Re: [ferret_users] Correlation between one point and 2D spatial data

["'Iskhaq Iskandar' via _OAR PMEL Ferret Users" <ferret_users@xxxxxxxx>]

Hi Chinu and Shuder,

Thank you for help.
Cheers, iskhaq
--------------------------------------------
On Fri, 1/15/16, chinnu sachi <chinnu.sachi7@xxxxxxxxx> wrote:

 Subject: Re: [ferret_users] Correlation between one point and 2D spatial data
 To: "Iskhaq Iskandar" <iskhaq@xxxxxxxxx>
 Cc: "ferret_users@xxxxxxxx" <ferret_users@xxxxxxxx>
 Date: Friday, January 15, 2016, 7:09 PM
 
 Hello
 Sir,
               
 Check the time axis.And specify the time axis while
 assiagning P and Q. 
 Here your
 data is daily,so according to the time axis there will be
 504 points.Also you didn't mention the location,so lets
 just say current at 90E and sla at the equatorial indian
 ocean.After specifying the all axis then it will look like
 the following,then go for the correlation. 
 
 use daily-current.nc
 
 use daily-ssh.nc
 set mem/size=600
 
 let p = u[d=1,l=1:504,x=90E,y=0]
 let q =
 sla[d=2,l=1:504,x=40E:120E,y=10s:10n] 
 go variance
 shade
 correl
 
 can data/a
 
 can var/a
 
 can mem
 
 Hope it will
 solve your error.
 
 -- 
 Regards,
 Chinnu
 Sachidanandan
 Physical Oceanography
 Division
 National Institute of
 Oceanography
 csachidanandan@xxxxxxx
 
 
 On Fri, Jan 15, 2016 at
 12:37 PM, 'Iskhaq Iskandar' via _OAR PMEL Ferret
 Users <ferret_users@xxxxxxxx>
 wrote:
 Dear Ferret users,
 
 
 
 I am trying to compute a correlation between an observed
 current at one location (1D data: varies in time only) with
 SSH of a basin-wide region (2D data in x,y and time).
 
 
 
 What I did is something like this:
 
 
 
 -------------------
 
 use daily-ssh.nc
 
 use daily-current.nc
 
 set mem/size=600
 
 
 
 def axis/t=1-jan-2009:19-May-2010:1/unit=days tday
 
 let ssh = sla[d=1, gt=tday]
 
 let uvel = u[d=2, gt=tday]
 
 
 
 let p = uvel
 
 let q = ssh
 
 go variance
 
 
 
 shade correl
 
 !
 
 can data/a
 
 can var/a
 
 can mem
 
 --------------------
 
 
 
 But I got an error like:
 
 
 
 -------
 
  *** NOTE: Ambiguous coordinates on X axis: P*Q-P*Q + 1
 
  *** NOTE: Ambiguous coordinates on X axis: Q*MASK_PQ
 
  *** NOTE: Ambiguous coordinates on X axis: COVAR /
 (P_VAR_MASK*Q_VAR_MASK)^.5
 
  *** NOTE: Ambiguous coordinates on X axis: P_DEV_MASK *
 Q_DEV_MASK
 
  **ERROR: dimensions improperly specified: must be a 2D
 region
 
 --------
 
 
 
 If I change between P and Q, I will get an error like:
 
 
 
 --------
 
 *** NOTE: Ambiguous coordinates on X axis: P*Q-P*Q + 1
 
  *** NOTE: Ambiguous coordinates on X axis: Q*MASK_PQ
 
  *** NOTE: Ambiguous coordinates on X axis: COVAR /
 (P_VAR_MASK*Q_VAR_MASK)^.5
 
  *** NOTE: Ambiguous coordinates on X axis: P_DEV_MASK *
 Q_DEV_MASK
 
  **ERROR: inconsistent sizes of data regions: X axis
 
           Q has 3 points (I=0:2)
 
           expression has 301 points (I=001:301)
 
 ---------
 
 
 
 Do you have any suggestion?
 
 Thank you for help.
 
 
 
 Best regards,
 
 Iskhaq
 
 
 
 
 
 
 
 ----------------------------------------------------------------
 Dr. Iskhaq Iskandar Jurusan Fisika, Fakultas MIPA
 Universitas Sriwijaya Kampus Inderalaya, Ogan Ilir (OI)
 Sumatra Selatan, 30662 INDONESIA Phone: +62 (711) 580743
 Fax: +62 (711) 580268 E-mail: iskhaq.iskandar@xxxxxxxxx
 http://iskhaq.wordpress.com/
 ----------------------------------------------------------------