Columnhead

The columnhead(x) function may only be used as part of a plot, splot, or stats command. It evaluates to a string containing the content of column x in the first line of a data file. This is typically used to extract the column header for use in a plot title. See plot datafile using (p. [*]). Example:
    set datafile columnheader
    plot for [i=2:4] DATA using 1:i title columnhead(i)