wind vectors overlay problem

From: Greg Thompson (gthompsn AT XXXXXX)
Date: Fri Mar 28 2003 - 10:02:15 MST

Could someone help me diagnose a problem I'm having when overlaying
wind vectors on a wind-speed contour plot? Here's what I'm trying
to do.

 1. create a wind speed contour object called "cn_wspd"
 2. create a duplicate of cn_wspd as "cn_wspd2"
 3. create wind barb (vector) object called "wind_vectors"
 4. create a graphic with wind_vectors overlayed on cn_wspd2

I can accomplish this just fine. Now for the problem.

 5. advance frame
 6. create a streamline object called "streams"
 7. overlay streams on top of the original "cn_wspd" (the copy
     of wind speed that SHOULD not contain wind barbs). Yet
     my final graphic shows both the wind barbs and the streamlines
     as if I'm overlaying streams onto cn_wspd2.

Here's my code snipet:

        cn_wspd2 = cn_wspd
        overlay(cn_wspd2, wind_vectors)


        overlay(cn_wspd, streams)

The second draw produces both overlays as if cn_wspd already had
the wind_vectors object overlayed. Why? Isn't "cn_wspd2" a
total copy of "cn_wspd" and independent?


-- Greg T. NCAR/RAP
ncl-talk mailing list
ncl-talk AT

This archive was generated by hypermail 2b29 : Fri Mar 28 2003 - 13:15:04 MST