zeroclickinfo-goodies/lib/DDG/Goodie/ReverseResistorColours.pm

80 lines
2.6 KiB
Perl

package DDG::Goodie::ReverseResistorColours;
#ABSTRACT: Do the reverse of what ResistorColors.pm does.
use strict;
use DDG::Goodie;
use utf8;
triggers query_raw => qr/^resistors?|resistors?$/i;
zci is_cached => 1;
zci answer_type => 'ohms';
primary_example_queries 'red yellow white gold resistor';
secondary_example_queries 'resistor red yellow white';
description 'find resistance based on colour bands';
name 'ReverseResistorColours';
code_url 'https://github.com/duckduckgo/zeroclickinfo-goodies/lib/DDG/Goodie/ReverseResistorColours.pm';
category 'reference';
topics 'science';
my %coloursToDigits = (
'black' => { value => 0, tolerance => '' },
'brown' => { value => 1, tolerance => 1, },
'red' => { value => 2, tolerance => 2 },
'orange' => { value => 3, tolerance => '' },
'yellow' => { value => 4, tolerance => 5 },
'green' => { value => 5, tolerance => .5 },
'blue' => { value => 6, tolerance => .25 },
'violet' => { value => 7, tolerance => .1 },
'grey' => { value => 8, tolerance => .05 },
'white' => { value => 9, tolerance => '' },
'gold' => { value => '', tolerance => 5 },
'silver' => { value => '', tolerance => 10 },
);
handle query_raw => sub {
s/gray/grey/g; #learn how to spell 'grey' right
s/purple/violet/g; #because we can say both
s/ ?resistors? ?//;
my $count = 0;
my $resistance = 0;
my @colours = (split(' ', $_));
my $marginE = 0;
my $append = '';
if ((scalar(@colours) != 3) && (scalar(@colours) != 4)) { return };
foreach my $colour (@colours) {
if (!exists $coloursToDigits{$colour}) { return };
}
$resistance += ($coloursToDigits{$colours[0]}{value} * 10);
$resistance += $coloursToDigits{$colours[1]}{value};
for (my $i = 0; $i < $coloursToDigits{$colours[2]}{value}; $i++) {
$resistance = $resistance * 10;
}
my $mult = $coloursToDigits{$colours[2]}{value};
if (exists $colours[3]) {
$marginE = $coloursToDigits{$colours[3]}{tolerance};
} else {
$marginE = 20;
}
if ($resistance > 1000 && $resistance < 999999) {
$resistance = $resistance / 1000;
$append = 'k';
}
if ($resistance > 1000000 && $resistance < 999999999) {
$resistance = $resistance / 1000000;
$append = 'M';
}
if ($resistance > 1000000000) {
$resistance = $resistance / 1000000000;
$append = "G";
}
#U+2126 is the ohm symbol, U+00B1 is the plus-minus sign.
my $answer = "A $_ resistor has a resistance of $resistance $append\x{2126} \x{00B1} $marginE\%.";
my $source = '<a href="https://en.wikipedia.org/wiki/Electronic_color_code">More at Wikipedia</a>';
return $answer, html => "$answer $source";
};
1;