TOVS Path-P IDL Tools Tutorial

Introduction  |   Getting Started  |   Tutorial:  1  2  3  4  |   Example:  1  2  3  4  |   Extended Help

Tutorial 4: Extracting, saving, and restoring 3-D time-series

This section of the tutorial explains various methods for extracting 3-D time-series of data from the HDF files and explains how to save and restore these data for future analysis. You will learn how to use the following IDL routines:

PPP_EXTRACT - Extracting a 3-D slice of data and associated metadata from the HDF files

You can use PPP_EXTRACT to read a 3-D slice of TOVS Path-P data for a given SDS and range of dates. PPP_EXTRACT is a function with two required arguments: a named variable which will be returned with the extracted data and the sds_name to extract. Like PPP_STATS, PPP_ANIMATE, and PPP_PLOT, it accepts the DATES keyword or a range of dates bounded by START_DATE and END_DATE. It also accepts keywords for two additional portions of metadata from the HDF files: LABELS designates a named variable that will be returned with a string array of dates for each layer of the 3-D data and SDS_INFO designates a named variable that will be returned with a structure containing the SDS metadata. For an example, see the TOVS Path-P PPP_EXTRACT Example

Please refer to the Extended Help Documentation for details on the other keywords to PPP_EXTRACT.

PPP_SAVE and PPP_RESTORE - Saving and restoring a 3-D slice and metadata to/from an external file

You can use PPP_SAVE and PPP_RESTORE to write/restore the data and metadata from PPP_EXTRACT to/from an external file for use in other IDL sessions. Both routines have four required arguments: the data array, the SDS_INFO structure, a string array of date labels (one for each date layer in the data array), and the name of the external file. For an example, see the TOVS Path-P PPP_SAVE and PPP_RESTORE Example


Please refer to the Extended Help Documentation for details on using PPP_SAVE and PPP_RESTORE.