def write_vector_data(data, projection, geometry, filename, keywords=None):
"""Write point data and any associated attributes to vector file
Input:
data: List of N dictionaries each with M fields where
M is the number of attributes.
A value of None is acceptable.
projection: WKT projection information
geometry: List of points or polygons.
filename: Output filename
keywords: Optional dictionary
Note: The only format implemented is GML and SHP so the extension
must be either .gml or .shp
# FIXME (Ole): When the GML driver is used,
# the spatial reference is not stored.
# I suspect this is a bug in OGR.
Background:
* http://www.gdal.org/ogr/ogr_apitut.html (last example)
* http://invisibleroads.com/tutorials/gdal-shapefile-points-save.html
"""
V = Vector(data, projection, geometry, keywords=keywords)
V.write_to_file(filename)
def write_vector_data(data, projection, geometry, filename, keywords=None):
"""Write point data and any associated attributes to vector file
Input:
data: List of N dictionaries each with M fields where
M is the number of attributes.
A value of None is acceptable.
projection: WKT projection information
geometry: List of points or polygons.
filename: Output filename
keywords: Optional dictionary
Note: The only format implemented is GML and SHP so the extension
must be either .gml or .shp
# FIXME (Ole): When the GML driver is used,
# the spatial reference is not stored.
# I suspect this is a bug in OGR.
Background:
* http://www.gdal.org/ogr/ogr_apitut.html (last example)
* http://invisibleroads.com/tutorials/gdal-shapefile-points-save.html
"""
V = Vector(data, projection, geometry, keywords=keywords)
V.write_to_file(filename)
def csv2shp(path, lonname='Bujur', latname='Lintang'):
# Read csv data
reader = csv.DictReader(open(path, 'r'))
data = []
for x in reader:
data.append(x)
# Determine latitude and longitude fields
fieldnames = reader.fieldnames
msg = ('Could not find requested longitude "%s" in %s. Available '
'field names are: %s' % (lonname, path, str(fieldnames)))
assert lonname in fieldnames, msg
msg = ('Could not find requested latitude "%s" in %s. Available '
'field names are: %s' % (latname, path, str(fieldnames)))
assert latname in fieldnames, msg
# Extract point geometry
lon = [float(x[lonname]) for x in data]
lat = [float(x[latname]) for x in data]
geometry = zip(lon, lat)
# Replace spaces in attribute names with underscores (issue #177)
for i, D in enumerate(data):
D_clean = {}
for key in D:
D_clean[key.replace(' ', '_')] = D[key]
data[i] = D_clean
# Create vector object
V = Vector(data=data,
projection=DEFAULT_PROJECTION,
geometry=geometry)
# Write as shapefile
basename, _ = os.path.splitext(path)
V.write_to_file(basename + '.shp')
fid = open(basename + '.keywords', 'w')
fid.write('category:exposure\n')
fid.write('subcategory:building\n')
fid.write('datatype:sigab\n')
fid.close()
def csv2shp(path, lonname='Bujur', latname='Lintang'):
# Read csv data
reader = csv.DictReader(open(path, 'r'))
data = []
for x in reader:
data.append(x)
# Determine latitude and longitude fields
fieldnames = reader.fieldnames
msg = ('Could not find requested longitude "%s" in %s. Available '
'field names are: %s' % (lonname, path, str(fieldnames)))
assert lonname in fieldnames, msg
msg = ('Could not find requested latitude "%s" in %s. Available '
'field names are: %s' % (latname, path, str(fieldnames)))
assert latname in fieldnames, msg
# Extract point geometry
lon = [float(x[lonname]) for x in data]
lat = [float(x[latname]) for x in data]
geometry = zip(lon, lat)
# Replace spaces in attribute names with underscores (issue #177)
for i, D in enumerate(data):
D_clean = {}
for key in D:
D_clean[key.replace(' ', '_')] = D[key]
data[i] = D_clean
# Create vector object
V = Vector(data=data, projection=DEFAULT_PROJECTION, geometry=geometry)
# Write as shapefile
basename, _ = os.path.splitext(path)
V.write_to_file(basename + '.shp')
fid = open(basename + '.keywords', 'w')
fid.write('category:exposure\n')
fid.write('subcategory:building\n')
fid.write('datatype:sigab\n')
fid.close()
def test_vector_class(self):
"""Consistency of vector class for point data
"""
# Read data file
layername = 'lembang_schools.shp'
filename = '%s/%s' % (TESTDATA, layername)
V = read_layer(filename)
# Make a smaller dataset
V_ref = V.get_topN('FLOOR_AREA', 5)
geometry = V_ref.get_geometry()
data = V_ref.get_data()
projection = V_ref.get_projection()
# Create new object from test data
V_new = Vector(data=data, projection=projection, geometry=geometry)
# Check
assert V_new == V_ref
assert not V_new != V_ref
# Write this new object, read it again and check
tmp_filename = unique_filename(suffix='.shp')
V_new.write_to_file(tmp_filename)
V_tmp = read_layer(tmp_filename)
assert V_tmp == V_ref
assert not V_tmp != V_ref
# Check that equality raises exception when type is wrong
try:
V_tmp == Raster()
except TypeError:
pass
else:
msg = 'Should have raised TypeError'
raise Exception(msg)
