The stplot package includes general purpose plotting tasks tailored toward STSDAS data formats; that is, tables and group format image files. These tasks include:

sgraph

The sgraph task includes all of the functions of the IRAF plot.graph task, but adds the ability to plot from STSDAS tables (images and text files were supported by graph). In sgraph, you can plot a single column against a row, or a column against another column.

depind

The depind task prints pairs of dependent and independent pixel values from two one-dimensional images to STDOUT. This may be piped to sgraph or plot.graph to plot one image line (spectrum) against another.

skymap

The skymap task interprets an STSDAS table as a catalog of coordinates and brightnesses to produce a star chart. That is, it plots symbols whose size depends on brightness and whose position on the plot is a projection of the celestial coordinates. There is an interactive interface that allows a user to roam among different parts of the catalog, change the chart scale, and perform other actions.

Group Format

Three tasks support group format STSDAS images and plot more than one group member on a single graph.

grlist

A generic task to permit converting a range of groups to a list of image names. The output list may be used by any task that accepts alist of images as input.

grplot

Overplots selected members on a single plot

grspec

Uses the noao.onedspec.specplot task to allow interaction with a plot of several group members.

fieldplot

The fieldplot task is a general purpose task to draw arrows representing a vector field, that is, directions and magnitudes. Data are read from STDIN to represent the coordinates of a point and the field vector. The vector may be either a pair of projected magnitudes or the absolute magnitude and direction. The magnitude may be scaled arbitrarily.

igi

The igi task is an interactive interpreter for producing arbitrary plots. The syntax of the commands is based on Mongo, but igi operates within IRAF and is device independent. (A complete reference manual for igi is available on request from the STSDAS group.)

newcont

The newcont task is an improved version of plot.contour. The algorithm used produces smoother contours that will not cross. It also provides more options for determining contour level and specifying contour line types.

rdsiaf

The rdsiaf task reads in the aperture descriptions from the Project Data Base (PDB) Science Instrument Aperture File (SIAF) and writes them into an SDAS table. This table is used by siaper, which plots the telescope apertures.

siaper

The siaper task uses any graphics device to draw the science instrument apertures of the HST. It requires an input image containing WCS information. The drawn aperture can then be laid over an image.

psikern

The psikern task is a GIO kernel that translates from IRAF's graphics to PostScript.