my $fi = gsl_fopen('data', 'r');
my $fo = gsl_fopen('hist', 'w');
my $h = gsl_histogram_alloc(6);
my $range = [ 1.0, 10.0, 100.0, 1000.0, 10000.0, 100000.0 ];
gsl_histogram_fread($fi, $h);
gsl_histogram_set_ranges($h,$range,7);
gsl_histogram_fprintf($fo, $h, "%3.1f", "%3.1f");
gsl_fclose($fo);
gsl_fclose($fi);