Re^7: Calculate aircraft headings from GPS data for google kml display

I think this approach might work. Please note that this is just "shooting-from-the-hip" psuedo-code.

my %aircraft_ids;

for my $row ( INPUT_ROWS ) {
    my ($row_id,$a_id,@row_fields) = split(',', $row);

    if ( exists( $aircraft)ids{$a_id} ) {
        my $prior_fields = $aircraft_ids{$a_id};

        # do calcs here comparing current row data to priors
    }

    # and save these data points for the next time the ID is seen.
    $aircraft_ids{$a_id} = \@row_fields;
}
[download]

There are several way you can represent the row data in the array, but this should point you in the right direction.

You must always remember that the primary goal is to drain the swamp even when you are hip-deep in alligators.

Comment on Re^7: Calculate aircraft headings from GPS data for google kml display Download Code