View Raw SPL
/*****************************************************************************
*                                                                            *
*   TURBO.SPL  Copyright (C) 2021 DSP Development Corporation                *
*                               All Rights Reserved                          *
*                                                                            *
*   Author:      Randy Race                                                  *
*                                                                            *
*   Synopsis:    Generate a colormap of blue, green, yellow                  *
*                                                                            *
*   Revisions:   30 Mar 2021  RRR  Creation                                  *
*                                                                            *
*****************************************************************************/


#if @HELP_TURBO

    TURBO

    Purpose: Generates a colormap of blue, green, yellow.

    Syntax:  TURBO(len)

               len - optional colormap length, defaults to
                     the length of the current colormap


    Returns: A table of RGB triples suitable for the SETCOLORMAP function.

    Example:
             clen = length(getcolormap());
             density(ravel(rep(0..(clen-1), 32), clen)');
             turbo;

             Creates a table of 32 x colormap length RBG values and
             displays the resulting colors. The resulting image is a
             vertical plot of colors ranging from blue (lowest) to
             green to yellow (highest).

    Example:
             turbo(256);showcmap

             Creates a table of 32 x 256 length RBG values and
             displays the resulting colors. The resulting image is a
             vertical plot of colors ranging from blue (lowest) to
             green to yellow (highest).

    Remarks:
             TURBO() by itself sets the colormap and shading.

             a = turbo() or setcolormap(turbo()) returns the rgb values.
             In this case, use SETSHADING to make the new colormap
             take effect on an existing density or 2D plot.

             The colormap is very similar to RAINBOW, but is meant to
             provide better color separation for viewers with some forms
             of color blindness.

    See Also:
             Autumn
             Bone
             Cool
             Copper
             Gray
             Hot
             Hsv
             Pink
             Rainbow
             Setcolormap
             Setshading
             Showcmap
             Spring
             Summer
             Winter
#endif


/* turbo colormap */
turbo(cmaplen)
{
        local rgb, rgblen;

        if (argc < 1)
        {
                cmaplen = length(getcolormap());
        }

        /* RGB colors */
        rgb =
        {
                { 0.18995, 0.07176, 0.23217 },
                { 0.19483, 0.08339, 0.26149 },
                { 0.19956, 0.09498, 0.29024 },
                { 0.20415, 0.10652, 0.31844 },
                { 0.20860, 0.11802, 0.34607 },
                { 0.21291, 0.12947, 0.37314 },
                { 0.21708, 0.14087, 0.39964 },
                { 0.22111, 0.15223, 0.42558 },
                { 0.22500, 0.16354, 0.45096 },
                { 0.22875, 0.17481, 0.47578 },
                { 0.23236, 0.18603, 0.50004 },
                { 0.23582, 0.19720, 0.52373 },
                { 0.23915, 0.20833, 0.54686 },
                { 0.24234, 0.21941, 0.56942 },
                { 0.24539, 0.23044, 0.59142 },
                { 0.24830, 0.24143, 0.61286 },
                { 0.25107, 0.25237, 0.63374 },
                { 0.25369, 0.26327, 0.65406 },
                { 0.25618, 0.27412, 0.67381 },
                { 0.25853, 0.28492, 0.69300 },
                { 0.26074, 0.29568, 0.71162 },
                { 0.26280, 0.30639, 0.72968 },
                { 0.26473, 0.31706, 0.74718 },
                { 0.26652, 0.32768, 0.76412 },
                { 0.26816, 0.33825, 0.78050 },
                { 0.26967, 0.34878, 0.79631 },
                { 0.27103, 0.35926, 0.81156 },
                { 0.27226, 0.36970, 0.82624 },
                { 0.27334, 0.38008, 0.84037 },
                { 0.27429, 0.39043, 0.85393 },
                { 0.27509, 0.40072, 0.86692 },
                { 0.27576, 0.41097, 0.87936 },
                { 0.27628, 0.42118, 0.89123 },
                { 0.27667, 0.43134, 0.90254 },
                { 0.27691, 0.44145, 0.91328 },
                { 0.27701, 0.45152, 0.92347 },
                { 0.27698, 0.46153, 0.93309 },
                { 0.27680, 0.47151, 0.94214 },
                { 0.27648, 0.48144, 0.95064 },
                { 0.27603, 0.49132, 0.95857 },
                { 0.27543, 0.50115, 0.96594 },
                { 0.27469, 0.51094, 0.97275 },
                { 0.27381, 0.52069, 0.97899 },
                { 0.27273, 0.53040, 0.98461 },
                { 0.27106, 0.54015, 0.98930 },
                { 0.26878, 0.54995, 0.99303 },
                { 0.26592, 0.55979, 0.99583 },
                { 0.26252, 0.56967, 0.99773 },
                { 0.25862, 0.57958, 0.99876 },
                { 0.25425, 0.58950, 0.99896 },
                { 0.24946, 0.59943, 0.99835 },
                { 0.24427, 0.60937, 0.99697 },
                { 0.23874, 0.61931, 0.99485 },
                { 0.23288, 0.62923, 0.99202 },
                { 0.22676, 0.63913, 0.98851 },
                { 0.22039, 0.64901, 0.98436 },
                { 0.21382, 0.65886, 0.97959 },
                { 0.20708, 0.66866, 0.97423 },
                { 0.20021, 0.67842, 0.96833 },
                { 0.19326, 0.68812, 0.96190 },
                { 0.18625, 0.69775, 0.95498 },
                { 0.17923, 0.70732, 0.94761 },
                { 0.17223, 0.71680, 0.93981 },
                { 0.16529, 0.72620, 0.93161 },
                { 0.15844, 0.73551, 0.92305 },
                { 0.15173, 0.74472, 0.91416 },
                { 0.14519, 0.75381, 0.90496 },
                { 0.13886, 0.76279, 0.89550 },
                { 0.13278, 0.77165, 0.88580 },
                { 0.12698, 0.78037, 0.87590 },
                { 0.12151, 0.78896, 0.86581 },
                { 0.11639, 0.79740, 0.85559 },
                { 0.11167, 0.80569, 0.84525 },
                { 0.10738, 0.81381, 0.83484 },
                { 0.10357, 0.82177, 0.82437 },
                { 0.10026, 0.82955, 0.81389 },
                { 0.09750, 0.83714, 0.80342 },
                { 0.09532, 0.84455, 0.79299 },
                { 0.09377, 0.85175, 0.78264 },
                { 0.09287, 0.85875, 0.77240 },
                { 0.09267, 0.86554, 0.76230 },
                { 0.09320, 0.87211, 0.75237 },
                { 0.09451, 0.87844, 0.74265 },
                { 0.09662, 0.88454, 0.73316 },
                { 0.09958, 0.89040, 0.72393 },
                { 0.10342, 0.89600, 0.71500 },
                { 0.10815, 0.90142, 0.70599 },
                { 0.11374, 0.90673, 0.69651 },
                { 0.12014, 0.91193, 0.68660 },
                { 0.12733, 0.91701, 0.67627 },
                { 0.13526, 0.92197, 0.66556 },
                { 0.14391, 0.92680, 0.65448 },
                { 0.15323, 0.93151, 0.64308 },
                { 0.16319, 0.93609, 0.63137 },
                { 0.17377, 0.94053, 0.61938 },
                { 0.18491, 0.94484, 0.60713 },
                { 0.19659, 0.94901, 0.59466 },
                { 0.20877, 0.95304, 0.58199 },
                { 0.22142, 0.95692, 0.56914 },
                { 0.23449, 0.96065, 0.55614 },
                { 0.24797, 0.96423, 0.54303 },
                { 0.26180, 0.96765, 0.52981 },
                { 0.27597, 0.97092, 0.51653 },
                { 0.29042, 0.97403, 0.50321 },
                { 0.30513, 0.97697, 0.48987 },
                { 0.32006, 0.97974, 0.47654 },
                { 0.33517, 0.98234, 0.46325 },
                { 0.35043, 0.98477, 0.45002 },
                { 0.36581, 0.98702, 0.43688 },
                { 0.38127, 0.98909, 0.42386 },
                { 0.39678, 0.99098, 0.41098 },
                { 0.41229, 0.99268, 0.39826 },
                { 0.42778, 0.99419, 0.38575 },
                { 0.44321, 0.99551, 0.37345 },
                { 0.45854, 0.99663, 0.36140 },
                { 0.47375, 0.99755, 0.34963 },
                { 0.48879, 0.99828, 0.33816 },
                { 0.50362, 0.99879, 0.32701 },
                { 0.51822, 0.99910, 0.31622 },
                { 0.53255, 0.99919, 0.30581 },
                { 0.54658, 0.99907, 0.29581 },
                { 0.56026, 0.99873, 0.28623 },
                { 0.57357, 0.99817, 0.27712 },
                { 0.58646, 0.99739, 0.26849 },
                { 0.59891, 0.99638, 0.26038 },
                { 0.61088, 0.99514, 0.25280 },
                { 0.62233, 0.99366, 0.24579 },
                { 0.63323, 0.99195, 0.23937 },
                { 0.64362, 0.98999, 0.23356 },
                { 0.65394, 0.98775, 0.22835 },
                { 0.66428, 0.98524, 0.22370 },
                { 0.67462, 0.98246, 0.21960 },
                { 0.68494, 0.97941, 0.21602 },
                { 0.69525, 0.97610, 0.21294 },
                { 0.70553, 0.97255, 0.21032 },
                { 0.71577, 0.96875, 0.20815 },
                { 0.72596, 0.96470, 0.20640 },
                { 0.73610, 0.96043, 0.20504 },
                { 0.74617, 0.95593, 0.20406 },
                { 0.75617, 0.95121, 0.20343 },
                { 0.76608, 0.94627, 0.20311 },
                { 0.77591, 0.94113, 0.20310 },
                { 0.78563, 0.93579, 0.20336 },
                { 0.79524, 0.93025, 0.20386 },
                { 0.80473, 0.92452, 0.20459 },
                { 0.81410, 0.91861, 0.20552 },
                { 0.82333, 0.91253, 0.20663 },
                { 0.83241, 0.90627, 0.20788 },
                { 0.84133, 0.89986, 0.20926 },
                { 0.85010, 0.89328, 0.21074 },
                { 0.85868, 0.88655, 0.21230 },
                { 0.86709, 0.87968, 0.21391 },
                { 0.87530, 0.87267, 0.21555 },
                { 0.88331, 0.86553, 0.21719 },
                { 0.89112, 0.85826, 0.21880 },
                { 0.89870, 0.85087, 0.22038 },
                { 0.90605, 0.84337, 0.22188 },
                { 0.91317, 0.83576, 0.22328 },
                { 0.92004, 0.82806, 0.22456 },
                { 0.92666, 0.82025, 0.22570 },
                { 0.93301, 0.81236, 0.22667 },
                { 0.93909, 0.80439, 0.22744 },
                { 0.94489, 0.79634, 0.22800 },
                { 0.95039, 0.78823, 0.22831 },
                { 0.95560, 0.78005, 0.22836 },
                { 0.96049, 0.77181, 0.22811 },
                { 0.96507, 0.76352, 0.22754 },
                { 0.96931, 0.75519, 0.22663 },
                { 0.97323, 0.74682, 0.22536 },
                { 0.97679, 0.73842, 0.22369 },
                { 0.98000, 0.73000, 0.22161 },
                { 0.98289, 0.72140, 0.21918 },
                { 0.98549, 0.71250, 0.21650 },
                { 0.98781, 0.70330, 0.21358 },
                { 0.98986, 0.69382, 0.21043 },
                { 0.99163, 0.68408, 0.20706 },
                { 0.99314, 0.67408, 0.20348 },
                { 0.99438, 0.66386, 0.19971 },
                { 0.99535, 0.65341, 0.19577 },
                { 0.99607, 0.64277, 0.19165 },
                { 0.99654, 0.63193, 0.18738 },
                { 0.99675, 0.62093, 0.18297 },
                { 0.99672, 0.60977, 0.17842 },
                { 0.99644, 0.59846, 0.17376 },
                { 0.99593, 0.58703, 0.16899 },
                { 0.99517, 0.57549, 0.16412 },
                { 0.99419, 0.56386, 0.15918 },
                { 0.99297, 0.55214, 0.15417 },
                { 0.99153, 0.54036, 0.14910 },
                { 0.98987, 0.52854, 0.14398 },
                { 0.98799, 0.51667, 0.13883 },
                { 0.98590, 0.50479, 0.13367 },
                { 0.98360, 0.49291, 0.12849 },
                { 0.98108, 0.48104, 0.12332 },
                { 0.97837, 0.46920, 0.11817 },
                { 0.97545, 0.45740, 0.11305 },
                { 0.97234, 0.44565, 0.10797 },
                { 0.96904, 0.43399, 0.10294 },
                { 0.96555, 0.42241, 0.09798 },
                { 0.96187, 0.41093, 0.09310 },
                { 0.95801, 0.39958, 0.08831 },
                { 0.95398, 0.38836, 0.08362 },
                { 0.94977, 0.37729, 0.07905 },
                { 0.94538, 0.36638, 0.07461 },
                { 0.94084, 0.35566, 0.07031 },
                { 0.93612, 0.34513, 0.06616 },
                { 0.93125, 0.33482, 0.06218 },
                { 0.92623, 0.32473, 0.05837 },
                { 0.92105, 0.31489, 0.05475 },
                { 0.91572, 0.30530, 0.05134 },
                { 0.91024, 0.29599, 0.04814 },
                { 0.90463, 0.28696, 0.04516 },
                { 0.89888, 0.27824, 0.04243 },
                { 0.89298, 0.26981, 0.03993 },
                { 0.88691, 0.26152, 0.03753 },
                { 0.88066, 0.25334, 0.03521 },
                { 0.87422, 0.24526, 0.03297 },
                { 0.86760, 0.23730, 0.03082 },
                { 0.86079, 0.22945, 0.02875 },
                { 0.85380, 0.22170, 0.02677 },
                { 0.84662, 0.21407, 0.02487 },
                { 0.83926, 0.20654, 0.02305 },
                { 0.83172, 0.19912, 0.02131 },
                { 0.82399, 0.19182, 0.01966 },
                { 0.81608, 0.18462, 0.01809 },
                { 0.80799, 0.17753, 0.01660 },
                { 0.79971, 0.17055, 0.01520 },
                { 0.79125, 0.16368, 0.01387 },
                { 0.78260, 0.15693, 0.01264 },
                { 0.77377, 0.15028, 0.01148 },
                { 0.76476, 0.14374, 0.01041 },
                { 0.75556, 0.13731, 0.00942 },
                { 0.74617, 0.13098, 0.00851 },
                { 0.73661, 0.12477, 0.00769 },
                { 0.72686, 0.11867, 0.00695 },
                { 0.71692, 0.11268, 0.00629 },
                { 0.70680, 0.10680, 0.00571 },
                { 0.69650, 0.10102, 0.00522 },
                { 0.68602, 0.09536, 0.00481 },
                { 0.67535, 0.08980, 0.00449 },
                { 0.66449, 0.08436, 0.00424 },
                { 0.65345, 0.07902, 0.00408 },
                { 0.64223, 0.07380, 0.00401 },
                { 0.63082, 0.06868, 0.00401 },
                { 0.61923, 0.06367, 0.00410 },
                { 0.60746, 0.05878, 0.00427 },
                { 0.59550, 0.05399, 0.00453 },
                { 0.58336, 0.04931, 0.00486 },
                { 0.57103, 0.04474, 0.00529 },
                { 0.55852, 0.04028, 0.00579 },
                { 0.54583, 0.03593, 0.00638 },
                { 0.53295, 0.03169, 0.00705 },
                { 0.51989, 0.02756, 0.00780 },
                { 0.50664, 0.02354, 0.00863 },
                { 0.49321, 0.01963, 0.00955 },
                { 0.47960, 0.01583, 0.01055 }
        };

        if ((rgblen = length(rgb)) != cmaplen)
        {
                /* interpolate to colormap size */
                rgb = xylookup(1..length(rgb), rgb, linspace(1, length(rgb), cmaplen));

                /* remove X columns */
                rgb = rgb[.., 1..2..6];
        }

        if (outargc == 0)
        {
                /* set the colormap and shading */
                setplotshading(rgb);
        }
        else
        {
                /* return the colormap */
                setrgbprops(rgb);

                return(rgb);
        }
}