[gradsusr] define a simple scalar

Lisa Welp-Smith lwelp at ucsd.edu
Mon Aug 1 14:57:28 EDT 2011


Never mind my last message.  I realize now that ltrend exports the trend 
as well as the slope.  That's all I need.

Lisa

On 8/1/11 9:56 AM, Lisa Welp-Smith wrote:
> Dear Joey,
>
> I see how you suggest defining the multiple variables, but I don't see 
> how this gets me any closer to creating detrended observations?
>
> I was aiming for:
> detrend = obs - trend
> where: trend(t) = slope*t, over t=1 -> t=20
>
> Given your suggestion, I can imagine creating a loop to display:
> d obs(t) - slope*t
>
> But without writing those values to a variable, e.g. detrend, I don't 
> see how I can use the detrended observations for any additional 
> calculations (for example, in tcorr).
>
> Thank you,
> Lisa
>
> ------------------------------ Date: Sat, 30 Jul 2011 15:31:13 -0500 
> From: Joey Woodson <instantweathermaps at gmail.com> Subject: Re: 
> [gradsusr] define a simple scalar To: GrADS Users Forum 
> <gradsusr at gradsusr.org> Message-ID: 
> <CAJv4EQoa6wPtWB-f+F4vMsBA6Yh1VaoFx+M7UrTzw7SuxAZbMw at mail.gmail.com> 
> Content-Type: text/plain; charset="iso-8859-1" set t 1 variable1 = 
> const(kanto, 1, -a) set t 2 variable2 = const(kanto, 2, -a) where 
> "kanto" is any variable in the file. AFAIK there is no way to define 
> different timesteps of the same variable in different ways. A for loop 
> can take care of the trouble involved with using multiple variables. 
> On Sat, Jul 30, 2011 at 2:00 PM, Lisa Welp-Smith <lwelp at ucsd.edu> wrote:
>
>> >  Hello,
>> >
>> >  I'm having a problem with what I'm sure is a simple task.  I want to
>> >  define a scalar to convert a slope (i.e. units/year) into a trend 
>> line
>> >  over several years.  I'm using this to detrend a time series.
>> >  Basically I just need to construct a simple scalar (i.e. variable 
>> = 1 2
>> >  3 4 5...) or a variable that equals the year of each entry of my 
>> dataset
>> >  (i.e. variable = 1991 1992 1993 1994 1995...) that I can multiply 
>> by my
>> >  slope values.  I can use tloop to create the right dimensions 
>> (variable
>> >  = 1 1 1 1 1...) but I can't seem to get the values to increase for 
>> each
>> >  time step.
>> >
>> >  Imagine I could either create a datafile manually and read it in or
>> >  somehow extract the year information from the existing dataset into a
>> >  user defined variable.
>> >
>> >  Is there an equivalent of 'define variable(t=2) = 2'?  I know this
>> >  syntax is wrong.
>> >
>> >  Any advice would be appreciated.
>> >
>> >  Lisa
>> >
>> >  --
>> >  Lisa Welp-Smith
>> >  Carbon Dioxide Research Group
>> >  Scripps Institution of Oceanography
>> >
>> >
>> >  _______________________________________________
>> >  gradsusr mailing list
>> >  gradsusr at gradsusr.org
>> >  http://gradsusr.org/mailman/listinfo/gradsusr
>> >
>


-- 
Lisa Welp-Smith
Carbon Dioxide Research Group
Scripps Institution of Oceanography





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