def readImageData(location, varID, tValue, zValue, grid, fillValue):
""" Reads data from this variable, projected on to the given grid.
location = location of dataset (full file path, OPeNDAP URL etc)
varID = unique ID for a variable
tValue = time stamp in ISO8601
zValue = value of ELEVATION parameter
grid = grid onto which data should be projected
fillvalue = value to use for missing data
returns an array of floating-point numbers representing the data,
or None if the variable with id varID does not exist. """
if not grid.isLatLon:
# TODO: relax this limitation:
raise "Can only read data onto grids in lat-lon projections"
try:
return DataReader.read(location, varID, tValue, zValue,
grid.latValues, grid.lonValues, fillValue)
except InvalidDimensionValueException, e:
raise InvalidDimensionValue(e.getDimName(), e.getValue())
def readDataValue(location, varID, tValue, zValue, lat, lon, fillValue):
""" Reads an individual data point for GetFeatureInfo
location = location of dataset (full file path, OPeNDAP URL etc)
varID = unique ID for a variable
tValue = time stamp in ISO8601
zValue = value of ELEVATION parameter
lat, lon = latitude and longitude of the data value
i, j = values used in GetFeatureInfo
returns the value at the given point, or None if there is no data at the point """
try:
# We can re-use the read() method
value = DataReader.read(location, varID, tValue, zValue, [lat], [lon], fillValue)[0]
# If data is missing, read() will return the fill value, having converted
# it from a double to a float
if value == Float(fillValue).floatValue():
return None
else:
return value
except InvalidDimensionValueException, e:
raise InvalidDimensionValue(e.getDimName(), e.getValue())