1 p = 30

     2 e(x) = 10.0**((log10(x)*20-p)/10)

     3 f(x) = (x-e(x) < 0)?0:(x-e(x))

     4 d(x,y) = abs(x-f(y))

     5 

     6 set ticslevel 0

     7 set contour

     8 set cntrparam bspline

     9 set cntrparam points 10

    10 set cntrparam order 10

    11 set cntrparam levels incremental 0,5,100

    12 set nosurface

    13 set term table

    14 set out 'data.out'

    15 splot [1:1000] [1:1000] d(x,y)

    16 set out

    17 set term X11

    18 set data style lines

    19 plot 'data.out' index 0 t "100", \

    20         'data.out' index 3 notitle, \

    21         'data.out' index 6 t "70", \

    22         'data.out' index 9 notitle, \

    23         'data.out' index 12 t "60", \

    24         'data.out' index 15 notitle, \

    25         'data.out' index 18 t "10"