    # Example 12 -- Linegraph with key inside plot

    set font size 10		# points (1in = 72pt)
    set x size 10			# cm
    set y size 10			# cm
    set x name "Height"
    set y name "Total Energy"

    # Following axis setups not necessary; will autoscale if you
    # remove these.
    set x margin 3
    set x axis 800 960 20
    set y margin 3
    set y axis -0.4 1 0.2

    # Read data.  Format is columns (x, y1, y2, y3, y4)
    open example12.dat
    read columns x y
    draw curve
    draw label for last curve "1"

    rewind
    set line width {rpn ..linewidth.. 1.5 *}
    read columns x * y
    draw curve
    draw label for last curve "2"

    rewind
    set line width {rpn ..linewidth.. 1.5 *}
    read columns x * * y
    draw curve
    draw label for last curve "3"

    rewind
    set line width {rpn ..linewidth.. 1.5 *}
    read columns x * * * y
    draw curve
    draw label for last curve "4"

    # Draw the key.
    # NOTES:
    # (1) This key is inside the plot; it's location was chosen
    #     after looking at the data.  To put the key in a different
    #     location, alter the .key_topleft_x. and .key_topleft_y.
    #     variables.  For example, you could put the key to the
    #     right of the plot by changing the next line to:
    #     `.key_topleft_x. = {rpn ..xsize.. 0.5 +}'
    # (2) The variable .dy_inc. is the spacing between lines in
    #     the key.  It should be OK even if you change the
    #     font size above.
    .key_topleft_x. = 0.5		# cm right of left axis
    .key_topleft_y. = 0.5		# cm below top axis
    .dy_inc. = {rpn ..fontsize.. pttocm 1.5 *}

    draw label "1 = Model 1A" at    \
        {rpn ..xleft.. xusertocm .key_topleft_x. +} \
        {rpn ..ytop.. yusertocm .key_topleft_y. -} cm

    .key_topleft_y. += .dy_inc.
    draw label "2 = Model 2A" at    \
        {rpn ..xleft.. xusertocm .key_topleft_x. +} \
        {rpn ..ytop.. yusertocm .key_topleft_y. -} cm

    .key_topleft_y. += .dy_inc.
    draw label "3 = Model 1B" at    \
        {rpn ..xleft.. xusertocm .key_topleft_x. +} \
        {rpn ..ytop.. yusertocm .key_topleft_y. -} cm

    .key_topleft_y. += .dy_inc.
    draw label "4 = Model 2B" at    \
        {rpn ..xleft.. xusertocm .key_topleft_x. +} \
        {rpn ..ytop.. yusertocm .key_topleft_y. -} cm

    draw title "Example 12 -- Total heating vs height of boundary layer"