1.2.3 Output data

There are 6 general categories of output produced by GMT:

1. PostScript plot commands.

2. Data Table(s).

3. Gridded data set(s).

4. Statistics & Summaries.

5. Warnings and Errors, written to stderr.

6. Exit status (0 means success, otherwise failure).

Note: GMT automatically creates and updates a history of past GMT command options for the common switches. This history file is called .gmtcommands and one will be created in every directory from which GMT programs are executed. Many initial problems with GMT usage result from not fully appreciating the relationships shown in Figure 1.1.