A text data file for IPW contains a sequence or series of data records. An example would be a temporal data set containing hourly measurements of one or more meteorological parameters at a specific geographic location.
A data record contains one or more data values, which are usually numeric values. Each data value is refered to as a field in the data record.
For example, the IPW command rh2vp accepts a text data file whose data records have two fields: air temperature (in Celsius) and relative humidity (as a decimal fraction between 0 and 1.0):
20.4 0.3 25.1 0.25 16.9 0.78 ...Format
The format of a text data file is somewhat flexible. The fields of each data record are separated by one or more whitespace characters (spaces and tabs).
It is recommended that each data record should be on a separate line in the file. Specifically, all the fields of a data record should be on a single line in the file, and a line in the data file should contain the fields of just one data record.
Although many IPW commands will accept text data files containing a data record with its fields on different lines as well as data files containing a line with more than one data record, a few commands require one data record per line. Therefore, the one-record-per-line format is recommended for compatibility and consistency across all IPW commands.
This format also makes it easier for a user to visually examine a data text file. Furthermore, the user can utilize the UNIX commands "cut" and "paste" in the preparation and processing of text data files.