PDL::GSL::INTERP(3pm)

1INTERP(3)             User Contributed Perl Documentation            INTERP(3)
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NAME

6       PDL::GSL::INTERP - PDL interface to Interpolation routines in GSL
7

DESCRIPTION

9       This is an interface to the interpolation package present in the GNU
10       Scientific Library.
11

SYNOPSIS

13          use PDL;
14          use PDL::GSL::INTERP;
15
16          my $x = sequence(10);
17          my $y = exp($x);
18
19          my $spl = PDL::GSL::INTERP->init('cspline',$x,$y);
20
21          my $res = $spl->eval(4.35);
22          $res = $spl->deriv(4.35);
23          $res = $spl->deriv2(4.35);
24          $res = $spl->integ(2.1,7.4);
25

FUNCTIONS

27   init()
28       The init method initializes a new instance of INTERP. It needs as input
29       an interpolation type and two piddles holding the x and y values to be
30       interpolated. The GSL routines require that x be monotonically
31       increasing and a quicksort is performed by default to ensure that. You
32       can skip the quicksort by passing the option {Sort => 0}.
33
34       The available interpolation types are :
35
36       linear
37       polynomial
38       cspline (natural cubic spline)
39       cspline_periodic  (periodic cubic spline)
40       akima (natural akima spline)
41       akima_periodic  (periodic akima spline)
42
43       Please check the GSL documentation for more information.
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45       Usage:
46
47           $blessed_ref = PDL::GSL::INTERP->init($interp_method,$x,$y,$opt);
48
49       Example:
50
51           $x = sequence(10);
52           $y = exp($x);
53
54           $spl = PDL::GSL::INTERP->init('cspline',$x,$y)
55           $spl = PDL::GSL::INTERP->init('cspline',$x,$y,{Sort => 1}) #same as above
56
57           # no sorting done on x, user is certain that x is monotonically increasing
58           $spl = PDL::GSL::INTERP->init('cspline',$x,$y,{Sort => 0});
59
60   eval()
61       The function eval returns the interpolating function at a given point.
62       By default it will barf if you try to extrapolate, to comply silently
63       if the point to be evaluated is out of range pass the option
64       {Extrapolate => 1}
65
66       Usage:
67
68           $result = $spl->eval($points,$opt);
69
70       Example:
71
72           my $res = $spl->eval($x)
73           $res = $spl->eval($x,{Extrapolate => 0}) #same as above
74
75           # silently comply if $x is out of range
76           $res = $spl->eval($x,{Extrapolate => 1})
77
78   deriv()
79       The deriv function returns the derivative of the interpolating function
80       at a given point. By default it will barf if you try to extrapolate, to
81       comply silently if the point to be evaluated is out of range pass the
82       option {Extrapolate => 1}
83
84       Usage:
85
86           $result = $spl->deriv($points,$opt);
87
88       Example:
89
90           my $res = $spl->deriv($x)
91           $res = $spl->deriv($x,{Extrapolate => 0}) #same as above
92
93           # silently comply if $x is out of range
94           $res = $spl->deriv($x,{Extrapolate => 1})
95
96   deriv2()
97       The deriv2 function returns the second derivative of the interpolating
98       function at a given point. By default it will barf if you try to
99       extrapolate, to comply silently if the point to be evaluated is out of
100       range pass the option {Extrapolate => 1}
101
102       Usage:
103
104           $result = $spl->deriv2($points,$opt);
105
106       Example:
107
108           my $res = $spl->deriv2($x)
109           $res = $spl->deriv2($x,{Extrapolate => 0}) #same as above
110
111           # silently comply if $x is out of range
112           $res = $spl->deriv2($x,{Extrapolate => 1})
113
114   integ()
115       The integ function returns the integral of the interpolating function
116       between two points.  By default it will barf if you try to extrapolate,
117       to comply silently if one of the integration limits is out of range
118       pass the option {Extrapolate => 1}
119
120       Usage:
121
122           $result = $spl->integ($a,$b,$opt);
123
124       Example:
125
126           my $res = $spl->integ($a,$b)
127           $res = $spl->integ($a,$b,{Extrapolate => 0}) #same as above
128
129           # silently comply if $a or $b are out of range
130           $res = $spl->eval($a,$b,{Extrapolate => 1})
131

BUGS

133       Feedback is welcome.
134

AUTHOR

143       This file copyright (C) 2003 Andres Jordan
144       <andresj@physics.rutgers.edu> All rights reserved. There is no
145       warranty. You are allowed to redistribute this software/documentation
146       under certain conditions. For details, see the file COPYING in the PDL
147       distribution. If this file is separated from the PDL distribution, the
148       copyright notice should be included in the file.
149
150       The GSL interpolation module was written by Gerard Jungman.
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154perl v5.28.0                      2018-07-23                         INTERP(3)

NAME

DESCRIPTION

SYNOPSIS

FUNCTIONS

BUGS

SEE ALSO

AUTHOR