))
# initialize projection
self.projpj = pj_init_plus(self.pjinitstring)
if self.projpj == NULL:
msg = """projection initialization failed.
try running proj %s
in a terminal to get a more informative error message""" % self.pjinitstring
raise RuntimeError(msg)
self.proj_version = PJ_VERSION/100.
def __dealloc__(self):
"""destroy projection definition"""
pj_free(self.projpj)
def __reduce__(self):
"""special method that allows pyproj.Proj instance to be pickled"""
return (self.__class__,(self.projparams,))
def _fwd(self, object lons, object lats, radians=False):
"""
forward transformation - lons,lats to x,y.
if radians=True, lons/lats are radians instead of degrees.
"""
cdef projUV projxyout, projlonlatin
cdef int ndim, i, buflenx, bufleny
cdef double u, v
cdef double *lonsdata, *latsdata
cdef void *londata, *latdata
# if buffer api is supported, get pointer to data buffers.
if PyObject_AsWriteBuffer(lons, &londata, &buflenx) <> 0:
raise RuntimeError
if PyObject_AsWriteBuffer(lats, &latdata, &bufleny) <> 0:
raise RuntimeError
# process data in buffer
if buflenx != bufleny:
raise RuntimeError("Buffer lengths not the same")
ndim = buflenx/_doublesize
lonsdata = <double *>londata
latsdata = <double *>latdata
if radians:
for i from 0 <= i < ndim:
projlonlatin.u = lonsdata[i]
projlonlatin.v = latsdata[i]
projxyout = pj_fwd(projlonlatin,self.projpj)
lonsdata[i] = projxyout.u
latsdata[i] = projxyout.v
else:
for i from 0 <= i < ndim:
projlonlatin.u = _dg2rad*lonsdata[i]
projlonlatin.v = _dg2rad*latsdata[i]
projxyout = pj_fwd(projlonlatin,self.projpj)
lonsdata[i] = projxyout.u
latsdata[i] = projxyout.v
return lons, lats
def _inv(self, object x, object y, radians=False):
"""
inverse transformation - x,y to lons,lats.
if radians=True, lons/lats are radians instead of degrees.
"""
cdef projUV projxyin, projlonlatout
cdef int ndim, i, buflenx, bufleny
cdef double u, v
cdef void *xdata, *ydata
cdef double *xdatab, *ydatab
# if buffer api is supported, get pointer to data buffers.
if PyObject_AsWriteBuffer(x, &xdata, &buflenx) <> 0:
raise RuntimeError
if PyObject_AsWriteBuffer(y, &ydata, &bufleny) <> 0:
raise RuntimeError
# process data in buffer
# (for Numeric/numarray/numpy/regular python arrays).
if buflenx != bufleny:
raise RuntimeError("Buffer lengths not the same")
ndim = buflenx/_doublesize
xdatab = <double *>xdata
ydatab = <double *>ydata
if radians:
for i from 0 <= i < ndim:
projxyin.u = xdatab[i]
projxyin.v = ydatab[i]
projlonlatout = pj_inv(projxyin,self.projpj)
xdatab[i] = projlonlatout.u
ydatab[i] = projlonlatout.v
else:
for i from 0 <= i < ndim:
projxyin.u = xdatab[i]
projxyin.v = ydatab[i]
projlonlatout = pj_inv(projxyin,self.projpj)
xdatab[i] = _rad2dg*projlonlatout.u
ydatab[i] = _rad2dg*projlonlatout.v
return x,y
def __call__(self,lon,lat,inverse=False,radians=False):
"""
Calling a Proj class instance with the arguments lon, lat will
convert lon/lat (in degrees) to x/y native map projection
coordinates (in meters). If optional keyword 'inverse' is
True (default is False), the inverse transformation from x/y
to lon/lat is performed. If optional keyword 'radians' is
True (default is False) the units of lon/lat are radians instead
of degrees.
Inputs should be doubles (they will be cast to doubles
if they are not, causing a slight performance hit).
Works with Numeric/numarray/numpy/regular python arrays,
python lists/tuples or scalars (fastest for arrays).
"""
# if lon,lat support BufferAPI, must make sure they contain doubles.
isfloat = False; islist = False
# first, if it's a numpy array scalar convert to float
# (array scalars don't support buffer API)
if hasattr(lon,'shape') and lon.shape == (): lon = float(lon)
if hasattr(lat,'shape') and lat.shape == (): lat = float(lat)
try:
# typecast Numeric/numarray arrays to double.
# (this makes a copy)
lon.typecode()
lat.typecode()
inx = lon.astype('d')
iny = lat.astype('d')
except:
try: # perhaps they are numpy arrays?
lon.dtype.char
lat.dtype.char
inx = lon.astype('d')
iny = lat.astype('d')
except:
# perhaps they are regular python arrays?
try:
lon.typecode
lat.typecode
inx = array.array('d',lon)
iny = array.array('d',lat)
except:
# none of the above
# try to convert to python array
# a list or tuple.
if type(lon) in _seqtype and type(lat) in _seqtype:
inx = array.array('d',lon)
iny = array.array('d',lat)
islist = True
# a float.
else:
try:
lon = float(lon)
lat = float(lat)
inx = array.array('d',(lon,))
iny = array.array('d',(lat,))
isfloat = True
except:
raise TypeError, 'lon and latmust be arrays, lists/tuples or scalars (and they must all be of the same type)'
# call proj4 functions.
if inverse:
outx, outy = self._inv(inx, iny, radians=radians)
else:
outx, outy = self._fwd(inx, iny, radians=radians)
# all done.
# if inputs were lists, tuples or floats, convert back.
if isfloat:
return outx[0],outy[0]
elif islist:
# note: if input was a tuple, output will be a list.
return outx.tolist(),outy.tolist()
else:
return outx,outy
def is_latlong(self):
"""returns True if projection in geographic (lon/lat) coordinates"""
cdef int i
i = pj_is_latlong(self.projpj)
if i:
return True
else:
return False
def is_geocent(self):
"""returns True if projection in geocentric (x/y) coordinates"""
cdef int i
i = pj_is_geocent(self.projpj)
if i:
return True
else:
return False
def transform(Proj p1, Proj p2, x, y, z=None, radians=False):
"""
x2, y2, z2 = transform(p1, p2, x1, y1, z1, radians=False)
Transform points between two coordinate systems defined
by the Proj instances p1 and p2.
The points x1,y1,z1 in the coordinate system defined by p1
are transformed to x2,y2,z2 in the coordinate system defined by p2.
z1 is optional, if it is not set it is assumed to be zero (and
only x2 and y2 are returned).
In addition to converting between cartographic and geographic
projection coordinates, this function can take care of datum shifts
(which cannot be done using the __call__ method of the Proj instances).
It also allows for one of the coordinate systems to be geographic
(proj = 'latlong').
If optional keyword 'radians' is True (default is False) and
p1 is defined in geographic coordinate (pj.is_latlong() is True),
x1,y1 is interpreted as radians instead of the default degrees.
Similarly, if p2 is defined in geographic coordinates
and radians=True, x2, y2 are returned in radians instead of degrees.
if p1.is_latlong() and p2.is_latlong() both are False, the
radians keyword has no effect.
x,y and z can be Numeric/numarray/numpy or regular python arrays,
python lists/tuples or scalars. Arrays are fastest. x,y and z must be
all of the same type (array, list/tuple or scalar), and have the
same length (if arrays, lists or tuples).
For projections in geocentric coordinates, values of
x and y are given in meters. z is always meters.
"""
# make sure x,y,z support Buffer API and contain doubles.
isfloat = False; islist = False
# first, if it's a numpy array scalar convert to float
# (array scalars don't support buffer API)
if hasattr(x,'shape') and x.shape == (): x = float(x)
if hasattr(y,'shape') and y.shape == (): y = float(y)
if hasattr(z,'shape') and z.shape == (): z = float(z)
try:
# typecast Numeric/numarray arrays to double.
# (this makes a copy)
x.typecode()
y.typecode()
if z is not None: z.typecode()
inx = x.astype('d')
iny = y.astype('d')
if z is not None:
inz = z.astype('d')
except:
try: # perhaps they are numpy arrays?
x.dtype.char
y.dtype.char
if z is not None: z.dtype.char
inx = x.astype('d')
iny = y.astype('d')
if z is not None:
inz = z.astype('d')
except:
# perhaps they are regular python arrays?
try:
x.typecode
y.typecode
if z is not None: z.typecode
inx = array.array('d',x)
iny = array.array('d',y)
if z is not None:
inz = array.array('d',z)
except:
# try to convert to python array
# a list or tuple?
if type(x) in _seqtype and type(y) in _seqtype and (type(z) is None or type(z) in _seqtype):
inx = array.array('d',x)
iny = array.array('d',y)
if z is not None:
inz = array.array('d',z)
islist = True
# a scalar?
else:
try:
x = float(x)
y = float(y)
if z is not None: z = float(z)
inx = array.array('d',(x,))
iny = array.array('d',(y,))
if z is not None: inz = array.array('d',(z,))
isfloat = True
except:
raise TypeError, 'x, y and z must be arrays, lists/tuples or scalars (and they must all be of the same type)'
ierr = _transform(p1,p2,inx,iny,inz,radians)
if ierr != 0:
raise RuntimeError, pj_strerrno(ierr)
# if inputs were lists, tuples or floats, convert back.
if inz is not None:
if isfloat:
return inx[0],iny[0],inz[0]
elif islist:
# note: if input was a tuple, output will be a list.
return inx.tolist(),iny.tolist(),inz.tolist()
else:
return inx,iny,inz
else:
if isfloat:
return inx[0],iny[0]
elif islist:
# note: if input was a tuple, output will be a list.
return inx.tolist(),iny.tolist()
else:
return inx,iny
cdef _transform(Proj p1, Proj p2, inx, iny, inz, radians):
"""private function to call pj_transform"""
cdef void *xdata, *ydata, *zdata
cdef double *xx, *yy, *zz
cdef int buflenx, bufleny, buflenz, npts, i
if PyObject_AsWriteBuffer(inx, &xdata, &buflenx) <> 0:
raise RuntimeError
if PyObject_AsWriteBuffer(iny, &ydata, &bufleny) <> 0:
raise RuntimeError
if inz is not None:
if PyObject_AsWriteBuffer(inz, &zdata, &buflenz) <> 0:
raise RuntimeError
else:
buflenz = bufleny
if not (buflenx == bufleny == buflenz):
raise RuntimeError,'x,y and z must be same size'
xx = <double *>xdata
yy = <double *>ydata
if inz is not None:
zz = <double *>zdata
npts = buflenx/8
if not radians and p1.is_latlong():
for i from 0 <= i < npts:
xx[i] = xx[i]*_dg2rad
yy[i] = yy[i]*_dg2rad
if inz is not None:
ierr = pj_transform(p1.projpj, p2.projpj, npts, 0, xx, yy, zz)
else:
ierr = pj_transform(p1.projpj, p2.projpj, npts, 0, xx, yy, NULL)
if not radians and p2.is_latlong():
for i from 0 <= i < npts:
xx[i] = xx[i]*_rad2dg
yy[i] = yy[i]*_rad2dg
return ierr
