Using reduce() with tuples created by zip()

[Craig Dillabaugh]

On Thursday, 31 October 2013 at 19:23:56 UTC, Philippe Sigaud
wrote:
> I think reduce takes two arguments: the growing seed and the 
> current front.
> You're trying to get (a[0]-b[0])^^2 + (a[1]-b[1])^^2 + ..., 
> right?
Yep. The (e[1]-e[0])*(e[1]-e[0]) bit was, I supposed was
effectively
calculating (a[0]-b[0])^^2 and so on.  I forgot about the ^^2 in
D.

>
> Try this:
>
> module euclid;
>
>
> import std.stdio;
>
> double euclid_dist( double[] pt1, double[] pt2 ) {
>     assert( pt1.length == pt2.length );
>     import std.algorithm;
>     import std.math;
>     import std.range;
>
>     return sqrt(0.0.reduce!( (sum,pair) => sum + 
> (pair[0]-pair[1])^^2
> )(zip(pt1, pt2)));
> }
>
> void main()
> {
>     double[] arr1 = [0.0, 1.0, 0.1];
>     double[] arr2 = [1.0, -1.0, 0.0];
>     writeln(euclid_dist(arr1,arr2));
> }
>
>
>
> On Thu, Oct 31, 2013 at 8:12 PM, Craig Dillabaugh <
> cdillaba at cg.scs.carleton.ca> wrote:
>
clip
>> Cheers,
>> Craig

Thanks, I will try both your, and Bearophile's ideas and see if I
can figure out how they work.
Craig