#### GNUPLOT RGB FORMULAE ########################################
# List of palette functions in Gnuplot (show palette rgbformulae).
# Note that "180x" corresponds to pi*x etc. since built-in trig
# functions use radians.
#   00: 0              01: 0.5            02: 1
#   03: x              04: x^2            05: x^3
#   06: x^4            07: sqrt(x)        08: sqrt(sqrt(x))
#   09: sin(90x)       10: cos(90x)       11: |x-0.5|
#   12: (2x-1)^2       13: sin(180x)      14: |cos(180x)|
#   15: sin(360x)      16: cos(360x)      17: |sin(360x)|
#   18: |cos(360x)|    19: |sin(720x)|    20: |cos(720x)|
#   21: 3x             22: 3x-1           23: 3x-2
#   24: |3x-1|         25: |3x-2|         26: (3x-1)/2
#   27: (3x-2)/2       28: |(3x-1)/2|     29: |(3x-2)/2|
#   30: x/0.32-0.78125 31: 2*x-0.84       32: 4x;1;-2x+1.84;x/0.08-11.5
#   33: |2*x - 0.5|    34: 2*x            35: 2*x - 0.5
#   36: 2*x - 1
# * negative numbers mean inverted=negative colour component
# * thus the ranges in `set pm3d rgbformulae' are -36..36
# Some nice schemes in RGB color space
# 07,05,15 ... traditional pm3d (black-blue-red-yellow)
# 03,11,06 ... green-red-violet
# 23,28,03 ... ocean (green-blue-white); try also all other permutations
# 21,22,23 ... hot (black-red-yellow-white)
# 30,31,32 ... color printable on gray (black-blue-violet-yellow-white)
# 33,13,10 ... rainbow (blue-green-yellow-red)
# 34,35,36 ... AFM hot (black-red-yellow-white)
frgb00(x)=0.
frgb01(x)=0.5
frgb02(x)=1.
frgb03(x)=x
frgb04(x)=x*x
frgb05(x)=x**3
frgb06(x)=x**4
frgb07(x)=sqrt(x)
frgb08(x)=sqrt(sqrt(x))
frgb09(x)=sin(0.5*pi*x)
frgb10(x)=cos(0.5*pi*x)
frgb11(x)=abs(x-0.5)
frgb12(x)=(2.*x-1.)**2
frgb13(x)=sin(pi*x)
frgb14(x)=abs(cos(pi*x))
frgb15(x)=sin(2.*pi*x)
frgb16(x)=cos(2.*pi*x)
frgb17(x)=abs(sin(2.*pi*x))
frgb18(x)=abs(cos(2.*pi*x))
frgb19(x)=abs(sin(4.*pi*x))
frgb20(x)=abs(cos(4.*pi*x))
frgb21(x)=3.*x
frgb22(x)=3.*x-1.
frgb23(x)=3.*x-2.
frgb24(x)=abs(3.*x-1.)
frgb25(x)=abs(3.*x-2.)
frgb26(x)=(3.*x-1.)/2.
frgb27(x)=(3.*x-2.)/2.
frgb28(x)=abs(3.*x-1.)/2.
frgb29(x)=abs(3.*x-2.)/2.
frgb30(x)=x/0.32-0.78125
frgb31(x)=2.*x-0.84
frgb32(x)=x<0.25 ? 4.*x : x<0.42 ? 1 : x<0.92 ?-2.*x+1.84:x/0.08-11.5
frgb33(x)=abs(2.*x-0.5)
frgb34(x)=2.*x
frgb35(x)=2.*x-0.5
frgb36(x)=2.*x-1.