multi-year monthly mean standard deviation

[Simon Krichak]

Dear all,

My script looks better now (after the suggested by Laura correction) :

'open  ../CRU-DATA/GRADS:1951-2000.pre.ctl '
'open  ../CRU-DATA/GRADS:1951-2000.tmp.ctl '
'set x 1'
'set y 1'
'set t 1 12'
'set tlsupp year'
'define ztemp=ave(aave(tmp.2,lon=36,lon=54,lat=51,lat=65),t+396,t=528,12)'
'define zprec=ave(aave(pre,lon=36,lon=54,lat=51,lat=65),t+396,t=528,12)/30'
'd
tloop(sqrt(ave(aave(pow(ztemp-tmp.2,2),lon=36,lon=54,lat=51,lat=65),t+396,t=528,12)))'
'd
tloop(sqrt(ave(aave(pow(zprec-pre,2),lon=36,lon=54,lat=51,lat=65),t+396,t=528,12)))'


But still doesn't work properly - please see the result below.
Thanks,
                     Simon Krichak

Grid Analysis and Display System (GrADS) Version 1.9b4
Copyright (c) 1988-2005 by Brian Doty and IGES
Center for Ocean-Land-Atmosphere Studies (COLA)
Institute for Global Environment and Society (IGES)
GrADS comes with ABSOLUTELY NO WARRANTY
See file COPYRIGHT for more information

Config: v1.9b4 32-bit little-endian readline sdf/xdf hdf-sds netcdf lats
printim

Issue 'q config' command for more information.

Landscape mode? (no for portrait):
GX Package Initialization: Size = 11 8.5
ga-> stand-deviation.gs
Cannot plot data - all undefined values
Cannot plot data - all undefined values
ga->

----- Original Message -----
From: "LAURA FEUDALE" <feudale at ICTP.IT>
To: <GRADSUSR at LIST.CINECA.IT>
Sent: Tuesday, April 03, 2007 11:42 AM
Subject: Re: multi-year monthly mean standard deviation


> Dear Simon,
> the aave function doesn't work when time is a varying dimension. In this
> case you should use the "tloop" function.
> So try adding the tloop function in this way:
>
> .....
> 'd
> tloop(sqrt(ave(aave(pow(ztemp-tmp.2,2),lon=36,lon=54,lat=51,lat=65),t+396,t=528,12)))'
> 'd
> tloop(sqrt(ave(aave(pow(zprec-pre,2),lon=36,lon=54,lat=51,lat=65),t+396,t=528,12)))'
>
> Regards,
>
> -- Laura
>
> ----------------------------------------------------------------------
>  Laura Feudale, Ph.D. (Climate Dynamics, George Mason University/COLA)
> *Current Affiliation:            Earth System Physics Section
>  The Abdus Salam International Centre for Theoretical Physics
>                         Trieste, ITALY
> ----------------------------------------------------------------------
>
>
>
> On Tue, 3 Apr 2007, Simon Krichak wrote:
>
>> Dear Experts,
>>
>>  I am trying to calculate mean multiyear standard deviations from
>>  monthly mean data on temperature and precip.
>>
>> To do it I apply the following script:
>>
>> 'open  ../CRU-DATA/GRADS:1951-2000.pre.ctl '
>> 'open  ../CRU-DATA/GRADS:1951-2000.tmp.ctl '
>> 'set x 1'
>> 'set y 1'
>> 'set t 1 12'
>> 'set tlsupp year'
>> 'define
>> ztemp=ave(aave(tmp.2,lon=36,lon=54,lat=51,lat=65),t+396,t=528,12)'
>> 'define
>> zprec=ave(aave(pre,lon=36,lon=54,lat=51,lat=65),t+396,t=528,12)/30'
>> 'd
>> sqrt(ave(aave(pow(ztemp-tmp.2,2),lon=36,lon=54,lat=51,lat=65),t+396,t=528,12))'
>> 'd
>> sqrt(ave(aave(pow(zprec-pre,2),lon=36,lon=54,lat=51,lat=65),t+396,t=528,12))'
>>
>> And obtain the following diagnostics:
>>
>> ga-> stand-deviation.gs
>> Syntax Error:  Invalid dimension expression
>>  Cannot use an offset value with a varying dimension
>>  Varying dimension = 3
>> Error from AVE:  1st dimension expression invalid
>> Operation Error:  Error from ave function
>>  Operation Error:  Error from sqrt function
>>  Error ocurred at column 1
>>  DISPLAY error:  Invalid expression
>> Expression =
>> sqrt(ave(aave(pow(ztemp-tmp.2,2),lon=36,lon=54,lat=51,lat=65),t+396,t=528,12))
>> Syntax Error:  Invalid dimension expression
>> Cannot use an offset value with a varying dimension
>> Varying dimension = 3
>> Error from AVE:  1st dimension expression invalid
>> Operation Error:  Error from ave function
>> Operation Error:  Error from sqrt function
>>  Error ocurred at column 1
>>  DISPLAY error:  Invalid expression
>>  Expression =
>> sqrt(ave(aave(pow(zprec-pre,2),lon=36,lon=54,lat=51,lat=65),t+396,t=528,12))
>>
>>
>> I do not understand my mistake unfortunately.
>> Please kindly let me know your recommendations.
>>
>> Thanks.
>>                    Simon Krichak
>>
>>
>