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Hello:
I wish to contribute a module for Simple Interest
calculations.
The file Simpint.pm is attached.
Brad Yourth
I have no home page
My preferred user-id is B-YOURTH
Module description...Math::Simpint
My module is an extension of the Math:: module.
It provides 12 functions/subroutines for
computing
interest, interest rate, time/dates, present value and future
value.
The module was created with h2xs and is POD
documented.
Thanks,
Brad Yourth
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## Copyright (c) 2001 by Brad Yourth
## All rights reserved.
##
## This package is free software; you can redistribute it
## and/or modify it under the same terms as Perl itself.
package Math::Simpint;
use 5.006;
use strict;
use warnings;
require Exporter;
use Date::Calc qw/Date_to_Days Add_Delta_Days/;
our @ISA = qw(Exporter);
our %EXPORT_TAGS = ( 'all' => [ qw(
) ] );
our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );
our @EXPORT = qw(
int_yrs
int_dates
rate_yrs
rate_dates
principal_yrs
time_days
time_yrs
time_date
fv_yrs
fv_dates
pv_yrs
pv_dates
);
our $VERSION = '0.01';
sub int_yrs {
$_[0] * $_[1] * $_[2] * 0.01;
}
sub int_dates {
my $t = dates_to_yrs( $_[2],$_[3] );
$_[0] * $_[1] * .01 * $t;
}
sub rate_yrs {
$_[1] / $_[0] / $_[2] * 100;
}
sub rate_dates {
my $t = dates_to_yrs( $_[2],$_[3] );
100 * $_[1] / $_[0] * $t;
}
sub principal_yrs {
$_[0] / $_[1] / $_[2];
}
sub time_days {
365 * 100 * $_[1] / $_[0] / $_[2];
}
sub time_yrs {
100 * $_[1] / $_[0] / $_[2];
}
sub time_date {
my $days = 365 * 100 * $_[1] / $_[0] / $_[2];
$_[3] =~ /(\d+)\/(\d+)\/(\d+)/;
join("/", Add_Delta_Days( $1,$2,$3,$days));
}
sub fv_yrs {
$_[0] + $_[0] * $_[1] * $_[2] * 0.01;
}
sub fv_dates {
my $t = dates_to_yrs( $_[2],$_[3] );
$_[0] + $_[0] * $_[1] * .01 * $t;
}
sub pv_yrs {
$_[0] / ( 1 + $_[1] * $_[2] * 0.01 );
}
sub pv_dates {
my $t = dates_to_yrs( $_[2],$_[3] );
$_[0] /( 1 + $_[1] * .01 * $t );
}
sub dates_to_yrs {
$_[0] =~ /(\d{4})\/(\d+)\/(\d+)/;
my $d1 = Date_to_Days($1,$2,$3);
$_[1] =~ /(\d{4})\/(\d+)\/(\d+)/;
my $d2 = Date_to_Days($1,$2,$3);
($d2 - $d1)/365;
}
1;
__END__
=head1 NAME
Math::Simpint - Perl extension to Math:: for Simple Interest
=head1 PREFACE
Math::Simpint contains subroutines for simple interest
calculations. Subroutines are provided for these formulas
I = Prt S = P(1 + rt) P = S / (1 + rt)
t = I/Pr r = I/Pt P = I/rt
and include the use of calendar date strings thanks to
several subroutines from Steffen Bryer's Date::Calc
module (which is required).
=head1 SYNOPSIS
use Math::Simpint;
=head1 FUNCTIONS
=head2 int_yrs
C<$interest = int_yrs( $prin, $rate, $years );>
Implements I = Prt where $years is in years.
Returns amount of interest. $rate is a percent, NOT a decimal.
=head2 int_dates
C<$interest = int_dates( $prin, $rate, "yyyy/mm/dd","yyyy/mm/dd" );>
For I = Prt given two date strings as shown. First date string is start date.
Returns interest earned. $rate is a percent, NOT a decimal.
=head2 rate_yrs
C<$rate = rate_yrs( $prin, $int, $years );>
Returns the annual interest rate as a percent, given $years in years.
=head2 rate_dates
C<$rate = rate_dates( $prin, $int, "yyyy/mm/dd","yyyy/mm/dd" );>
Returns rate % that yields $int interest on $prin between two dates.
First date string is start date.
=head2 principal_yrs
C<$prin = principal_yrs( $int, $rate, $years );>
For P = I/rt. $rate is a %, NOT a decimal. Returns principal needed.
=head2 time_days
C<$days = time_days( $int, $prin, $rate );>
Returns number of days needed for $prin to earn $int at $rate %.
=head2 time_yrs
C<$yrs = time_yrs( $prin, $int, $rate );>
Returns time in years needed for $prin to earn $int at $rate %.
=head2 time_date
C<$datestring = time_date( $prin, $int, $rate, "yyyy/mm/dd" );>
Returns date at which $prin will earn $int at $rate %. $datestring is in format "yyyy/mm/dd".
=head2 fv_yrs
C<$futurevalue = fv_yrs( $prin, $rate, $years );>
Implements S = P( 1 + rt ). $rate is a per cent. $years is in years.
=head2 fv_dates
C<$futurevalue = fv_dates( $prin, $rate, ""yyyy/mm/dd","yyyy/mm/dd" );>
Implements S = P( 1 + rt ) between two given dates. First date string is start date.
=head2 pv_yrs
C<$prin = pv_yrs( $futurevalue, $rate, $years );>
Implements P = S /( 1 + rt ) given $years in years. $rate is a per cent.
=head2 pv_dates
C<$prin = pv_dates( $futurevalue, $rate, ""yyyy/mm/dd","yyyy/mm/dd" );>
Implements P = S /( 1 + rt ) given two dates. First date is start date. $rate is a per cent.
=head2 dates_to_yrs
C<$yrs = dates_to_yrs( "yyyy/mm/dd","yyyy/mm/dd" );>
Computes number of years between two dates for some subs above. Intended primarily for internal use of other functions.
=head1 EXPORT
None by default.
=head1 AUTHOR
Brad Yourth
I<[EMAIL PROTECTED]>
=head1 SEE ALSO
Date::Calc for Date_to_Days and Add_Delta_Days functions
=head1 DISCLAIMER
This package is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
=cut
