If no files are given, psxy will read standard input. Selects the map projection. More details can be found in the psbasemap manpages. No space between the option flag and the associated argu- ments. Sets the preferred positive direction.
Sets map boundary tickmark intervals.
See psbasemap for details. Gray shade or color for filling of positive anomalies. Color range from 0-255 for each of the rgb components. Number of header records can be changed by editing your . gmtdefaults file. If used, GMT default is 1 header record.