Re: [idvusers] Draw particle trajectories


One way to do this is to place trajectory locations in a text file. Of
course the text file
must be formatted correctly. Below is a snipet from one I have:
(index) -> (Time,Latitude,Longitude,Altitude,Etime)
Time[fmt="yyyyddd HH"], Latitude, Longitude[scale=-1],
Altitude[unit="m"], Etime
2008001 0, 10.0, 10.0, 10000.0, 0.0
2008001 1, 10.34, 13.2194, 11766.8578, 0.02
2008001 2, 11.167554580696, 16.150820011736133, 14220.875049638309, 0.04
2008001 3, 12.33999897817454, 18.682936996489325, 17475.056508055397, 0.06
2008001 4, 13.704117531350105, 20.540947249152726, 21580.184564853265, 0.08
2008001 5, 15.069620796561924, 21.3197634115097, 26413.08760108634, 0.1
2008001 6, 16.199835276607487, 20.60385903052617, 31568.98582695971, 0.12
2008001 7, 16.83571786924921, 18.189376225419107, 36346.04828940692, 0.14
2008001 8, 16.761974192261782, 14.31447234541302, 39928.66594615809, 0.16
2008001 9, 15.89289893366295, 9.690020530091402, 41746.18005596365, 0.18
2008001 10, 14.320067479253161, 5.213110177829589, 41757.146245819575, 0.2

Select the file by: Dashboard --> Data Choosers --> Files.
o navigate to the file;
o use the Data Source Type: Text Point and Trajectory Data files;
o click the Add Source button.

Once the text file is shown in the Data Sources pane, go to Dashboard
--> Field Selector and:
o  in the Displays pane, select display: Track Colored by Parameter.
o  in the Fields pane, choose the elapsed time field to color the
trajectory by,
   x  open, Track, in the field pane,
   x  select, Etime, the elapsed time field,
   x  click the, OK, button in the Field Selector;
o  view the, Map View, window.


Jong Bor Lee wrote:
I have been contacted by a professor who is interested in viewing the
trajectory of particles under wind currents. The vector field that models
wind is available and a student is already working in the calculation of the
trajectory, so the main problem right now is visualization. I was asked
about this. Is there any functionality in idv that would allow to do this?

After inspecting idv, I wonder if writing a Jython script would be a good
approach. Is it possible to modify the behaviour of the program so that a
point is drawn on the map when the mouse is clicked? And then, would it be
possible to use the Unidata API (as specified in the Javadoc) in order to
draw this particle moving? Maybe I'm asking too much from jython scripts,
and this could only be achieved writing a new version of idv?

I should make clear I have only known idv for a few hours. It was the
professor who introduced me to this program and asked implementing this
"trajectory viewer". This was conceived as a standalone application, but
then, it would be a waste of time to implement this from scratch, since idv
has enough tools for visualization and he uses idv most of the time.

All suggestions are welcome.

Best regards,
Jong Bor Lee.
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