Cannot set sfElementNodes to stop contouring between unrelated nodes

From: Carmen St. Jean <cstjean_at_nyahnyahspammersnyahnyah>
Date: Fri Mar 23 2012 - 09:31:35 MDT

Hello NCL-ers,

I'm trying to use a NetCDF file of NOAA/NOS' Northern Gulf of Mexico
Operational Forecast System (NGOFS) to create a contour plot of sea
surface temperature. However, the contour plot my PyNGL code produces
is not showing NGOFS as I would expect it to appear. The contour is
being drawn between nodes of the NGOFS triangular mesh that should not
be neighbors.

I attached a PNG image of the plot, where you can see that there are
extra connections being made between nodes when you compare it to how
NGOFS should look (example:
(Additionally, I think I am having projection issues, but that is a
separate issue perhaps.)

I saw that you can set the "sfElementNodes" resource to specify a set of
triangles explicitly, so I attempted to set "sfElementNodes" to the "nv"
variable of this NetCDF file. However, the dimensions of "nv" are
backwards from what sfElementNodes wants. I attempted to transpose this
2D array through several methods, but it killed my program, perhaps
because the array is too large to transpose.

Without a mask in this NetCDF file, I'm not sure of any other ways to
stop the contour from being drawn outside of the NGOFS domain. Does
anyone have any ideas? I'm pretty new to PyNGL/NCL, so there may be
something obvious I am missing. Any suggestions would be appreciated.

Here is the file I'm using for input:
(If this file does not work for you, it can be any
nos.ngofs.fields.nowcast.* file from the CO-OPS OPeNDAP server:

Thank you,

Carmen St. Jean

ncl-talk mailing list
List instructions, subscriber options, unsubscribe:

Received on Fri Mar 23 09:31:50 2012

This archive was generated by hypermail 2.1.8 : Tue Mar 27 2012 - 08:50:24 MDT