[gradsusr] define variable independent of time

Jeffrey Duda jdduda at iastate.edu
Mon Sep 12 12:16:59 EDT 2011


Bernd,
To help me understand, could you provide a simple example?

Jeff

On Mon, Sep 12, 2011 at 3:03 AM, Becker, Bernd <
bernd.becker at metoffice.gov.uk> wrote:

> **
> Jeff,
>
> That is is the really hard part.
> Each item fx and obs describes a chunk of a time series.
> One would have to manually calculate the start and end dates
> with respect to the reference dfile.
>
> If only (and I think Mike explained it a long time ago, and I cannot find
> the
> email) one could
> set file 1
> set t 2 34
> define whatever
> set dfile 2
> set t 6 39
> define theother
>
> and happily combine whatever with theother.
>
> Think about multimodel ensemble hindcast analysis, trying to composit
> observed phenomena with modelled phenomena that simply
> don't happen simultaneously.
>
> All the best,
> Bernd.
>
>
>
> --
> Bernd Becker   Climate Impacts Product Development
> Met Office Hadley Centre    FitzRoy Road  Exeter   Devon EX1 3PB  United
> Kingdom
> Tel.: +44 (0) 1392 884511 Fax: +44 (0)870 900 5050
> E-mail:bernd.becker at metoffice.gov.uk -
> http://www.metoffice.gov.uk/research/our-scientists/seasonal-to-decadal/bernd-becker
> http://www.metoffice.gov.uk/news/releases/archive/2011/weather-game
>
>
>  ------------------------------
> *From:* gradsusr-bounces at gradsusr.org [mailto:
> gradsusr-bounces at gradsusr.org] *On Behalf Of *Jeffrey Duda
> *Sent:* 10 September 2011 18:41
>
> *To:* GrADS Users Forum
> *Subject:* Re: [gradsusr] define variable independent of time
>
> You can reference the time of a variable when you use it in a statement.
> For example, you could do
>
> 'd var.2(time=12Z01JAN1996) - var.3(time=18Z13AUG2010)'
>
> This should help you do what you want to do.
>
> Jeff Duda
>
> On Sat, Sep 10, 2011 at 3:30 AM, Becker, Bernd <
> bernd.becker at metoffice.gov.uk> wrote:
>
>> **
>> Thanks Arlindo,
>>
>> That would be nice for single numbers.
>>
>> It as one notch more elaborate:
>>
>>   'set dfile 2'
>>   'set t 2  33'
>>   'define obs     = 'var'.2'
>>  'set dfile 3'
>>   'set t 2  33'
>>   'define fx     = 'var'.3'
>> file 2 and 3 have different time frames.
>>
>> d fx-obs
>>
>> fails.
>> And it would be a real bummer to have to calculate the times from one file
>> relative
>> to the other file.
>>
>> Compositing in this way would be really hard.
>>
>> Enjoy the weekend!
>> Bernd.
>>
>>
>> --
>> Bernd Becker   Climate Impacts Product Development
>> Met Office Hadley Centre    FitzRoy Road  Exeter   Devon EX1 3PB  United
>> Kingdom
>> Tel.: +44 (0) 1392 884511 Fax: +44 (0)870 900 5050
>> E-mail:bernd.becker at metoffice.gov.uk -
>> http://www.metoffice.gov.uk/research/our-scientists/seasonal-to-decadal/bernd-becker
>> http://www.metoffice.gov.uk/news/releases/archive/2011/weather-game
>>
>>
>>  ------------------------------
>> *From:* gradsusr-bounces at gradsusr.org [mailto:
>> gradsusr-bounces at gradsusr.org] *On Behalf Of *Arlindo da Silva
>> *Sent:* 09 September 2011 17:40
>> *To:* GrADS Users Forum
>> *Subject:* Re: [gradsusr] define variable independent of time
>>
>> On Fri, Sep 9, 2011 at 12:05 PM, Becker, Bernd <
>> bernd.becker at metoffice.gov.uk> wrote:
>>
>>>
>>> Simple question,
>>> complicated answer:
>>>
>>> I would like to composite stuff from several  files.
>>>
>>> Each file has its own time and date info in its own .ctl file.
>>>
>>> How can I add elements from different such files?
>>>
>>> How can I break away from the strict treatment of the time dimension in
>>> grads?
>>>
>>> open file1.ctl
>>> define a=ave(b,t=1,t=34)
>>> close 1
>>> open file2.ctl
>>> define c= ave(b,t=3,t=9)
>>> close 2
>>> etc.
>>>
>>> d a+c
>>> Cannot contour grid - all undefined values
>>>
>>>
>> Try:
>>
>> d a(t=1)+c(t=1)
>>
>>
>> --
>> Arlindo da Silva
>> dasilva at alum.mit.edu
>>
>> _______________________________________________
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>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr
>>
>>
>
>
> --
> Jeff Duda
> Iowa State University
> Meteorology Graduate Student
> www.meteor.iastate.edu/~jdduda <http://www.meteor.iastate.edu/%7Ejdduda>
>
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>
>


-- 
Jeff Duda
Iowa State University
Meteorology Graduate Student
www.meteor.iastate.edu/~jdduda <http://www.meteor.iastate.edu/%7Ejdduda>
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