Re: [ferret_users] Spatial Correlation;

[James Orr <James.Orr@xxxxxxxxxxxx>]

Karnan,

If yoru data is no a rectilinear grid, such as coads, use the 'regressxy' go 
script contributed by Andreas Schmittner:

! Use the LET command to define new variables
! Define the variable P as your independent (X) variable
! Define the variable Q as your   dependent (Y) variable

go regressxy

! Results will be variables "SLOPE", "INTERCEP" and "RSQUARE"

Jim

On Tue, 8 Aug 2017, Manche Shivashankar wrote:

> Dear Karnan,
>
> I have seen your .nc file, the data is two dimensional.
> If you want to derive spatial correlation you need to have time series data. Using the time series data the correlation
> coefficients will be calculated.
> With two dimensional data sets you can only derive the scatter plot at the collocated points of the like wise parameters.
>
> Hope this will help you.
>
>
> Regards
> Shiva Shankar Manche
> Scientists-SC
> NRSC, Hyderabad.
>
>
> On Mon, Aug 7, 2017 at 4:27 PM, Karnan C <karnanc6@xxxxxxxxx> wrote:
>       Dear ferret users,
>
>       I tried to correlate chl data with sea surface height, for that I set
>       these two data sets in a common grid.
>
>       I followed the scripts mentioned in the page
>       "http://ferret.pmel.noaa.gov/Ferret/faq/correlations-and-variances";.
>       This method is working well for coads_climatology data.
>
>       use data coads_clim.nc
>       let p=sst
>       let q=airt
>       go variance
>       fill correl
>
>       But, not for my data. I can't understand the reason.
>
>
>       use data relate.nc
>       let p=ssh
>       let q=chl
>       go variance
>       fill correl
>
>       (output shows 'no valid data')
>       The sample data files attached here.
>       Kindly help me.
>       Thanks.
>
>
>       --
>       C. Karnan, CSIR - SRF
>       Ph. D Research Scholar
>       National Institute of Oceanography (CSIR)
>       Regional Centre, Dr Salim Ali Road
>       Kochi - 682 018.
>       India.
>       Mobile No. +91 9633032345; +91 9941811608

--
LSCE/IPSL, Laboratoire des Sciences du Climat et de l'Environnement
CEA-CNRS-UVSQ

LSCE/IPSL, CEA Saclay           http://www.ipsl.jussieu.fr/~jomce
Bat. 712 - Orme                 mailto:  James.Orr@xxxxxxxxxxxx
Point courrier 132
F-91191 Gif-sur-Yvette Cedex    Phone:   (33) (0)1 69 08 39 73
FRANCE                          Fax:     (33) (0)1 69 08 30 73