lines from the corner

[Matthias Munnich]

Hi Adam:

A while ago I  patched GrADS to replace NaN's, Inf and -Inf internally
by  missing value. I had forwarded a patch to COLA for inclusion in the
main distribution.

I thought it was put in. But now I remember that Brian was hesitant as
it uses some bit-pattern trickery around IEEE binary numbers to make it
work for big- and little-endian numbers on both 32 and 64 bit machines.

I can put together a patch and send it to you if you like.  Getting rid
of NaN's can be awkward as  IEEE standards require tests  like "x==NaN"
to return NaN no matter what.

Matt


Adam Sobel wrote:

> Diane,
>
> thanks a lot.  You are right.  The file has NaNs in it.  Looking over
> old posts on this
> problem I was hoping to find a way to treat NaN as a missing value
> without having to
> actually go and rewrite the file.  So far it looks like this is not
> doable, but if I'm wrong
> maybe someone could let me know how to do that.
>
> thanks
> Adam
>
> Diane Stokes wrote:
>
>> Adam,
>>
>> Looking closely at your plot, I wonder if you have bad values at some
>> coastal points.
>>
>> I suggest you zoom in on one of those areas and use gxout grid or
>> print to check that you have good values or the correct "missing"
>> value at all points.
>>
>> If that's not the cause, what version of grads are you running?  A
>> user here encountered similar problems (with presumably good data) but
>> his plot was fine when he switched to version 1.9b4.
>>
>>    Diane
>>
>>
>> Adam Sobel wrote:
>>
>>> Hello,
>>>
>>> I have a data file (netcdf, opens fine with sdfopen) which when I try
>>> to make a contour plot, gives me straight lines from the corner which
>>> cover up the plot, which otherwise would look fine. Example attached.
>>> I suspect it has something to do with the fact that this data is all
>>> missing over the land (it is an ocean-only data set) but other than
>>> that can't see what's wrong. Changing the contour interval doesn't
>>> help. I found another post on this behavior in the archive but no one
>>> seems to have answered that one (a few years ago). Any insight
>>> appreciated.
>>>
>>> thanks
>>> Adam
>>>
>>> --
>>> Adam H. Sobel
>>> Department of Applied Physics and Applied Mathematics
>>> Department of Earth and Environmental Sciences
>>> Columbia University
>>> 500 W. 120th Street, Room 217
>>> New York, NY 10027
>>> tel: 212-854-6587
>>> fax: 212-854-8257
>>> e-mail: ahs129 at columbia.edu
>>> web: http://www.columbia.edu/~ahs129/home.html
>>>
>>>
>>> ------------------------------------------------------------------------
>>>
>>>
>>
>
> --
> Adam H. Sobel
> Department of Applied Physics and Applied Mathematics
> Department of Earth and Environmental Sciences
> Columbia University
> 500 W. 120th Street, Room 217
> New York, NY 10027
> tel: 212-854-6587
> fax: 212-854-8257
> e-mail: ahs129 at columbia.edu
> web: http://www.columbia.edu/~ahs129/home.html