NAME

Time::TT::InterpolatingRealisation - TT realised by interpolation

SYNOPSIS

        use Time::TT::InterpolatingRealisation;

        $rln = Time::TT::InterpolatingRealisation->new($interpolator);

        $tai_instant = $rln->to_tai($instant);
        $instant = $rln->from_tai($tai_instant);
        $rln1_instant = $rln0->to_realisation($rln1, $rln0_instant);
        $rln0_instant = $rln0->from_realisation($rln1, $rln1_instant);

DESCRIPTION

This class implements a realisation of Terrestrial Time (TT) by interpolation between known points of correlation between the realisation and International Atomic Time (TAI). See Time::TT::Realisation for the interface.

CONSTRUCTOR

Normally one won't use this constructor directly. See the tt_realisation function in Time::TT, which will construct a range of published realisations, most of which are implemented using this class. Use this directly only if the realisation that you desire is not available by that means.

Time::TT::InterpolatingRealisation->new(INTERPOLATOR)

Constructs and returns an object representing a realisation of TT that is defined by isolated points of correlation between it and TAI. The INTERPOLATOR argument must be an object of a subclass of Math::Interpolator, supplying the x and y methods. The x coordinate of the interpolator's curve must represent TAI, and the y coordinate the realisation of interest. Times on both coordinates are represented as the number of seconds since the 1958 epoch, as described in Time::TT. All numbers must be Math::BigRat objects.

The class Time::TT::OffsetKnot may be useful in building the required interpolator.

METHODS

$rln->to_tai(INSTANT)

$rln->from_tai(TAI_INSTANT)

These methods are part of the standard Time::TT::Realisation interface.

SEE ALSO

Math::BigRat, Math::Interpolator, Time::TT, Time::TT::OffsetKnot, Time::TT::Realisation

AUTHOR

Andrew Main (Zefram) <zefram@fysh.org>

COPYRIGHT

Copyright (C) 2006, 2007, 2010, 2012 Andrew Main (Zefram) <zefram@fysh.org>

LICENSE

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.