Math::GSL::Interp - Interpolation
use Math::GSL::Interp qw/:all/;
my $x_array = [ 0.0, 1.0, 2.0, 3.0, 4.0 ];
# check that we get the last interval if x == last value
$index_result = gsl_interp_bsearch($x_array, 4.0, 0, 4);
print "The last interval is $index_result \n";
- "gsl_interp_accel_alloc()"
- This function returns a pointer to an accelerator object, which is a kind
of iterator for interpolation lookups. It tracks the state of lookups,
thus allowing for application of various acceleration strategies.
- "gsl_interp_accel_find($a, $x_array, $size, $x)"
- This function performs a lookup action on the data array
$x_array of size $size,
using the given accelerator $a. This is how
lookups are performed during evaluation of an interpolation. The function
returns an index i such that $x_array[i] <=
$x <
$x_array[i+1].
- "gsl_interp_accel_reset"
- "gsl_interp_accel_free($a)"
- This function frees the accelerator object
$a.
- "gsl_interp_alloc($T, $alloc)"
- This function returns a newly allocated interpolation object of type
$T for $size data-points.
$T must be one of the constants below.
- "gsl_interp_init($interp, $xa, $ya, $size)"
- This function initializes the interpolation object interp for the data
(xa,ya) where xa and ya are arrays of size size. The interpolation object
(gsl_interp) does not save the data arrays xa and ya and only stores the
static state computed from the data. The xa data array is always assumed
to be strictly ordered, with increasing x values; the behavior for other
arrangements is not defined.
- "gsl_interp_name($interp)"
- This function returns the name of the interpolation type used by
$interp.
- "gsl_interp_min_size($interp)"
- This function returns the minimum number of points required by the
interpolation type of $interp. For example, Akima
spline interpolation requires a minimum of 5 points.
- "gsl_interp_eval_e($interp, $xa, $ya, $x, $acc)"
- This functions returns the interpolated value of y for a given point
$x, using the interpolation object
$interp, data arrays $xa
and $ya and the accelerator
$acc. The function returns 0 if the operation
succeeded, 1 otherwise and the y value.
- "gsl_interp_eval($interp, $xa, $ya, $x, $acc)"
- This functions returns the interpolated value of y for a given point
$x, using the interpolation object
$interp, data arrays $xa
and $ya and the accelerator
$acc.
- "gsl_interp_eval_deriv_e($interp, $xa, $ya, $x, $acc)"
- This function computes the derivative value of y for a given point
$x, using the interpolation object
$interp, data arrays $xa
and $ya and the accelerator
$acc. The function returns 0 if the operation
succeeded, 1 otherwise and the d value.
- "gsl_interp_eval_deriv($interp, $xa, $ya, $x, $acc)"
- This function returns the derivative d of an interpolated function for a
given point $x, using the interpolation object
interp, data arrays $xa and
$ya and the accelerator
$acc.
- "gsl_interp_eval_deriv2_e($interp, $xa, $ya, $x, $acc)"
- This function computes the second derivative d2 of an interpolated
function for a given point $x, using the
interpolation object $interp, data arrays
$xa and $ya and the
accelerator $acc. The function returns 0 if the
operation succeeded, 1 otherwise and the d2 value.
- "gsl_interp_eval_deriv2($interp, $xa, $ya, $x, $acc)"
- This function returns the second derivative d2 of an interpolated function
for a given point $x, using the interpolation
object $interp, data arrays
$xa and $ya and the
accelerator $acc.
- "gsl_interp_eval_integ_e($interp, $xa, $ya, $a, $b, $acc)"
- This function computes the numerical integral result of an interpolated
function over the range [$a, $b], using the
interpolation object $interp, data arrays
$xa and $ya and the
accelerator $acc. The function returns 0 if the
operation succeeded, 1 otherwise and the result value.
- "gsl_interp_eval_integ($interp, $xa, $ya, $a, $b, $acc)"
- This function returns the numerical integral result of an interpolated
function over the range [$a, $b], using the
interpolation object $interp, data arrays
$xa and $ya and the
accelerator $acc.
- "gsl_interp_free($interp)" - This function frees the
interpolation object $interp.
- "gsl_interp_bsearch($x_array, $x, $index_lo, $index_hi)"
- This function returns the index i of the array
$x_array such that
$x_array[i] <= x <
$x_array[i+1]. The index is searched for in the
range [$index_lo,$index_hi].
This module also includes the following constants :
- $gsl_interp_linear
- Linear interpolation
- $gsl_interp_polynomial
- Polynomial interpolation. This method should only be used for
interpolating small numbers of points because polynomial interpolation
introduces large oscillations, even for well-behaved datasets. The number
of terms in the interpolating polynomial is equal to the number of
points.
- $gsl_interp_cspline
- Cubic spline with natural boundary conditions. The resulting curve is
piecewise cubic on each interval, with matching first and second
derivatives at the supplied data-points. The second derivative is chosen
to be zero at the first point and last point.
- $gsl_interp_cspline_periodic
- Cubic spline with periodic boundary conditions. The resulting curve is
piecewise cubic on each interval, with matching first and second
derivatives at the supplied data-points. The derivatives at the first and
last points are also matched. Note that the last point in the data must
have the same y-value as the first point, otherwise the resulting periodic
interpolation will have a discontinuity at the boundary.
- $gsl_interp_akima
- Non-rounded Akima spline with natural boundary conditions. This method
uses the non-rounded corner algorithm of Wodicka.
- $gsl_interp_akima_periodic
- Non-rounded Akima spline with periodic boundary conditions. This method
uses the non-rounded corner algorithm of Wodicka.
Jonathan "Duke" Leto <jonathan@leto.net> and
Thierry Moisan <thierry.moisan@gmail.com>
Copyright (C) 2008-2011 Jonathan "Duke" Leto and Thierry
Moisan
This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.