.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.42) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. 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Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "Gradient 3pm" .TH Gradient 3pm "2022-10-21" "perl v5.34.0" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" Math::Gradient \- Perl extension for calculating gradients for colour transitions, etc. .SH "SYNOPSIS" .IX Header "SYNOPSIS" use Math::Gradient qw(multi_gradient); .PP # make a 100\-point colour palette to smothly transition between 6 \s-1RGB\s0 values .PP my(@hot_spots) = ([ 0, 255, 0 ], [ 255, 255, 0 ], [ 127, 127, 127 ], [ 0, 0, 255 ], [ 127, 0, 0 ], [ 255, 255, 255 ]); .PP my(@gradient) = multi_array_gradient(100, \f(CW@hot_spots\fR); .SH "DESCRIPTION" .IX Header "DESCRIPTION" Math::Gradient is used to calculate smooth transitions between numerical values (also known as a \*(L"Gradient\*(R"). I wrote this module mainly to mix colours, but it probably has several other applications. Methods are supported to handle both basic and multiple-point gradients, both with scalars and arrays. .SH "FUNCTIONS" .IX Header "FUNCTIONS" .ie n .IP "gradient($start_value, $end_value, $steps)" 4 .el .IP "gradient($start_value, \f(CW$end_value\fR, \f(CW$steps\fR)" 4 .IX Item "gradient($start_value, $end_value, $steps)" This function will return an array of evenly distributed values between \f(CW$start_value\fR and \f(CW$end_value\fR. All three values supplied should be numeric. \f(CW$steps\fR should be the number of steps that should occur between the two points; for instance, gradient(0, 10, 4) would return the array (2, 4, 6, 8); the 4 evenly-distributed steps necessary to get from 0 to 10, whereas gradient(0, 1, 3) would return (0.25, 0.5, 0.75). This is the basest function in the Math::Gradient module and isn't very exciting, but all of the other functions below derive their work from it. .ie n .IP "array_gradient($start_value, $end_value, $steps)" 4 .el .IP "array_gradient($start_value, \f(CW$end_value\fR, \f(CW$steps\fR)" 4 .IX Item "array_gradient($start_value, $end_value, $steps)" While \fBgradient()\fR takes numeric values for \f(CW$start_value\fR and \f(CW$end_value\fR, \fBarray_gradient()\fR takes arrayrefs instead. The arrays supplied are expected to be lists of numerical values, and all of the arrays should contain the same number of elements. \fBarray_gradient()\fR will return a list of arrayrefs signifying the gradient of all values on the lists \f(CW$start_value\fR and \f(CW$end_value\fR. .Sp For example, calling array_gradient([ 0, 100, 2 ], [ 100, 50, 70], 3) would return: ([ 25, 87.5, 19 ], [ 50, 75, 36 ], [ 75, 62.5, 53 ]). .ie n .IP "multi_gradient($steps, @values)" 4 .el .IP "multi_gradient($steps, \f(CW@values\fR)" 4 .IX Item "multi_gradient($steps, @values)" \&\fBmulti_gradient()\fR calculates multiple gradients at once, returning one list that is an even transition between all points, with the values supplied interpolated evenly within the list. If \f(CW$steps\fR is less than the number of entries in the list \f(CW@values\fR, items are deleted from \f(CW@values\fR instead. .Sp For example, calling multi_gradient(10, 0, 100, 50) would return: (0, 25, 50, 75, 100, 90, 80, 70, 60, 50) .ie n .IP "multi_array_gradient($steps, @values)" 4 .el .IP "multi_array_gradient($steps, \f(CW@values\fR)" 4 .IX Item "multi_array_gradient($steps, @values)" \&\fBmulti_array_gradient()\fR is the same as multi_gradient, except that it works on arrayrefs instead of scalars (like \fBarray_gradient()\fR is to \fBgradient()\fR). .SH "AUTHOR" .IX Header "AUTHOR" Tyler MacDonald, .SH "COPYRIGHT AND LICENSE" .IX Header "COPYRIGHT AND LICENSE" Copyright 2003 by Tyler MacDonald .PP This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.