cpc.geofiles.reading Module

Contains methods for reading gridded data.

Functions

read_grib(file, grib_type, grib_var, grib_level, geogrid, yrev=False, grep_fhr=None, debug=False)

Reads a record from a grib file

Uses wgrib for grib1 files, and wgrib2 for grib2 files. For grib1 files, the record in question is written to a temporary binary file, the data is read in, and the file is removed. wgrib2 has the ability to write the record to STDIN, so no temporary file is necessary to read in a record from a grib2 file.

Parameters

• file (string): name of the grib file to read from
• grib_type (string): type of grib file (‘grib1’, ‘grib2’)
• variable (string): name of the variable in the grib record (ex. TMP, UGRD, etc.)
• level (string): name of the level (ex. ‘2 m above ground’, ‘850 mb’, etc.)
• geogrid (Geogrid): Geogrid the data should be placed on
• yrev (optional): option to flip the data in the y-direction (eg. ECMWF grib files)
• grep_fhr (optional): fhr to grep grib file for - this is useful for gribs that may for some reason have duplicate records for a given variable but with different fhrs. This way you can get the record for the correct fhr.

Returns

• (array_like): a data array containing the appropriate grib record

Raises

• ReadingError: if wgrib has a problem reading the grib and/or writing the temp file
• ReadingError: if no grib record is found