def toCurveGrid(self, gridid=None):
"""Convert to a curvilinear grid.
'gridid' is the string identifier of the resulting curvilinear grid object.
"""
from coord import TransientVirtualAxis, TransientAxis2D
from hgrid import TransientCurveGrid
lat = self._lataxis_[:]
latunits = self._lataxis_.units
lon = self._lonaxis_[:]
lonunits = self._lonaxis_.units
blat, blon = self.getBounds()
mask = self.getMask()
nlat = len(lat)
nlon = len(lon)
centerLat = numpy.repeat(lat[:,numpy.newaxis], nlon, axis=1)
centerLon = numpy.repeat(lon[numpy.newaxis,:], nlat, axis=0)
# Create corner latitudes, ensuring counterclockwise direction
clat = numpy.zeros((nlat, 4), numpy.float)
if (blat[0,0]<= blat[0,1]):
incr = 1
else:
incr = 0
clat[:,0] = blat[:,1-incr]
clat[:,1] = blat[:,1-incr]
clat[:,2] = blat[:,incr]
clat[:,3] = blat[:,incr]
cornerLat = numpy.repeat(clat[:,numpy.newaxis,:], nlon, axis=1)
# Create corner longitudes, ensuring counterclockwise direction
clon = numpy.zeros((nlon, 4), numpy.float)
if (blon[0,0]<= blon[0,1]):
incr = 1
else:
incr = 0
clon[:,0] = blon[:,1-incr]
clon[:,1] = blon[:,incr]
clon[:,2] = blon[:,incr]
clon[:,3] = blon[:,1-incr]
cornerLon = numpy.repeat(clon[numpy.newaxis,:,:], nlat, axis=0)
iaxis = TransientVirtualAxis("i",nlat)
jaxis = TransientVirtualAxis("j",nlon)
lataxis = TransientAxis2D(centerLat, axes=(iaxis, jaxis), bounds=cornerLat,
attributes={'units':latunits}, id="latitude")
lonaxis = TransientAxis2D(centerLon, axes=(iaxis, jaxis), bounds=cornerLon,
attributes={'units':lonunits}, id="longitude")
grid = TransientCurveGrid(lataxis, lonaxis, id=gridid, tempmask=mask)
return grid
def readScripCurveGrid(fileobj, dims, whichType, whichGrid):
"""Read a 'native' SCRIP grid file, returning a transient curvilinear grid.
fileobj is an open CDMS dataset or file object.
dims is the grid shape.
whichType is the type of file, either "grid" or "mapping"
if whichType is "mapping", whichGrid is the choice of grid, either "source" or "destination"
"""
import string
from coord import TransientAxis2D
if 'S' in fileobj.variables.keys():
if whichType == "grid":
gridCornerLatName = 'grid_corner_lat'
gridCornerLonName = 'grid_corner_lon'
gridMaskName = 'grid_imask'
gridCenterLatName = 'grid_center_lat'
gridCenterLonName = 'grid_center_lon'
titleName = 'title'
elif whichGrid == "destination":
gridCornerLatName = 'yv_b'
gridCornerLonName = 'xv_b'
gridMaskName = 'mask_b'
gridCenterLatName = 'yc_b'
gridCenterLonName = 'xc_b'
titleName = 'dest_grid'
else:
gridCornerLatName = 'yv_a'
gridCornerLonName = 'xv_a'
gridMaskName = 'mask_a'
gridCenterLatName = 'yc_a'
gridCenterLonName = 'xc_a'
titleName = 'source_grid'
else:
if whichType == "grid":
gridCornerLatName = 'grid_corner_lat'
gridCornerLonName = 'grid_corner_lon'
gridMaskName = 'grid_imask'
gridCenterLatName = 'grid_center_lat'
gridCenterLonName = 'grid_center_lon'
titleName = 'title'
elif whichGrid == "destination":
gridCornerLatName = 'dst_grid_corner_lat'
gridCornerLonName = 'dst_grid_corner_lon'
gridMaskName = 'dst_grid_imask'
gridCenterLatName = 'dst_grid_center_lat'
gridCenterLonName = 'dst_grid_center_lon'
titleName = 'dest_grid'
else:
gridCornerLatName = 'src_grid_corner_lat'
gridCornerLonName = 'src_grid_corner_lon'
gridMaskName = 'src_grid_imask'
gridCenterLatName = 'src_grid_center_lat'
gridCenterLonName = 'src_grid_center_lon'
titleName = 'source_grid'
vardict = fileobj.variables
cornerLat = fileobj(gridCornerLatName)
cornerLon = fileobj(gridCornerLonName)
ncorners = cornerLat.shape[-1]
ni = dims[1]
nj = dims[0]
gridshape = (ni, nj)
boundsshape = (ni, nj, ncorners)
if hasattr(cornerLat, 'units') and string.lower(
cornerLat.units)[0:6] == 'radian':
cornerLat = (cornerLat * (180.0 / numpy.pi)).reshape(boundsshape)
cornerLon = (cornerLon * (180.0 / numpy.pi)).reshape(boundsshape)
else:
cornerLat = cornerLat.reshape(boundsshape)
cornerLon = cornerLon.reshape(boundsshape)
iaxis = TransientVirtualAxis("i", ni)
jaxis = TransientVirtualAxis("j", nj)
if vardict.has_key(gridMaskName):
# SCRIP convention: 0 for invalid data
# numpy.ma convention: 1 for invalid data
mask = 1 - fileobj(gridMaskName)
mask = mask.reshape(gridshape)
else:
mask = None
if vardict.has_key(gridCenterLatName):
centerLat = fileobj(gridCenterLatName).reshape(gridshape)
gclat = fileobj[gridCenterLatName]
if hasattr(gclat, "units") and string.lower(gclat.units) == 'radians':
centerLat *= (180.0 / numpy.pi)
else:
centerLat = cornerLat[:, :, 0]
if vardict.has_key(gridCenterLonName):
centerLon = fileobj(gridCenterLonName).reshape(gridshape)
gclon = fileobj[gridCenterLonName]
if hasattr(gclon, "units") and string.lower(gclon.units) == 'radians':
centerLon *= (180.0 / numpy.pi)
else:
centerLon = cornerLon[:, :, 0]
if hasattr(fileobj, titleName):
gridid = getattr(fileobj, titleName)
gridid = string.replace(string.strip(gridid), ' ', '_')
else:
gridid = "<None>"
lataxis = TransientAxis2D(centerLat,
axes=(iaxis, jaxis),
bounds=cornerLat,
attributes={'units': 'degrees_north'},
id="latitude")
lonaxis = TransientAxis2D(centerLon,
axes=(iaxis, jaxis),
bounds=cornerLon,
attributes={'units': 'degrees_east'},
id="longitude")
grid = TransientCurveGrid(lataxis, lonaxis, id=gridid, tempmask=mask)
return grid
def toCurveGrid(self, gridid=None):
"""Convert to a curvilinear grid.
'gridid' is the string identifier of the resulting curvilinear grid object.
"""
from coord import TransientVirtualAxis, TransientAxis2D
from hgrid import TransientCurveGrid
lat = self._lataxis_[:]
lon = self._lonaxis_[:]
latunits = ''
if hasattr(self._lataxis_, 'units'):
latunits = self._lataxis_.units
lonunits = ''
if hasattr(self._lonaxis_, 'units'):
lonunits = self._lonaxis_.units
blat, blon = self.getBounds()
mask = self.getMask()
nlat = len(lat)
nlon = len(lon)
order = self.getOrder()
# Deal with the order of the axes
# ax - first index, ay - second index
if re.search(order, 'xy', re.I):
orderXY = True
ax, ay = lat, lon
bx, by = blat, blon
nx, ny = nlat, nlon
else:
orderXY = False
ax, ay = lon, lat
bx, by = blon, blat
nx, ny = nlon, nlat
centerX = numpy.outer(numpy.ones(ny), ax)
centerY = numpy.outer(ay, numpy.ones(nx))
# Create corner latitudes (in yx order), ensuring counterclockwise direction
cy = numpy.zeros((ny, 4), numpy.float)
if (by[0, 0] <= by[0, 1]):
incr = 1
else:
incr = 0
cy[:, 0] = by[:, 1 - incr]
cy[:, 1] = by[:, 1 - incr]
cy[:, 2] = by[:, incr]
cy[:, 3] = by[:, incr]
cornerY = numpy.repeat(cy[:, numpy.newaxis, :], nx, axis=1)
# Create corner longitudes (in yx order), ensuring counterclockwise direction
cx = numpy.zeros((nx, 4), numpy.float)
if (bx[0, 0] <= bx[0, 1]):
incr = 1
else:
incr = 0
cx[:, 0] = bx[:, 1 - incr]
cx[:, 1] = bx[:, incr]
cx[:, 2] = bx[:, incr]
cx[:, 3] = bx[:, 1 - incr]
cornerX = numpy.repeat(cx[numpy.newaxis, :, :], ny, axis=0)
iaxis = TransientVirtualAxis("i", ny) # First axis
jaxis = TransientVirtualAxis("j", nx) # Second axis
centerLat = centerY
centerLon = centerX
cornerLat = cornerY
cornerLon = cornerX
if orderXY:
centerLat = centerX
centerLon = centerY
cornerLat = cornerX
cornerLon = cornerY
lataxis = TransientAxis2D(centerLat,
axes=(iaxis, jaxis),
bounds=cornerLat,
attributes={'units': latunits},
id="latitude")
lonaxis = TransientAxis2D(centerLon,
axes=(iaxis, jaxis),
bounds=cornerLon,
attributes={'units': lonunits},
id="longitude")
grid = TransientCurveGrid(lataxis, lonaxis, id=gridid, tempmask=mask)
return grid