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Programming-Idioms

  • JS

Idiom #202 Sum of squares

Calculate the sum of squares s of data, an array of floating point values.

s = data.reduce((a, c) => a + c ** 2, 0)

Array.reduce uses a function to reduce the array into a single sum of all the elements' squares.

The initial accumulator's value is 0.
(defn square [x] (* x x))

(def s (->> data (map square) (reduce +)))
New implementation...
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Bart 
s = data.reduce((a, c) => a + c ** 2, 0)
(defn square [x] (* x x))

(def s (->> data (map square) (reduce +)))
(defn square [x] (* x x))

(def s (reduce + (map square data)))
(defn square [x] (* x x))

(def s (transduce (map square) + data))
var s = data.Sum(x => x * x);
var s = data.map((v) => v * v).reduce((sum, v) => sum + v);
s = sum( data**2 )
var s float64
for _, d := range data {
	s += math.Pow(d, 2)
}
def s = data.sum { it ** 2 }
sumOfSquares = sum . map (^2)
double s = Arrays.stream(data).map(i -> i * i).sum();
double s = of(data).map(x -> x * x).sum();
BigDecimal s = of(data)
    .mapToObj(String::valueOf)
    .map(BigDecimal::new)
    .map(x -> x.multiply(x))
    .reduce(BigDecimal::add)
    .get();
var
  data: array of double;
...
  s := SumOfSquares(data);
...
my $s = sum map { $_ ** 2 } @data;
f = lambda x: x * x
s = sum(map(f, data))
s = sum(i**2 for i in data)
s = data.sum{|i| i**2}
s = data.sum{ _1**2 }
let s = data.iter().map(|x| x.powi(2)).sum::<f32>();