ASCII2NC: Using Python Embedding

met_tool_wrapper/ASCII2NC/ASCII2NC_python _embedding.conf

Scientific Objective

Simply converting file formats so point observations can be read by the MET tools through the use of a Python script

Datasets

Observations: Precipitation accumulation observations in ASCII text files

Location: All of the input data required for this use case can be found in the met_test sample data tarball. Click here to the METplus releases page and download sample data for the appropriate release: https://github.com/dtcenter/METplus/releases

This tarball should be unpacked into the directory that you will set the value of INPUT_BASE. See Running METplus section for more information.

Data Source: Unknown

METplus Components

This use case utilizes the METplus ASCII2NC wrapper to generate a command to run the MET tool ASCII2NC.

METplus Workflow

ASCII2NC is the only tool called in this example. It has one run time, but the time is not relevant because the files processed do not have any time information in the names.

METplus Configuration

METplus first loads all of the configuration files found in parm/metplus_config, then it loads any configuration files passed to METplus via the command line with the -c option, i.e. -c parm/use_cases/met_tool_wrapper/ASCII2NC/ASCII2NC_python_embedding.conf

[config]

# Documentation for this use case can be found at
# https://metplus.readthedocs.io/en/latest/generated/met_tool_wrapper/ASCII2NC/ASCII2NC_python_embedding.html

# For additional information, please see the METplus Users Guide.
# https://metplus.readthedocs.io/en/latest/Users_Guide

###
# Processes to run
# https://metplus.readthedocs.io/en/latest/Users_Guide/systemconfiguration.html#process-list
###

PROCESS_LIST = ASCII2NC


###
# Time Info
# LOOP_BY options are INIT, VALID, RETRO, and REALTIME
# If set to INIT or RETRO:
#   INIT_TIME_FMT, INIT_BEG, INIT_END, and INIT_INCREMENT must also be set
# If set to VALID or REALTIME:
#   VALID_TIME_FMT, VALID_BEG, VALID_END, and VALID_INCREMENT must also be set
# LEAD_SEQ is the list of forecast leads to process
# https://metplus.readthedocs.io/en/latest/Users_Guide/systemconfiguration.html#timing-control
###

LOOP_BY = VALID
VALID_TIME_FMT = %Y%m%d%H
VALID_BEG = 2010010112
VALID_END = 2010010112
VALID_INCREMENT = 1M

LEAD_SEQ = 0


###
# File I/O
# https://metplus.readthedocs.io/en/latest/Users_Guide/systemconfiguration.html#directory-and-filename-template-info
###

ASCII2NC_INPUT_DIR =
ASCII2NC_INPUT_TEMPLATE = "{MET_INSTALL_DIR}/share/met/python/examples/read_ascii_point.py {INPUT_BASE}/met_test/data/sample_obs/ascii/sample_ascii_obs.txt"

ASCII2NC_OUTPUT_DIR =
ASCII2NC_OUTPUT_TEMPLATE = {OUTPUT_BASE}/met_tool_wrapper/ASCII2NC/ascii2nc_python.nc

ASCII2NC_SKIP_IF_OUTPUT_EXISTS = False

ASCII2NC_FILE_WINDOW_BEGIN = 0
ASCII2NC_FILE_WINDOW_END = 0


###
# ASCII2NC Settings
# https://metplus.readthedocs.io/en/latest/Users_Guide/wrappers.html#ascii2nc
###

#LOG_ASCII2NC_VERBOSITY = 1
#ASCII2NC_CONFIG_FILE =

ASCII2NC_WINDOW_BEGIN = 0
ASCII2NC_WINDOW_END = 0

ASCII2NC_INPUT_FORMAT = python

ASCII2NC_MASK_GRID =
ASCII2NC_MASK_POLY =
ASCII2NC_MASK_SID =

ASCII2NC_TIME_SUMMARY_FLAG = False
ASCII2NC_TIME_SUMMARY_RAW_DATA = False
ASCII2NC_TIME_SUMMARY_BEG = 000000
ASCII2NC_TIME_SUMMARY_END = 235959
ASCII2NC_TIME_SUMMARY_STEP = 300
ASCII2NC_TIME_SUMMARY_WIDTH = 600
ASCII2NC_TIME_SUMMARY_GRIB_CODES = 11, 204, 211
ASCII2NC_TIME_SUMMARY_VAR_NAMES =
ASCII2NC_TIME_SUMMARY_TYPES = min, max, range, mean, stdev, median, p80
ASCII2NC_TIME_SUMMARY_VALID_FREQ = 0
ASCII2NC_TIME_SUMMARY_VALID_THRESH = 0.0

MET Configuration

None. No MET configuration file for ASCII2NC is used in this case.

Python Embedding

This use case calls a Python script to read the input data. The Python script is stored in the MET repository: /path/to/MET/installation/share/met/python/read_ascii_point.py

read_ascii_point.py

Running METplus

This use case can be run two ways:

1. Passing in ASCII2NC_python_embedding.conf then a user-specific system configuration file:

   run_metplus.py -c /path/to/METplus/parm/use_cases/met_tool_wrapper/ASCII2NC/ASCII2NC_python_embedding.conf -c /path/to/user_system.conf
   

2. Modifying the configurations in parm/metplus_config, then passing in ASCII2NC_python_embedding.conf:

   run_metplus.py -c /path/to/METplus/parm/use_cases/met_tool_wrapper/ASCII2NC/ASCII2NC_python_embedding.conf
   

The former method is recommended. Whether you add them to a user-specific configuration file or modify the metplus_config files, the following variables must be set correctly:

• INPUT_BASE - Path to directory where sample data tarballs are unpacked (See Datasets section to obtain tarballs). This is not required to run METplus, but it is required to run the examples in parm/use_cases

• OUTPUT_BASE - Path where METplus output will be written. This must be in a location where you have write permissions

• MET_INSTALL_DIR - Path to location where MET is installed locally

Example User Configuration File:

[dir]
INPUT_BASE = /path/to/sample/input/data
OUTPUT_BASE = /path/to/output/dir
MET_INSTALL_DIR = /path/to/met-X.Y

NOTE: All of these items must be found under the [dir] section.

Expected Output

A successful run will output the following both to the screen and to the logfile:

INFO: METplus has successfully finished running.

Refer to the value set for OUTPUT_BASE to find where the output data was generated. Output for this use case will be found in met_tool_wrapper/ASCII2NC (relative to OUTPUT_BASE) and will contain the following file:

• ascii2nc_python.nc

Keywords

Note

• ASCII2NCToolUseCase

• PythonEmbeddingFileUseCase

Navigate to the METplus Quick Search for Use Cases page to discover other similar use cases.

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