Bug #95428 for Temperature-Windchill: More a feature Request than a bug report

Seems in Canada it is normal to give the windchill at wind speeds 5kph and below I have added in a sub that uses the environment Canada calculation which is $temp +((-1.59+0.1345*$temp)/5)*$windspeed Seem NOAA does accept windchill at below 4mph as well they just take it as the ambient temperature. Here is the new sub and Pod I have attached a patched version and a test as well enjoy

#!perl -T use Test::More tests => 17; use_ok('Temperature::Windchill', 'windchill_ca'); # check a range of valid values { my $wc = sub { return 0 + sprintf('%.1f' , windchill_ca(@_)) }; my @valid = ( # temperature, windspeed, windchill [ 5, 1, 4.8 ], [ 0, 2, -0.6 ], [ -5, 3, -6.4 ], [ -10, 4, -12.3 ], [ -15, 5, -18.6 ], [ -20, 1, -20.9 ], [ -25, 2, -27.0 ], [ -30, 3, -33.4 ], [ -35, 4, -40.0 ], [ -40, 5, -47.0 ], [ -45, 1, -46.5 ], [ -10, 2, -11.2 ], [ -10, 3, -11.8 ], [ -10, 4, -12.3 ], [ -10, 5, -12.9 ], [ -45, 20, -62.0], ); for (@valid) { my ($temp, $speed, $chill) = @$_; is($wc->($temp, $speed), $chill); } }

package Temperature::Windchill; use strict; use warnings; use base 'Exporter'; use vars qw( $VERSION @EXPORT_OK ); $VERSION = '0.04'; @EXPORT_OK = qw( windchill_si windchill_us windchill_ca); =head1 NAME Temperature::Windchill - calculate effective temperature on exposed skin =head1 SYNOPSIS use Temperature::Windchill qw/ windchill_us windchill_si windchill_ca/; # calculate windchill in American units (Fahrenheit/MPH) $wc_us = windchill_us($temp_in_F, $windspeed_in_MPH); # calculate windchill in International units (Celsius/KPH) $wc_si = windchill_si($temp_in_C, $windspeed_in_KPH); # calculate windchill for Canada in International units (Celsius/KPH) $wc_si = windchill_ca($temp_in_C, $windspeed_in_KPH); =head1 DESCRIPTION This module implements the standard US National Weather Service windchill temperature ("WCT") index formula, which replaced the 1945 Siple and Passel WCT formula in 2001. From the US National Oceanic and Atmospheric Administration ("NOAA") website: =over 4 I<< The windchill temperature is how cold people and animals feel when outside. Windchill is based on the rate of heat loss from exposed skin caused by wind and cold. As the wind increases, it draws heat from the body, driving down skin temperature and eventually the internal body temperature. Therefore, the wind makes it B<feel> much colder. If the temperature is 0 degrees Fahrenheit and the wind is blowing at 15 mph, the windchill is -19 degrees Fahrenheit. At this windchill temperature, exposed skin can freeze in 30 minutes. >> I<< ... The current formula uses advances in science, technology, and computer modeling to provide a more accurate, understandable, and useful formula for calculating the dangers from winter winds and freezing temperatures. Wind Chill Temperature Comparison (Old vs. New) Clinical trials were conducted at the Defence and Civil Institute of Environmental Medicine in Toronto, Canada, and the trial results were used to improve the accuracy of the new formula and determine frostbite threshold values. >> =back =head2 Limitations =over 4 =item WCT is only defined for temperatures above -50 F (-45.5 C) and below 50 F (10 C). =item WCT is normally only defined for wind speeds above 3 MPH (4.8 KPH) and below 110 MPH (177 KPH). Canadian forcasters do use an extended formula that goes all the way down to 0 KPH. =item WCT applies to living tissue at the height of five feet (152 cm), the typical height of an adult human face. =item Bright sunshine may increase the windchill temperature by 10 to 18 F (5 to 10 C). =back =head1 FUNCTIONS Neither function provided by this module attempts to verify that either the temperature or the windspeed supplied by the user are within the valid input range. I<Caveat programmor>. =head2 windchill_us( $temperature, $windspeed ) Calculates the windchill in United States ("US") units, i.e. temperature in degrees Fahrenheit and windspeed in miles per hour. Example: # what's the windchill at 10 F and 15 MPH? my $chill = windchill_us( 10, 15 ); print "the windchill is: $chill F"; =cut sub windchill_us { my ($temp, $windspeed) = @_; my $pow = $windspeed ** 0.16; return 35.74 + (0.6215 * $temp) - (35.75 * $pow) + (0.4275 * $temp * $pow); } =head2 windchill_si( $temperature, $windspeed ) Calculates the windchill in International ("SI") units, i.e. temperature in degrees Celsius and windspeed in kilometers per hour. Example: # what's the windchill at -5 C and 20 KPH? my $chill = windchill_si( -5, 20 ); print "the windchill is: $chill C"; =cut sub windchill_si { my ($temp, $windspeed) = @_; my $pow = $windspeed ** 0.16; return 13.12 + (0.6215 * $temp) - (11.37 * $pow) + (0.3965 * $temp * $pow); } =head2 windchill_ca( $temperature, $windspeed ) Calculates the windchill in International ("SI") units, i.e. temperature in degrees Celsius and windspeed in kilometers per hour but extends down to 0 kph which is customary to do in Canada. Example: # what's the windchill at -5 C and 2 KPH? my $chill = windchill_ca( -5, 2 ); print "the windchill is: $chill C"; =cut sub windchill_ca { my ($temp, $windspeed) = @_; return windchill_si($temp, $windspeed) if $windspeed >5; return ($temp +((-1.59+0.1345*$temp)/5)*$windspeed) ; } =head1 ADDITIONAL RESOURCES =over 4 =item L<http://www.weather.gov/os/windchill/> =item L<http://www.ofcm.gov/jagti/r19-ti-plan/pdf/entire_r19_ti.pdf> =back =head1 AUTHOR John Trammell, C<< <johntrammell at gmail.com> >> =head1 BUGS Please report any bugs or feature requests to C<bug-temperature-windchill at rt.cpan.org>, or through the web interface at L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Temperature-Windchill>. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. =head1 SUPPORT You can find documentation for this module with the perldoc command. perldoc Temperature::Windchill You can also look for information at: =over 4 =item * RT: CPAN's request tracker L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Temperature-Windchill> =item * AnnoCPAN: Annotated CPAN documentation L<http://annocpan.org/dist/Temperature-Windchill> =item * CPAN Ratings L<http://cpanratings.perl.org/d/Temperature-Windchill> =item * Search CPAN L<http://search.cpan.org/dist/Temperature-Windchill> =back =head1 ACKNOWLEDGEMENTS I would like to thank all the attendees of the Frozen Perl 2008 conference, who inspired me to write this module. =head1 COPYRIGHT & LICENSE Copyright 2008 John Trammell, all rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. =cut 1;