masking

[Clark, Douglas B]

Sachin,

You can use the maskout function to do this kind of thing, e.g.
'd maskout(no2,india_mask)'

but you first need to create a variable (india_mask in my example) that you can use to discriminate between points in India and the rest of your domain. If you don't have such a mask available, you'll have to create one, probably outside of GrADS (e.g. using FORTRAN).

See the GrADS website for details of maskout.

For example, your india_mask variable would have value 1 over India and some value <0 at all other locations. Maskout needs a field that is <0 at the points to be excluded.

Doug


>> -----Original Message-----
>> From: GRADSUSR at LIST.CINECA.IT [mailto:GRADSUSR at LIST.CINECA.IT] On
>> Behalf Of Sachin Ghude
>> Sent: 27 October 2009 12:23
>> To: GRADSUSR at LIST.CINECA.IT
>> Subject: masking
>>
>> Hi,
>>
>> I want to plot tropospheric NO2 only over the Indian grid points (not
>> Nepal, Pakistan
>> and BanglaDesh). Is there any such utility so that it will enable me
>> to plot data only
>> for  India girds in GRADs. ( my grid size is 0.25 x 0.25 degrees).
>>
>> please do the needful..
>>
>> bye..
>>
>> Sachin

--
This message (and any attachments) is for the recipient only. NERC
is subject to the Freedom of Information Act 2000 and the contents
of this email and any reply you make may be disclosed by NERC unless
it is exempt from release under the Act. Any material supplied to
NERC may be stored in an electronic records management system.