14 lines
238 B
Raku
14 lines
238 B
Raku
# <(x - <x>)²> = <x²> - <x>²
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{
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my $num, $sum, $sum2;
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sub stddev {
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my $x = shift;
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$num++;
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return sqrt(
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($sum2 += $x**2) / $num -
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(($sum += $x) / $num)**2
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);
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}
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}
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print stddev($_), "\n" for qw(2 4 4 4 5 5 7 9);
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