20040602: IDV - linux - point data files and displays

> The netcdf file name must include the word "metar."  Is this specific to the IDV or is it 
> part of netcdf conventions?  Is there a way to not include "metar" in the file name for 
> data that is not metar data?
Hi Stu,
You probably forgot but,  normally the IDV uses a set of patterns (e.g., 
"*metar*) to figure out what kind of data a selected
file is. However, in the File chooser you can explicitly specify the 
type of data you are selecting.

> The sample metar file I have has variable "elevation" but changing the 
> elevation value does not appear to move the display off the surface at elevation=0.  Is 
> there a way to plot point observations at true altitude or depth?
>
>  
If you look at the source code in:
ucar/unidata/data/point/PointObFactory.java
the line:
           int altIndex = type.getIndex(RealType.Altitude);
is where we are looking for altitude information. If you are not getting 
it perhaps your data set needs to be modified?


> Is there a way to make new plot symbols to match new data types, symbols which 
> are not in the set provided?  How can they be made to depend on the numerical 
> value of a variable, as does the wind barb display?  For example, circles of 
> various sizes to indicate a density.
>
>  

Right now there is no end-user way to define new symbols. The symbol 
types (TextSymbol, ValueSymbol, Windbarb,  WeatherSymbol)
we use are hard coded in the station model editor  
(ucar/unidata/ui/symbol/StationModelCanvas) and their use is defined in the
StationModelDisplayable class (in the makeShapes(PointOb ob) method).  
You would need to generalize the StationModelCanvas class
to be able to import new symbol types and then would need to change 
StationModelDisplayable to defer to the unknown symbol objects
when creating the line arrays.

> Can a plot symbol be made 3d, for example, spheres?
>
>
>  

The StationModelDisplayable creates the symbols using low-level visad 
line arrays. I guess whatever symbols that supports is what could 
possibly be displayed.

-Jeff