Averages/Arithmetic mean: Difference between revisions

=={{header|D}}==

Using template to make the mean function work for higher-rank array.

<pre>module mean ;

import std.stdio ;

real mean(T)(T[] a) {

static if(is(T U : U[])) {

// recursively unfold the multi-array

T u ;

foreach(e ; a)

u ~= e ;

return u.mean() ;

} else {

// do the math

if(a.length == 0) return 0.0 ;

real sum = 0.0 ;

foreach(e ; a)

sum += e ;

return sum / a.length ;

}

}

void main() {

int[] array = [3,1,4,1,5,9];

real[][][]

multi = [[[1,2,2],[2,3,4],[4,5,7]],

[[4,1,3],[0,3,1],[4,4,6]],

[[1,3,3],[2,7,8],[9,1,5]]] ;

writefln("array : ", array.mean()) ;

writefln("multi : ", multi.mean()) ;

}</pre>