    # Example 5 - Contouring ungridded data

    # Data from figure
    # 5 of Koch et al., 1983, J. Climate Appl. Met.,
    # volume 22, pages 1487-1503.
    open example5.dat
    read columns x y z
    close
    set x size 12
    set x axis 0 12 2
    set y size 10
    set y axis 0 10 2
    draw axes
    set line width symbol 0.2
    set symbol size 0.2
    draw symbol bullet
    set font size 8
    draw values
    set x grid 0 12 0.25
    set y grid 0 10 0.25

    # Use default method (Barnes)
    convert columns to grid

    set font size 10
    draw contour 0 40 2
    set font size 12
    draw title "Example 5 -- wind (Fig5 Koch et al, 1983)"