cpc.geofiles.conversion Module

Contains methods for converting between different file formats

Functions

fcst_bin_to_txt(bin_file, grid, fcst_ptiles, desired_output_thresholds, txt_file, output_threshold_type=’ptile’, terciles=False, output_grid=None)

Converts a forecast binary file to a text file

The forecast binary file must contain probabilities of exceeding certain percentiles (AKA a POE file), where the percentiles are ascending in the file. The dimensions of the file should be (P x L), where:

• P is the percentile
• L is the location

If output_threshold_type is set to ‘ptile’ (‘raw’), then the probability of exceeding the given ptiles (raw values) will be written to the output file under the headers ptileXX, ptileYY (rawvalXX, rawvalYY), etc.

If terciles=True, then headers will be different (see the Parameters section below)

Parameters

• bin_file (string)
  • Binary file containing the forecast, with the dimensions (ptile x Y x X)
• grid (Grid)
  • Grid that the binary file maps to
• fcst_ptiles (list)
  • 1-dimensional list of ptiles found in the forecast file
• desired_output_thresholds (list)
  • 1-dimensional list of ptiles or raw values to include in the output file
• txt_file (string)
  • Text file to write data to (will be overwritten)
• output_threshold_type (string, optional)
  • Type of thresholds to write out (‘ptile’ or ‘raw’)
• terciles (bool, optional)
  • If True, will output tercile probabilities (with headers below, normal , and above)
  • If False (default), will output probabilities of exceeding percentiles (with headers ptileXX, ptileYY, etc.)
  • Can only be set when 2 percentiles are supplied
• output_grid (Grid, optional))
  • data_utils.gridded.grid to interpolate to before converting to a txt file

Raises

• ValueError
  • If arguments are incorrect

obs_bin_to_txt(bin_file, grid, desired_output_thresholds, txt_file, output_threshold_type=’ptile’, climo_file=None, climo_ptiles=None, output_grid=None)

Converts an observation binary file to a text file

The observation binary file must contain raw values of the given variable. The file should be a single dimension (locations).

A climatology file is necessary if output_threshold_type=’ptile’, in which case the raw values in the observation file needs to first be converted to ptiles. The climatology file must have probabilities of exceeding a given set of percentiles, and be of dimensions (P x L) where:

• P is the percentile
• L is the location

climo_ptiles must also be provided specifying the percentiles in the file.

Parameters

• bin_file (string)
  • Binary file containing the observation, with the dimensions (Y x X)
• grid (Grid)
  • data_utils.gridded.grid.Grid that the binary file maps to
• desired_output_thresholds (array_like)
  • 1-dimensional list of thresholds (either ptiles or raw values) to include in the output file
• txt_file (string)
  • Text file to write data to (will be overwritten)
• output_threshold_type (string, optional)
  • Type of thresholds to write out (‘ptile’ or ‘raw’)
• climo_file (string, optional)
  • Binary file containing the climatology (needed to convert raw observations to a category), with the dimensions (Y x X)
• climo_ptiles (array_like, optional)
  • List of percentiles found in the climatology file
• output_grid (Grid, optional)
  • data_utils.gridded.grid.Grid to interpolate to before converting to a txt file

Raises

• ValueError
  • If arguments are incorrect