PC-PLOT is a program that allows you to compose scientific linear-linear, semi-log, or log-log plots on the screen. Multiple captions and sets of data may be added, modified, or deleted at will. Additionally, functions and arrows can also be added to the graph. Once the screen plot is in the form you desire, the entire plot can be sent to an HP-compatible plotter or to a disk file for later plotting. The plot can also be saved in a file for later recall and modification. With the shareware program PRINTGL (Ravitz Software Inc., PO Box 25068, Lexington KY 40524-5068) the plot can also be printed on almost any printer or saved as a PostScript or bitmapped PCX file.

Data may be read from data files or entered from the keyboard. Keyboard entered data may also be saved in a disk file for subsequent incorporation into other plots. The data can then be plotted (1) as discrete points using any keyboard symbol or 10 special plotter symbols, (2) as a series of straight lines joining the data points, (3) as a natural cubic-spline fit curve passing through the data points, (4) as a B-spline fit to the data, (5) as an m-th degree polynomial obtained by a least-squares fit to the data, or (6) as a histogram. Seven different line styles are available and eight different pen widths (colors) may be used. Captions or legends for the graph can be entered only from the keyboard; however, any caption (like any data set) can be erased or modified and rewritten on the graph until its location is exactly where you want it. Captions and labels can have subscripts, superscripts, and Greek letters.

PC-PLOT is entirely menu driven with most menu items being self explanatory, although help screens are available. The basic operation of the program is straightforward. First the size, axis types, and labels for the graph are defined and then set(s) of data and captions are added. Finally, the graph is plotted (or saved for later recall). Each step in the creation (or modification) of a graph is controlled by a program menu. While the purpose of most menu items require little explanation, there are some items which allow responses not described on the menus or help screens. The manual distributed with PC-PLOT describes the various program options and gives details and hints about the use of this program. Here is an example plot showing some of the features built into PC-PLOT.