NAME

Math::ThinPlateSpline - Calculate and evaluate thin plate splines

SYNOPSIS

  my @control_points = (
      [$x, $y, $z],
      [$x2, $y2, $z2],
      ...
  );
  my $regularization = 0.; # default, follow control points slavishly
  
  my $tps = Math::ThinPlateSpline->new(
    \@control_points,
    $regularization
  );
  
  my $height = $tps->evaluate($x, $y);
  my $bending_energy = $tps->get_bending_energy();

  my $heights = $tps->evaluate_many([$x1, $x2, $x3...], [$y1, $y2, $y3...]);
  # $heights is now [$z1, $z2, $z3...]

DESCRIPTION

This is a small Perl/XS module for calculating and evaluating thin plate splines. If you don't know what thin plate splines are, check out the links in the "SEE ALSO" section. In a nutshell, it's ordinary splines generalized to two dimensions.

The module includes a copy of the tpsfit C++ library that was created on the basis of the tpsdemo program by Jarno Elonen.

METHODS

new

(class method)

Creates a new thin plate spline. Takes one mandatory parameter: A reference to an array of control points (at least three). Each control point has to be a reference to an array of three numbers (X, Y, Z coordinates). See SYNOPSIS.

The second parameter is optional: A measure for the regularization. See Jarno Elonen's page for details.

evaluate

Takes an x and y coordinate as arguments. Returns the z coordinate of the thin plate spline at the specified point.

get_bending_energy

Calculates and returns the thin plate spline's bending energy. Again, Jarno Elonen explains this well on his tpsdemo page.

DEPENDENCIES

Apart from Perl modules (see META.yml or Makefile.PL), this module needs the boost:ublas library to build (including headers).

SEE ALSO

Jarno Elonen's page about thin plate splines: http://elonen.iki.fi/code/tpsdemo/

Wikipedia on thin plate splines: http://en.wikipedia.org/wiki/Thin_plate_spline

AUTHOR

Steffen Mueller, <smueller@cpan.org>

COPYRIGHT AND LICENSE

The Math::ThinPlateSpline module is

Copyright (C) 2010, 2011 by Steffen Mueller

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.0 or, at your option, any later version of Perl 5 you may have available.

The included tpsfit library is

Copyright (C) 2001-2003,2005 Jarno Elonen

Copyright (C) 2010 by Steffen Mueller

This library is Free Software / Open Source with a very permissive license:

Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation. The authors make no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.

cpanm Math::ThinPlateSpline

perl -MCPAN -e shell
install Math::ThinPlateSpline