Mathematica 7 compares to other languages

[Jim Gibson]

In article
<5ebe5a7d-cbdf-4d66-a816-a7d2a0a273c9 at 40g2000prx.googlegroups.com>, Xah
Lee <xahlee at gmail.com> wrote:

> On Dec 10, 2:47 pm, John W Kennedy <jwke... at attglobal.net> wrote:
> > Xah Lee wrote:
> > > In lisp, python, perl, etc, you'll have 10 or so lines. In C or Java,
> > > you'll have 50 or hundreds lines.
> >
> > C:
> >
> > #include <stdlib.h>
> > #include <math.h>
> >
> > void normal(int dim, float* x, float* a) {
> >     float sum = 0.0f;
> >     int i;
> >     float divisor;
> >     for (i = 0; i < dim; ++i) sum += x[i] * x[i];
> >     divisor = sqrt(sum);
> >     for (i = 0; i < dim; ++i) a[i] = x[i]/divisor;
> >
> > }
> >
> > Java:
> >
> > static float[] normal(final float[] x) {
> >     float sum = 0.0f;
> >     for (int i = 0; i < x.length; ++i) sum += x[i] * x[i];
> >     final float divisor = (float) Math.sqrt(sum);
> >     float[] a = new float[x.length];
> >     for (int i = 0; i < x.length; ++i) a[i] = x[i]/divisor;
> >     return a;
> >
> > }
> 
> Thanks to various replies.
> 
> I've now gather code solutions in ruby, python, C, Java, here:
> 
> € A Example of Mathematica's Expressiveness
>   http://xahlee.org/UnixResource_dir/writ/Mathematica_expressiveness.html
> 
> now lacking is perl, elisp, which i can do well in a condensed way.
> It'd be interesting also to have javascript... and perhaps erlang,
> OCaml/F#, Haskell too.

Perl:

sub normal
{
  my $sum = 0;
  $sum += $_ ** 2 for @_;
  my $length = sqrt($sum);
  return map { $_/$length } @_;
}

-- 
Jim Gibson