# Idiom #208 Formula with arrays

Given the arrays a,b,c,d of equal length and the scalar e, calculate a = e*(a+b*c+cos(d)).
Store the results in a.

``````for i := 0 to High(a) do
a[i] = e*(a[i]+b[i]*c[i]+cos(d[i]);``````
``#include <math.h>``
``````  for (i=0; i<n; i++)
a[i] = e*(a[i]+b[i]*c[i]+cos(d[i]);``````
``a = e*(a+b*c+cos(d))``
``import "math"``
``````func applyFormula(a, b, c, d []float64, e float64) {
for i, v := range a {
a[i] = e * (v + b[i] + c[i] + math.Cos(d[i]))
}
}``````
``a.forEach((aa, i) => a[i] = e * (aa + b[i] * c[i] + Math.cos(d[i])))``
``````\$a[\$_] = \$e * (\$a[\$_] + \$b[\$_] * \$c[\$_] + cos \$d[\$_]) for 0 .. \$#a;
``````
``import math``
``````for i in xrange(len(a)):
a[i] = e*(a[i] + b[i] + c[i] + math.cos(a[i]))
``````
``import math``
``a = [e*(a[i] + b[i] + c[i] + math.cos(d[i])) for i in range(len(a))]``
``a = a.zip(b,c,d).map{|i,j,k,l| e*(i+j*k+Math::cos(l)) }``
``````for i in 0..a.len() {
a[i] = e * (a[i] + b[i] * c[i] + d[i].cos());
}``````

tkoenig