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langs a-z

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Ingy döt Net 2013-04-10 22:43:41 -07:00
parent db842d013d
commit d066446780
11389 changed files with 98361 additions and 1020 deletions
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37
Task/Euler-method/Perl-6/euler-method.pl6 Normal file
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sub euler ( &f, $y0, $a, $b, $h ) {
my $y = $y0;
my @t_y;
for $a, * + $h ... * > $b -> $t {
@t_y[$t] = $y;
$y += $h * f( $t, $y );
}
return @t_y;
}
my $COOLING_RATE = 0.07;
my $AMBIENT_TEMP = 20;
my $INITIAL_TEMP = 100;
my $INITIAL_TIME = 0;
my $FINAL_TIME = 100;
sub f ( $time, $temp ) {
return -$COOLING_RATE * ( $temp - $AMBIENT_TEMP );
}
my @e;
@e[$_] = euler( &f, $INITIAL_TEMP, $INITIAL_TIME, $FINAL_TIME, $_ ) for 2, 5, 10;
say 'Time Analytic Step2 Step5 Step10 Err2 Err5 Err10';
for $INITIAL_TIME, * + 10 ... * >= $FINAL_TIME -> $t {
my $exact = $AMBIENT_TEMP + ($INITIAL_TEMP - $AMBIENT_TEMP)
* (-$COOLING_RATE * $t).exp;
my $err = sub { @^a.map: { 100 * abs( $_ - $exact ) / $exact } }
my ( $a, $b, $c ) = map { @e[$_][$t] }, 2, 5, 10;
say $t.fmt('%4d '), ( $exact, $a, $b, $c )».fmt(' %7.3f'),
$err.([$a, $b, $c])».fmt(' %7.3f%%');
}