Thank you for all the comments. But my main problem is still how to loop around all these big dataset and calculate the headings. i think the logic should be something like this:

for ($aircraft_id){
   $current_point_x = $latitude
   $current_point_y = $longitude
   $waypoint_x = $latitude_next
   $waypoint_y = $longitude_next

   //do some calculations on calculate headings !
   //output headings
}

[download]

Any ideas to parse through all these data and do calculations, the data is organised in a way that there are different aircraft in the dataset, but it can be identified by aircraft_id, and they are ordered by gps_time column, how could i get my two continuous points and calculate the heading. In Python, i could use dictionary to do that, as to perl, i don't know. help please !

thank you!

Si

In reply to Re^2: Calculate aircraft headings from GPS data for google kml display by hujunsimon
in thread Calculate aircraft headings from GPS data for google kml display by hujunsimon

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.