In article
<5ebe5a7d-cbdf-4d66-a816-a7d2a0a27...@40g2000prx.googlegroups.com>, Xah
Lee <xah...@gmail.com> wrote:
> On Dec 10, 2:47 pm, John W Kennedy <jwke...@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
--
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