New subdivisioning of package, and added red warnings during testing

pycrs/elements/__init__.py

@@ -0,0 +1,6 @@
+from . import datums
+from . import ellipsoids
+from . import projections
+from . import units
+from . import directions
+from . import parameters

pycrs/elements/datums.py

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+
+
+def find(datumname, crstype, strict=False):
+    if not strict:
+        datumname = datumname.lower()
+    for itemname,item in globals().items():
+        if itemname.startswith("_"):
+            continue
+        try:
+            if hasattr(item, crstype):
+                itemname = getattr(item, crstype)
+                if not strict:
+                    itemname = itemname.lower()
+                if datumname == itemname:
+                    return item
+        except:
+            pass
+    else:
+        return None
+
+    
+
+
+class WGS84:
+    proj4 = "WGS84"
+    ogc_wkt = "WGS_1984"
+    esri_wkt = "D_WGS_1984"
+
+    ellipsdef = "" # ellipsoids.WGS84()
+    to_wgs84 = None
+
+class WGS72_BE:
+    proj4 = "" # no datum name, just ellips + towgs84 params...
+    ogc_wkt = "WGS_1972_Transit_Broadcast_Ephemeris"
+    esri_wkt = "D_WGS_1972_BE"
+
+    ellipsdef = "" # ellipsoids.WGS72()
+    to_wgs84 = 0,0,1.9,0,0,0.814,-0.38
+
+class NAD83:
+    proj4 = "NAD83" # no datum name, just ellips + towgs84 params...
+    ogc_wkt = "North_American_Datum_1983"
+    esri_wkt = "D_North_American_1983"
+
+    ellipsdef = "" # ellipsoids.WGS72()
+    to_wgs84 = None
+
+class NAD27:
+    proj4 = "NAD27"
+    ogc_wkt = "D_North_American_1927"
+    esri_wkt = "D_North_American_1927"
+    
+    ellipsdef = "" # ellipsoids...
+    to_wgs84 = None
+
+class SphereArcInfo:
+    proj4 = "" # no name
+    ogc_wkt = "D_Sphere_ARC_INFO" # confirmed but odd that uses D_
+    esri_wkt = "D_Sphere_ARC_INFO"
+
+    semimaj_ax = 6370997.0
+    inv_flat = 0.0
+
+class Unknown:
+    proj4 = "unknown" # no datum name, just ellips + towgs84 params...
+    ogc_wkt = "Unknown"
+    esri_wkt = "Unknown"
+
+    ellipsdef = "" # ellipsoids.WGS72()
+    to_wgs84 = None,None

pycrs/elements/directions.py

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+
+class North:
+    proj4 = "n"
+    ogc_wkt = "NORTH"
+    esri_wkt = "NORTH"
+
+class East:
+    proj4 = "e"
+    ogc_wkt = "EAST"
+    esri_wkt = "EAST"
+
+class South:
+    proj4 = "s"
+    ogc_wkt = "SOUTH"
+    esri_wkt = "SOUTH"
+
+class West:
+    proj4 = "w"
+    ogc_wkt = "WEST"
+    esri_wkt = "WEST"
+
+class Up:
+    proj4 = "u"
+    ogc_wkt = "UP"
+    esri_wkt = "UP"
+
+class Down:
+    proj4 = "d"
+    ogc_wkt = "DOWN"
+    esri_wkt = "DOWN"
+    

pycrs/elements/ellipsoids.py

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+
+
+def find(ellipsname, crstype, strict=False):
+    if not strict:
+        ellipsname = ellipsname.lower()
+    for itemname,item in globals().items():
+        if itemname.startswith("_"):
+            continue
+        try:
+            if hasattr(item, crstype):
+                itemname = getattr(item, crstype)
+                if not strict:
+                    itemname = itemname.lower()
+                if ellipsname == itemname:
+                    return item
+        except:
+            pass
+    else:
+        return None
+
+
+
+
+
+class WGS84:
+    proj4 = "WGS84"
+    ogc_wkt = "WGS_1984"
+    esri_wkt = "WGS_1984"
+    
+    semimaj_ax = 6378137
+    inv_flat = 298.257223563
+    
+
+class WGS72:
+    proj4 = "WGS72"
+    ogc_wkt = "WGS 72"
+    esri_wkt = "WGS_1972"
+
+    semimaj_ax = 6378135
+    inv_flat = 298.26
+
+class International:
+    proj4 = "intl"
+    ogc_wkt = "International_1924"
+    esri_wkt = "International_1924"
+
+    semimaj_ax = 6378388.0
+    inv_flat = 297.0
+
+class GRS80:
+    proj4 = "GRS80"
+    ogc_wkt = "GRS_1980"
+    esri_wkt = "GRS_1980"
+
+    semimaj_ax = 6378137.0
+    inv_flat = 298.257222101
+
+class Clarke1866:
+    proj4 = "clrk66"
+    ogc_wkt = "Clarke_1866"
+    esri_wkt = "Clarke_1866"
+
+    semimaj_ax = 6378206.4
+    inv_flat = 294.9786982
+
+class Airy1830:
+    proj4 = "airy"
+    ogc_wkt = "Airy 1830"
+    esri_wkt = "Airy_1830"
+
+    semimaj_ax = 6377563.396
+    inv_flat = 299.3249646
+
+class SphereArcInfo:
+    proj4 = "" # no name
+    ogc_wkt = "Sphere_ARC_INFO"
+    esri_wkt = "Sphere_ARC_INFO"
+
+    semimaj_ax = 6370997.0
+    inv_flat = 0.0
+
+
+
+
+
+
+
+
+
+    

pycrs/elements/parameters.py

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+
+#################
+# CRS CLASSES
+#################
+
+# first classes for each crs element, from the proj4 common paramter listing
+# https://trac.osgeo.org/proj/wiki/GenParms
+
+# note also that in wkt the names of "PROJECTION", "DATUM", and "SPHEROID"
+# matter and seem to be interpreted and computed upon, ie they carry meaning
+# that is commonly understood by programs, so is not explicit in the crs specification.
+
+# the paramters below simply modify certain aspects of the proj/datum/spheroids
+
+# note that the names in wkt of "PROJCS" and "GEOGCS" seem to be purely
+# for identifying and branding and can be changed at will.
+# they do however act as shortcuts, so that proj4 can use +init=... to load
+# everything automatically
+
+# some of these names imply certain combinations of datum and spheroid and paramters.
+# so in proj4 one simply needs to give that name, but in wkt one needs to spell it all out.
+
+# +unit and +to_metre are what makes up 'UNIT["Meter",1.0]'
+
+from . import datums
+from . import directions
+
+################
+
+def find(paramname, crstype, strict=False):
+    if not strict:
+        paramname = paramname.lower()
+    for itemname,item in globals().items():
+        if itemname.startswith("_"):
+            continue
+        try:
+            if hasattr(item, crstype):
+                itemname = getattr(item, crstype)
+                if not strict:
+                    itemname = itemname.lower()
+                if paramname == itemname:
+                    return item
+        except:
+            pass
+    else:
+        return None
+    
+
+# NOT CURRENTLY USED, BUT SHOULD BE
+# FOR NOW ONLY SET AS PURE VALUES INSIDE ELLIPSOID...
+
+####+a         Semimajor radius of the ellipsoid axis
+##class SemiMajorRadius:
+##    proj4 = "+a"    
+##    def __init__(self, value):
+##        pass
+##
+####+b         Semiminor radius of the ellipsoid axis
+##class SemiMinorRadius:
+##    proj4 = "+b"
+##    def __init__(self, value):
+##        pass
+    
+
+
+#################
+
+##+alpha     ? Used with Oblique Mercator and possibly a few others
+class Azimuth:
+    proj4 = "+alpha"
+    esri_wkt = "azimuth"
+    ogc_wkt = "azimuth"
+    geotiff = "AzimuthAngle"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+alpha=%s" % self.value
+
+    def to_ogc_wkt(self):
+        return 'PARAMETER["Azimuth",%s]' % self.value
+
+    def to_esri_wkt(self):
+        return 'PARAMETER["Azimuth",%s]' % self.value
+    
+##+datum     Datum name (see `proj -ld`)
+class Datum:
+    proj4 = "+datum"
+    ogc_wkt = "DATUM"
+    esri_wkt = "DATUM"
+    
+    def __init__(self, name, ellipsoid, datumshift=None):
+        """
+        Arguments:
+
+        - **name**: Specific datum name instance.
+        - **ellipsoid**: Ellipsoid parameter instance. 
+        """
+        self.name = name
+        self.ellips = ellipsoid
+        self.datumshift = datumshift
+
+    def to_proj4(self):
+        if self.datumshift:
+            return "%s %s" % (self.ellips.to_proj4(), self.datumshift.to_proj4())
+        elif isinstance(self.name, datums.Unknown):
+            return "%s" % self.ellips.to_proj4()
+        else:
+            return "+datum=%s %s" % (self.name.proj4, self.ellips.to_proj4())
+
+    def to_ogc_wkt(self):
+        if self.datumshift:
+            return 'DATUM["%s", %s, %s]' % (self.name.ogc_wkt, self.ellips.to_ogc_wkt(), self.datumshift.to_ogc_wkt())
+        else:
+            return 'DATUM["%s", %s]' % (self.name.ogc_wkt, self.ellips.to_ogc_wkt())
+
+    def to_esri_wkt(self):
+        if self.datumshift:
+            return 'DATUM["%s", %s, %s]' % (self.name.esri_wkt, self.ellips.to_esri_wkt(), self.datumshift.to_esri_wkt())
+        else:
+            return 'DATUM["%s", %s]' % (self.name.esri_wkt, self.ellips.to_esri_wkt())
+
+    def to_geotiff(self):
+        pass
+        #return "GeogGeodeticDatum" 
+    
+##+ellps     Ellipsoid name (see `proj -le`)
+class Ellipsoid:
+    proj4 = "+ellps"
+    ogc_wkt = "SPHEROID"
+    esri_wkt = "SPHEROID"
+
+    def __init__(self, name, semimaj_ax=None, inv_flat=None):
+        """
+        Arguments:
+
+        - **name**: Specific ellipsoid name instance. 
+        """
+        self.name = name
+        
+        # get default values if not specified
+        if semimaj_ax == None:
+            semimaj_ax = self.name.semimaj_ax
+        if inv_flat == None:
+            inv_flat = self.name.inv_flat
+                
+        self.semimaj_ax = semimaj_ax
+        self.inv_flat = inv_flat
+
+    def to_proj4(self):
+        return "+ellps=%s +a=%s +f=%s" % (self.name.proj4, self.semimaj_ax, self.inv_flat)
+
+    def to_ogc_wkt(self):
+        return 'SPHEROID["%s", %s, %s]' % (self.name.ogc_wkt, self.semimaj_ax, self.inv_flat)
+    
+    def to_esri_wkt(self):
+        return 'SPHEROID["%s", %s, %s]' % (self.name.esri_wkt, self.semimaj_ax, self.inv_flat)
+
+    def to_geotiff(self):
+        pass
+        #return "GeogEllipsoid"
+
+#GEOGCS
+class GeogCS:
+    ogc_wkt = "GEOGCS"
+    esri_wkt = "GEOGCS"
+
+    def __init__(self, name, datum, prime_mer, angunit, twin_ax=None):
+        """
+        Arguments:
+
+        - **name**: Arbitrary name. 
+        """
+        self.name = name
+        self.datum = datum
+        self.prime_mer = prime_mer
+        self.angunit = angunit
+        if twin_ax == None:
+            # default axes
+            twin_ax = directions.East(), directions.North()
+        self.twin_ax = twin_ax
+
+    def to_proj4(self):
+        # dont parse axis to proj4, because in proj4, axis only applies to the cs, ie the projcs (not the geogcs, where wkt can specify with axis)
+        return "%s %s %s" % (self.datum.to_proj4(), self.prime_mer.to_proj4(), self.angunit.to_proj4() ) 
+
+    def to_ogc_wkt(self):
+        return 'GEOGCS["%s", %s, %s, %s, AXIS["Lon", %s], AXIS["Lat", %s]]' % (self.name, self.datum.to_ogc_wkt(), self.prime_mer.to_ogc_wkt(), self.angunit.to_ogc_wkt(), self.twin_ax[0].ogc_wkt, self.twin_ax[1].ogc_wkt )
+    
+    def to_esri_wkt(self):
+        return 'GEOGCS["%s", %s, %s, %s, AXIS["Lon", %s], AXIS["Lat", %s]]' % (self.name, self.datum.to_esri_wkt(), self.prime_mer.to_esri_wkt(), self.angunit.to_esri_wkt(), self.twin_ax[0].esri_wkt, self.twin_ax[1].esri_wkt )
+
+#PROJCS
+class ProjCS:
+    ogc_wkt = "PROJCS"
+    esri_wkt = "PROJCS"
+    
+    def __init__(self, name, geogcs, proj, params, unit, twin_ax=None):
+        """
+        Arguments:
+
+        - **name**: Arbitrary name. 
+        """
+        self.name = name
+        self.geogcs = geogcs
+        self.proj = proj
+        self.params = params
+        self.unit = unit
+        if twin_ax == None:
+            # default axes
+            twin_ax = directions.East(), directions.North()
+        self.twin_ax = twin_ax
+
+    def to_proj4(self):
+        string = "%s %s " % (self.proj.to_proj4(), self.geogcs.to_proj4())
+        string += " ".join(param.to_proj4() for param in self.params)
+        string += " %s" % self.unit.to_proj4()
+        string += " +axis=" + self.twin_ax[0].proj4 + self.twin_ax[1].proj4 + "u" # up set as default because only proj4 can set it I think...
+        return string
+
+    def to_ogc_wkt(self):
+        string = 'PROJCS["%s", %s, %s, ' % (self.name, self.geogcs.to_ogc_wkt(), self.proj.to_ogc_wkt() )
+        string += ", ".join(param.to_ogc_wkt() for param in self.params)
+        string += ', %s' % self.unit.to_ogc_wkt()
+        string += ', AXIS["X", %s], AXIS["Y", %s]]' % (self.twin_ax[0].ogc_wkt, self.twin_ax[1].ogc_wkt )
+        return string
+    
+    def to_esri_wkt(self):
+        string = 'PROJCS["%s", %s, %s, ' % (self.name, self.geogcs.to_esri_wkt(), self.proj.to_esri_wkt() )
+        string += ", ".join(param.to_esri_wkt() for param in self.params)
+        string += ', %s' % self.unit.to_esri_wkt()
+        string += ', AXIS["X", %s], AXIS["Y", %s]]' % (self.twin_ax[0].esri_wkt, self.twin_ax[1].esri_wkt )
+        return string
+
+##+k         Scaling factor (old name)
+##+k_0       Scaling factor (new name)
+class ScalingFactor:
+    proj4 = "+k"
+    ogc_wkt = "scale_factor"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+k_0=%s" %self.value
+
+    def to_ogc_wkt(self):
+        return 'PARAMETER["scale_factor", %s]' %self.value
+
+    def to_esri_wkt(self):
+        # REALLY??
+        raise Exception("Paramater not supported by ESRI WKT")
+
+    def to_geotiff(self):
+        pass
+        #return "ScaleAtNatOrigin" # or ScaleAtCenter?
+
+##+lat_0     Latitude of origin
+class LatitudeOrigin:
+    proj4 = "+lat_0"
+    ogc_wkt = "latitude_of_origin"
+    esri_wkt = "Latitude_Of_Origin"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+lat_0=%s" %self.value
+
+    def to_ogc_wkt(self):
+        # SAME AS LATITUDE OF CENTER???
+        return 'PARAMETER["latitude_of_origin", %s]' %self.value
+
+    def to_esri_wkt(self):
+        return 'PARAMETER["Latitude_Of_Origin", %s]' %self.value
+
+    def to_geotiff(self):
+        pass
+        #return "ProjCenterLat"
+    
+##+lat_1     Latitude of first standard parallel
+class LatitudeFirstStndParallel:
+    proj4 = "+lat_1"
+    ogc_wkt = "standard_parallel_1"
+    esri_wkt = "Standard_Parallel_1"
+    
+    def __init__(self, value):
+        self.value = value
+        
+    def to_proj4(self):
+        return "+lat_1=%s" %self.value
+
+    def to_ogc_wkt(self):
+        return 'PARAMETER["standard_parallel_1", %s]' %self.value
+
+    def to_esri_wkt(self):
+        return 'PARAMETER["Standard_Parallel_1", %s]' %self.value
+
+    def to_geotiff(self):
+        pass
+        #return "StdParallel1"
+    
+##+lat_2     Latitude of second standard parallel
+class LatitudeSecondStndParallel:
+    proj4 = "+lat_2"
+    ogc_wkt = "standard_parallel_2"
+    esri_wkt = "Standard_Parallel_2"
+    
+    def __init__(self, value):
+        self.value = value
+    
+    def to_proj4(self):
+        return "+lat_2=%s" %self.value
+
+    def to_ogc_wkt(self):
+        return 'PARAMETER["standard_parallel_2", %s]' %self.value
+
+    def to_esri_wkt(self):
+        return 'PARAMETER["Standard_Parallel_2", %s]' %self.value
+
+    def to_geotiff(self):
+        pass
+        #return "StdParallel2"
+    
+##+lat_ts    Latitude of true scale
+class LatitudeTrueScale:
+    proj4 = "lat_ts"
+    ogc_wkt = "Standard_Parallel_1"
+    esri_wkt = "Standard_Parallel_1"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+lat_ts=%s" %self.value
+
+    def to_ogc_wkt(self):
+        return 'PARAMETER["Standard_Parallel_1", %s]' %self.value
+
+    def to_esri_wkt(self):
+        return 'PARAMETER["Standard_Parallel_1", %s]' %self.value
+
+    def to_geotiff(self):
+        pass
+        #return "ProjStdParallel1"
+    
+##+lon_0     Central meridian
+class CentralMeridian:
+    proj4 = "+lon_0"
+    ogc_wkt = "Central_Meridian"
+    esri_wkt = "Central_Meridian"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+lon_0=%s" %self.value
+
+    def to_ogc_wkt(self):
+        return 'PARAMETER["Central_Meridian", %s]' %self.value
+
+    def to_esri_wkt(self):
+        return 'PARAMETER["Central_Meridian", %s]' %self.value
+
+    def to_geotiff(self):
+        pass
+        #return "ProjCenterLong"
+
+##+lonc      ? Longitude used with Oblique Mercator and possibly a few others
+class LongitudeCenter:
+    proj4 = "+lonc"
+    ogc_wkt = "Longitude_Of_Center"
+    esri_wkt = "Longitude_Of_Center"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+lonc=%s" %self.value
+
+    def to_ogc_wkt(self):
+        return 'PARAMETER["Longitude_Of_Center", %s]' %self.value
+
+    def to_esri_wkt(self):
+        return 'PARAMETER["Longitude_Of_Center", %s]' %self.value
+    
+##+lon_wrap  Center longitude to use for wrapping (see below)
+    
+##+over      Allow longitude output outside -180 to 180 range, disables wrapping (see below)
+
+##+pm        Alternate prime meridian (typically a city name, see below)
+class PrimeMeridian:
+    proj4 = "+pm"
+    ogc_wkt = "PRIMEM"
+    esri_wkt = "PRIMEM"
+    
+    def __init__(self, value):
+        """
+        Arguments:
+
+        - **value**: Longitude value relative to Greenwich. 
+        """
+        self.value = value
+
+    def to_proj4(self):
+        return "+pm=%s" %self.value
+
+    def to_ogc_wkt(self):
+        return 'PRIMEM["Greenwich", %s]' %self.value
+
+    def to_esri_wkt(self):
+        return 'PRIMEM["Greenwich", %s]' %self.value
+
+##+proj      Projection name (see `proj -l`)
+class Projection:
+    proj4 = "+proj"
+    ogc_wkt = "PROJECTION"
+    esri_wkt = "PROJECTION"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+proj=%s" %self.value.proj4
+
+    def to_ogc_wkt(self):
+        return 'PROJECTION["%s"]' %self.value.ogc_wkt
+
+    def to_esri_wkt(self):
+        return 'PROJECTION["%s"]' %self.value.esri_wkt
+
+##+zone     UTM zone
+    
+##+south     Denotes southern hemisphere UTM zone
+    
+##+towgs84   3 or 7 term datum transform parameters (see below)
+class DatumShift:
+    proj4 = "+towgs84"
+    ogc_wkt = "TOWGS84"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+towgs84=%s" %",".join((bytes(val) for val in self.value))
+
+    def to_ogc_wkt(self):
+        return "TOWGS84[%s]" %",".join((bytes(val) for val in self.value))
+
+    def to_esri_wkt(self):
+        raise Exception("Paramater not supported by ESRI WKT")
+    
+##+to_meter  Multiplier to convert map units to 1.0m
+class MeterMultiplier:
+    proj4 = "+to_meter"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+to_meter=%s" %self.value
+
+    def to_ogc_wkt(self):
+        # the stuff that comes after UNITS["meter", ... # must be combined with unittype in a unit class to make wkt
+        return bytes(self.value)
+
+    def to_esri_wkt(self):
+        return bytes(self.value)
+
+##+units     meters, US survey feet, etc.
+class UnitType:
+    proj4 = "+units"
+    
+    def __init__(self, value):
+        """
+        Arguments:
+
+        - **value**: A specific unit type instance, eg Meter(). 
+        """
+        self.value = value
+
+    def to_proj4(self):
+        return "+units=%s" %self.value.proj4
+
+    def to_ogc_wkt(self):
+        # the stuff that comes after UNITS[... # must be combined with metermultiplier in a unit class to make wkt
+        return bytes(self.value.ogc_wkt)
+
+    def to_esri_wkt(self):
+        return bytes(self.value.esri_wkt)
+
+# special...
+class Unit:
+    ogc_wkt = "UNIT"
+    esri_wkt = "UNIT"
+    
+    def __init__(self, unittype, metermultiplier):
+        self.unittype = unittype
+        self.metermultiplier = metermultiplier
+
+    def to_proj4(self):
+        return "%s %s" %(self.unittype.to_proj4(), self.metermultiplier.to_proj4())
+
+    def to_ogc_wkt(self):
+        return 'UNIT["%s", %s]' %(self.unittype.to_ogc_wkt(), self.metermultiplier.to_ogc_wkt())
+
+    def to_esri_wkt(self):
+        return 'UNIT["%s", %s]' %(self.unittype.to_esri_wkt(), self.metermultiplier.to_esri_wkt())
+
+# angular unit
+class AngularUnit:
+    ogc_wkt = "UNIT"
+    esri_wkt = "UNIT"
+    
+    def __init__(self, unittype, metermultiplier):
+        self.unittype = unittype
+        self.metermultiplier = metermultiplier
+
+    def to_proj4(self):
+        # cannot be specified in proj4, so just return nothing
+        return ""
+
+    def to_ogc_wkt(self):
+        return 'UNIT["%s", %s]' %(self.unittype.to_ogc_wkt(), self.metermultiplier.to_ogc_wkt())
+
+    def to_esri_wkt(self):
+        return 'UNIT["%s", %s]' %(self.unittype.to_esri_wkt(), self.metermultiplier.to_esri_wkt())
+    
+##+x_0       False easting
+class FalseEasting:
+    proj4 = "+x_0"
+    esri_wkt = "False_Easting"
+    ogc_wkt = "false_easting"
+    geotiff = "FalseEasting"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+x_0=%s" %self.value
+
+    def to_ogc_wkt(self):
+        return 'PARAMETER["false_easting", %s]' % self.value
+
+    def to_esri_wkt(self):
+        return 'PARAMETER["False_Easting", %s]' % self.value
+    
+##+y_0       False northing
+class FalseNorthing:
+    proj4 = "+y_0"
+    esri_wkt = "False_Northing"
+    ogc_wkt = "false_northing"
+    geotiff = "FalseNorthing"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+y_0=%s" %self.value
+
+    def to_ogc_wkt(self):
+        return 'PARAMETER["false_northing", %s]' % self.value
+
+    def to_esri_wkt(self):
+        return 'PARAMETER["False_Northing", %s]' % self.value
+
+##+h       Satellite height
+class SatelliteHeight:
+    proj4 = "+h"
+    ogc_wkt = "satellite_height"
+    esri_wkt = "satellite_height"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+h=%s" %self.value
+
+    def to_ogc_wkt(self):
+        return 'PARAMETER["satellite_height", %s]' % self.value
+
+    def to_esri_wkt(self):
+        return 'PARAMETER["satellite_height", %s]' % self.value
+
+##+tilt     Tilt angle
+class TiltAngle:
+    proj4 = "+tilt"
+    
+    def __init__(self, value):
+        self.value = value
+
+    def to_proj4(self):
+        return "+tilt=%s" %self.value
+
+    def to_ogc_wkt(self):
+        raise Exception("Parameter not supported by OGC WKT")
+
+    def to_esri_wkt(self):
+        raise Exception("Parameter not supported by ESRI WKT")
+
+    
+# then the final CRS object which is instantiated with all of these?
+# remember to use +no_defs when outputting to proj4
+# ...
+class CRS:
+    def __init__(self, toplevel):
+        self.toplevel = toplevel
+        
+    def to_proj4(self):
+        if isinstance(self.toplevel, ProjCS):
+            return "%s +no_defs" % self.toplevel.to_proj4()
+        elif isinstance(self.toplevel, GeogCS):
+            return "+proj=longlat %s +no_defs" % self.toplevel.to_proj4()
+
+    def to_ogc_wkt(self):
+        return "%s" % self.toplevel.to_ogc_wkt()
+
+    def to_esri_wkt(self):
+        return "%s" % self.toplevel.to_esri_wkt()
+
+

pycrs/elements/projections.py

@@ -0,0 +1,173 @@
+
+
+def find(projname, crstype, strict=False):
+    if not strict:
+        projname = projname.lower()
+    for itemname,item in globals().items():
+        if itemname.startswith("_"):
+            continue
+        try:
+            if hasattr(item, crstype):
+                itemname = getattr(item, crstype)
+                if not strict:
+                    itemname = itemname.lower()
+                if projname == itemname:
+                    return item
+        except:
+            pass
+    else:
+        return None
+
+
+
+    
+
+class Robinson:
+    proj4 = "robin"
+    ogc_wkt = "Robinson"
+    esri_wkt = "Robinson"
+
+class UTM:
+    proj4 = "utm"
+    ogc_wkt = "Transverse_Mercator"
+    esri_wkt = "Transverse_Mercator"
+
+class ObliqueMercator:
+    proj4 = "omerc"
+    ogc_wkt = "Hotine_Oblique_Mercator"
+    esri_wkt = "Hotine_Oblique_Mercator_Azimuth_Natural_Origin"
+    
+class AlbersEqualArea:
+    proj4 = "aea"
+    ogc_wkt = "Albers_Conic_Equal_Area"
+    esri_wkt = "Albers"
+
+class CylindricalEqualArea:
+    proj4 = "cea"
+    ogc_wkt = "Cylindrical_Equal_Area"
+    esri_wkt = "Cylindrical_Equal_Area"
+    
+class EquiDistantConic:
+    proj4 = "eqdc"
+    ogc_wkt = "Equidistant_Conic"
+    esri_wkt = "Equidistant_Conic"
+
+class TransverseMercator:
+    proj4 = "tmerc"
+    ogc_wkt = "Transverse_Mercator"
+    esri_wkt = "Transverse_Mercator"
+
+class GallStereographic:
+    proj4 = "gall"
+    ogc_wkt = "Gall_Stereographic"
+    esri_wkt = "Gall_Stereographic"
+
+class Gnomonic:
+    proj4 = "gnom"
+    ogc_wkt = "Gnomonic"
+    esri_wkt = "Gnomonic"
+
+class LambertAzimuthalEqualArea:
+    proj4 = "laea"
+    ogc_wkt = "Lambert_Azimuthal_Equal_Area"
+    esri_wkt = "Lambert_Azimuthal_Equal_Area"
+
+class MillerCylindrical:
+    proj4 = "mill"
+    ogc_wkt = "Miller_Cylindrical"
+    esri_wkt = "Miller_Cylindrical"
+
+class Mollweide:
+    proj4 = "moll"
+    ogc_wkt = "Mollweide"
+    esri_wkt = "Mollweide"
+
+class ObliqueStereographic:
+    proj4 = "sterea"
+    ogc_wkt = "Oblique_Stereographic"
+    esri_wkt = "Stereographic_North_Pole"
+
+class Orthographic:
+    proj4 = "ortho"
+    ogc_wkt = "Orthographic"
+    esri_wkt = "Orthographic"
+
+class PolarStereographic:
+    proj4 = "stere"
+    ogc_wkt = "Polar_Stereographic" # could also be just stereographic
+    esri_wkt = "Stereographic" # but also spelled with additional _South/North_Pole, for the same projection and diff params (maybe just for humans)?...
+
+class Sinusoidal:
+    proj4 = "sinu"
+    ogc_wkt = "Sinusoidal"
+    esri_wkt = "Sinusoidal"
+
+class VanDerGrinten:
+    proj4 = "vandg"
+    ogc_wkt = "VanDerGrinten"
+    esri_wkt = "Van_der_Grinten_I"
+
+class Equirectangular:
+    proj4 = "eqc"
+    ogc_wkt = "Equirectangular"
+    esri_wkt = "Equidistant_Cylindrical"
+
+class LambertConformalConic:
+    proj4 = "lcc"
+    ogc_wkt = "Lambert_Conformal_Conic" # possible has some variants
+    esri_wkt = "Lambert_Conformal_Conic"
+
+class Krovak:
+    proj4 = "krovak"
+    ogc_wkt = "Krovak"
+    esri_wkt = "Krovak"
+
+class NearSidedPerspective:
+    proj4 = "nsper"
+    ogc_wkt = "Near_sided_perspective"
+    esri_wkt = "Near_sided_perspective" # not confirmed
+
+class TiltedPerspective:
+    proj4 = "tsper"
+    ogc_wkt = "Tilted_perspective"
+    esri_wkt = "Tilted_perspective" # not confirmed
+
+class InteruptedGoodeHomolosine:
+    proj4 = "igh"
+    ogc_wkt = "Interrupted_Goodes_Homolosine"
+    esri_wkt = "Interrupted_Goodes_Homolosine"
+
+class Larrivee:
+    proj4 = "larr"
+    ogc_wkt = "Larrivee"
+    esri_wkt = "Larrivee" # not confirmed
+
+class LamberEqualAreaConic:
+    proj4 = "leac"
+    ogc_wkt = "Lambert_Equal_Area_Conic"
+    esri_wkt = "Lambert_Equal_Area_Conic" # not confirmed
+
+class Mercator:
+    proj4 = "merc"
+    ogc_wkt = "Mercator" # has multiple varieties
+    esri_wkt = "Mercator"
+
+class ObliqueCylindricalEqualArea:
+    proj4 = "ocea"
+    ogc_wkt = "Oblique_Cylindrical_Equal_Area"
+    esri_wkt = "Oblique_Cylindrical_Equal_Area"
+
+        
+
+
+
+
+
+
+
+
+    
+
+    
+
+

pycrs/elements/units.py

@@ -0,0 +1,41 @@
+
+
+def find(unitname, crstype, strict=False):
+    if not strict:
+        unitname = unitname.lower()
+    for itemname,item in globals().items():
+        if itemname.startswith("_"):
+            continue
+        try:
+            if hasattr(item, crstype):
+                itemname = getattr(item, crstype)
+                # compare
+                if not strict:
+                    itemname = itemname.lower()
+                if unitname == itemname:
+                    return item
+                # special handling of wkt meters which has multiple possibilities
+                elif isinstance(item(), Meter) and crstype.endswith("wkt") and not strict and unitname in ("meters","meter","metre"):
+                    return item
+        except:
+            pass
+    else:
+        return None
+
+
+
+
+class Meter:
+    proj4 = "m"
+    ogc_wkt = "Meters" # or is it metre?? sometimes even Meter?
+    esri_wkt = "Meter"
+
+class Degree:
+    proj4 = "degrees"
+    ogc_wkt = "degree"
+    esri_wkt = "Degree"
+
+class Feet:
+    proj4 = "..."
+    ogc_wkt = "Foot_US"
+    esri_wkt = "Foot_US"