Re: [ferret_users] plotting along-track sea level anomaly

[Prasad Thoppil <thoppil@xxxxxxxxxxxxxxx>]

Hi,

I have received this solution from Mick. Here it is...

The longitude and latitude values are 1:185877 along the X-axis but the 
SLA data are along the Y-axis. This does not seem to be the usual 
situation where one would expect triplet (lon,lat,value) to be along the 
same axis. This is the source of the problem.

An easy fix is to regrid the SLA along the same axis using RESHAPE.

let RES_SLA_sla = reshape(SLA, latitudes)

Then plot RES_SLA

go polymark polygon/hlim=50:70/vlim=0:10N longitudes latitudes RES_SLA 
square

Hope this helps


Prasad.


> > Hi
> >
> > I have downloaded along-track sea level anomalies from
> > ftp://ftp.cls.fr/pub/oceano/AVISO/SSH/duacs/global/nrt/sla/en/
> >
> > The data file looks something like this:
> >
> > currently SET data sets:
> > res_oer_en_20346_20364.nc  (default)
> > name     title                             I         J         
> > K         L
> > DELTAT   Time gap between two measuremen  ...       ...       
> > ...       ...
> > NBPOINTS Number of measurements for each  ...       ...       ...
> > 1:472
> > CYCLES   Cycle numbers for each pass      1:1       ...       ...
> > 1:472
> > LONGITUDES
> >          Longitude of each measurement    1:185877  ...       
> > ...       ...
> > LATITUDES
> >          Latitude of each measurement     1:185877  ...       
> > ...       ...
> > BEGINDATES
> >          Date of first measurement for e  1:1       ...       ...
> >  1:472
> > DATAINDEXES
> >          Data index in theoretical pass   1:185877  ...       
> > ...       ...
> > SLA      Sea Level Anomaly                1:1       1:185877  
> > ...       ...
> >
> >
> > I want to plot SLA over a small region say 50E-70E, 0-10N using go
> > polymark script. Here is what I used
> >
> > plot/vs/hlim=50:70/vlim=0:10 LONGITUDES,latitudes
> > go polymark polygon/hlim=50:70/vlim=0-10N/ov longitudes latitudes sla 
> > square
> >
> > then it gives me "  Too much polygon data to plot at once"
> >
> > No plot is generated. I use v5.8 Linux(g77) ferret version.
> >
> > Any help would be appreciated.
> >
> > Thanks,
> >
> > Prasad