Hi Derek,
Your polar projection has coordinate data which is 2-dimensional, that
is the longitudes and latitudes are defined on i,j index coordinate
grid. At each i,j index pair there is a longitude, a latitude, and the
value. Once you've accessed this data in Ferret, you'll use the
curvilinear form of graphics calls to visualize the data.
What I would do is just write these three things to your ascii file,
one longitude, latitude, value per record, with i varying fastest.
Then define a grid which has x and y axes that are just the index
values of the curvilinear coordinate variables:
yes? let nx = 140 ! or whatever the number of values
is for your grid
yes? let ny = 80
yes? define axis/x=1:`nx`:1 xindex
yes? define axis/y=1:`ny`:1 yindex
yes? define grid/x=xindex/y=yindex grid_ij
yes? file/var="xlon,ylat,value"/grid=grid_ij myfile.dat
yes? FILL value, xlon, ylat
Derek Tsui wrote:
Sorry I'm not sure if there were a response since I sent out the
question before subscribing.
Thanks,
Derek
---------- Forwarded message ----------
From: Derek Tsui <i.am.mr.sleepyhead@xxxxxxxxx>
Date: Wed, Apr 22, 2009 at 5:07 PM
Subject: reading ascii in polar stereographic projection
To: ferret_users@xxxxxxxx
I have a dataset in polar stereographic projection, ascii
format, that I am trying to load into ferret and plot. It is 3 columns
of data. longitutde, latitude, value. I can format it in any way.
I've tried the general script in the "Reading an ascii file: longitute
latitute variable" thread but it doesn't seem to work in my case.
Any help would be much appreciated.
Thank you,
Derek
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