Files
PyCRS/pycrs/parser.py
T
Karim Bahgat a8aad24a13 Added almost all params, made front API usable, and added crs transform draw testing.
Next step figure out more stable proj4 parsing of datums and proj etc,
with adding more specific names.
Then consistently make to_esriwkt work.
2015-06-30 04:14:12 +02:00

345 lines
10 KiB
Python

# parse from text strings
# possible use module: https://github.com/rockdoc/grabbag/wiki/CRS-WKT-Parser
# also note some paramter descriptions: http://www.geoapi.org/3.0/javadoc/org/opengis/referencing/doc-files/WKT.html
# and see gdal source code: http://gis.stackexchange.com/questions/129764/how-are-esri-wkt-projections-different-from-ogc-wkt-projections
from . import datums
from . import ellipsoids
from . import parameters
from . import units
from . import projections
from . import webscrape
def from_epsg_code(code):
# must go online (or look up local table) to get crs details
code = str(code)
proj4 = webscrape.crscode_to_string("epsg", code, "proj4")
crs = from_proj4(proj4)
return crs
def from_esri_code(code):
# must go online (or look up local table) to get crs details
code = str(code)
proj4 = webscrape.crscode_to_string("esri", code, "proj4")
crs = from_proj4(proj4)
return crs
def from_sr_code(code):
# must go online (or look up local table) to get crs details
code = str(code)
proj4 = webscrape.crscode_to_string("sr-org", code, "proj4")
crs = from_proj4(proj4)
return crs
##def from_esri_wkt(string):
## # parse arguments into components
## # use args to create crs
## pass
##
##def from_ogc_wkt(string):
## # parse arguments into components
## # use args to create crs
## pass
##
##def from_unknown_wkt(string):
## # detect if ogc wkt or esri wkt
## # TIPS: esri wkt datums all use "D_" before the datum name
## # then load with appropriate function
## pass
def from_proj4(string):
# parse arguments into components
# use args to create crs
# SLIGTHLY MESSY STILL, CLEANUP..
params = []
partdict = dict([part.split("=") for part in string.split()
if not part.startswith("+no_defs")])
# INIT CODES...?
# eg, +init=epsg code...?
# DATUM
# datum param is required
if "+datum" in partdict:
# get predefined datum def
if partdict["+datum"] == "WGS84":
datumdef = datums.WGS84()
elif partdict["+datum"] == "NAD83":
datumdef = datums.NAD83()
else:
datumdef = datums.Unknown()
else:
datumdef = datums.Unknown()
# ELLIPS
# ellipse param is required
if "+ellps" in partdict:
# get predefined ellips def
if partdict["+ellps"] == "WGS84":
ellipsdef = ellipsoids.WGS84()
elif partdict["+ellps"] == "WGS72":
ellipsdef = ellipsoids.WGS72()
elif partdict["+ellps"] == "intl":
ellipsdef = ellipsoids.International()
elif partdict["+ellps"] == "GRS80":
ellipsdef = ellipsoids.GRS80()
else:
raise Exception("Could not find required +ellps element")
# TO WGS 84 COEFFS
if "+towgs84" in partdict:
coeffs = partdict["+towgs84"].split(",")
datumshift = parameters.DatumShift(coeffs)
# if no datum, use ellips + towgs84 params to create the correct datum
# ...??
# COMBINE DATUM AND ELLIPS
## create datum and ellips param objs
ellips = parameters.Ellipsoid(ellipsdef,
semimaj_ax=partdict.get("+a"),
inv_flat=partdict.get("+f"))
if "+datum" in partdict:
datum = parameters.Datum(datumdef, ellips)
elif "+towgs84" in partdict:
datum = parameters.Datum(datumdef, ellips, datumshift)
else:
datum = parameters.Datum(datumdef, ellips)
# PRIME MERIDIAN
# set default
prime_mer = parameters.PrimeMeridian(0)
# overwrite with user input
if "+pm" in partdict:
# for now only support longitude, later add name support from below:
## greenwich 0dE
## lisbon 9d07'54.862"W
## paris 2d20'14.025"E
## bogota 74d04'51.3"E
## madrid 3d41'16.48"W
## rome 12d27'8.4"E
## bern 7d26'22.5"E
## jakarta 106d48'27.79"E
## ferro 17d40'W
## brussels 4d22'4.71"E
## stockholm 18d3'29.8"E
## athens 23d42'58.815"E
## oslo 10d43'22.5"E
prime_mer = parameters.PrimeMeridian(partdict["+pm"])
# ANGULAR UNIT
## proj4 cannot set angular unit, so just set to default
metmulti = parameters.MeterMultiplier(0.017453292519943295)
unittype = parameters.UnitType(units.Degree())
angunit = parameters.AngularUnit(unittype, metmulti)
# GEOGCS (note, currently does not load axes)
geogcs = parameters.GeogCS("Unknown", datum, prime_mer, angunit) #, twin_ax)
# PROJECTION
if "+proj" in partdict:
# get predefined proj def
if partdict["+proj"] == "robin":
projdef = projections.Robinson()
elif partdict["+proj"] == "omerc":
projdef = projections.ObliqueMercator()
elif partdict["+proj"] == "longlat":
projdef = None
# set geogcs axis in correct order
elif partdict["+proj"] == "latlong":
projdef = None
# set geogcs axis in correct order
# ALSO SHOULDNT EXCLUDE +proj, NEED WAY TO INCLUDE IT...
# ...
else:
projdef = None
else:
raise Exception("Could not find required +proj element")
if projdef:
# create proj param obj
proj = parameters.Projection(projdef)
# CENTRAL MERIDIAN
if "+lon_0" in partdict:
val = partdict["+lon_0"]
obj = parameters.CentralMeridian(val)
params.append(obj)
# FALSE EASTING
if "+x_0" in partdict:
val = partdict["+x_0"]
obj = parameters.FalseEasting(val)
params.append(obj)
# FALSE NORTHING
if "+y_0" in partdict:
val = partdict["+y_0"]
obj = parameters.FalseNorthing(val)
params.append(obj)
# SCALING FACTOR
if "+k_0" in partdict or "+k" in partdict:
if "+k_0" in partdict: val = partdict["+k_0"]
elif "+k" in partdict: val = partdict["+k"]
obj = parameters.ScalingFactor(val)
params.append(obj)
# LATITUDE ORIGIN
if "+lat_0" in partdict:
val = partdict["+lat_0"]
obj = parameters.LatitudeOrigin(val)
params.append(obj)
# LATITUDE TRUE SCALE
if "+lat_ts" in partdict:
val = partdict["+lat_ts"]
obj = parameters.LatitudeTrueScale(val)
params.append(obj)
# LONGITUDE CENTER
if "+lonc" in partdict:
val = partdict["+lonc"]
obj = parameters.LongitudeCenter(val)
params.append(obj)
# AZIMUTH
if "+alpha" in partdict:
val = partdict["+alpha"]
obj = parameters.Azimuth(val)
params.append(obj)
# STD PARALLEL 1
if "+lat1" in partdict:
val = partdict["+lat1"]
obj = parameters.LatitudeFirstStndParallel(val)
params.append(obj)
# STD PARALLEL 2
if "+lat2" in partdict:
val = partdict["+lat2"]
obj = parameters.LatitudeSecondStndParallel(val)
params.append(obj)
# UNIT
## set default
metmulti = parameters.MeterMultiplier(1.0)
unittype = parameters.UnitType(units.Meter())
## override with user input
if "+to_meter" in partdict:
metmulti = parameters.MeterMultiplier(partdict["+to_meter"])
if "+units" in partdict:
if partdict["+units"] == "m":
unittype = parameters.UnitType(units.Meter())
## create unitobj
unit = parameters.Unit(unittype, metmulti)
# PROJCS
projcs = parameters.ProjCS("Unknown", geogcs, proj, params, unit)
# CRS
crs = parameters.CRS(projcs)
else:
crs = parameters.CRS(geogcs)
# FINISHED
return crs
##def from_ogc_urn(string):
## # hmmm, seems like ogc urn could be anything incl online link, epsg, etc...
## # if necessary, must go online (or lookup local table) to get details
## # maybe test which of these and run their function?
## # examples urn:ogc:def:crs:OGC:1.3:CRS1
## # or with EPSG instead of OGC
##
## # If OGC, 1.3 is pdf version, and after that is a name from list below
## # as found in pdf: "Definition identifier URNs in OGC namespace"
## # OGC crs definitions
## # URN | CRS name | Definition reference
## # urn:ogc:def:crs:OGC:1.3:CRS1 Map CS B.2 in OGC 06-042
## # urn:ogc:def:crs:OGC:1.3:CRS84 WGS 84 longitude-latitude B.3 in OGC 06-042
## # urn:ogc:def:crs:OGC:1.3:CRS83 NAD83 longitude-latitude B.4 in OGC 06-042
## # urn:ogc:def:crs:OGC:1.3:CRS27 NAD27 longitude-latitude B.5 in OGC 06-042
## # urn:ogc:def:crs:OGC:1.3:CRS88 NAVD 88 B.6 in OGC 06-042
## # urn:ogc:def:crs:OGC:1.3:AUTO42001:99:8888 Auto universal transverse mercator B.7 in OGC 06-042
## # urn:ogc:def:crs:OGC:1.3:AUTO42002:99:8888 Auto transverse mercator B.8 in OGC 06-042
## # urn:ogc:def:crs:OGC:1.3:AUTO42003:99:8888 Auto orthographic B.9 in OGC 06-042
## # urn:ogc:def:crs:OGC:1.3:AUTO42004:99:8888 Auto equirectangular B.10 in OGC 06-042
## # urn:ogc:def:crs:OGC:1.3:AUTO42005:99 Auto Mollweide B.11 in OGC 06-042
##
## pass
def from_unknown_text(text):
"""Detect type and load with appropriate function"""
if string.startswith("urn:"):
from_ogc_urn(string)
elif string.startswith("+proj="):
from_proj4(string)
elif string.startswith("PROJCS["):
from_unknown_wkt(string)
elif string.startswith("EPSG:"):
from_epsg_code(string.split(":")[1])
elif string.startswith("ESRI:"):
from_esri_code(string.split(":")[1])
elif string.startswith("SR-ORG:"):
from_sr_code(string.split(":")[1])
else: raise Exception("Could not detect which type of crs")
##def from_geotiff_parameters(**params):
## pass