Data-file

Discrete data contained in a file can displayed by specifying the name of the data file (enclosed in quotes) on the plot command line.

Data files should contain one data point per line. A data point may be specified either as an X and Y value separated by blank space, or as just the Y value, in which case the program will use the number of the coordinate as the X value. Coordinate numbers start at 0 and are incremented for each data point read. Lines beginning with # (or ! on VMS) will be treated as comments and ignored. NOTE that blank lines cause a break in the input, and if the plot style is lines or linespoints (see plot style) there will be no line drawn between the preceding and following points. This does not change the plot style, as would plotting the data as separate curves.

This example compares the data in the file population.dat to a theoretical curve:

        pop(x) = 103*exp((1965-x)/10)
        plot [1960:1990] 'population.dat', pop(x)

The file population.dat might contain:

 # Gnu population in Antarctica since 1965
 1965   103
 1970   55
 1975   34
 1980   24
 1985   10