RE: How to do time lag correlation in ferret?

[Mark Williams <mark.williams@xxxxxxxxxx>]

Hello Yang

This is how I do lag and lead correlations.

Use the go file variance.jnl

! Define your variables to be correlated
let p = sst
let q = wind ! (or what ever the variable names are)
go variance
contour correl ! (contours the correlations)

This will give simultaneous correlations.  To get lag and leads use the 
transformation @shf when defining p or q.  For example:

Let q = wind[L=@shf:5]

The 6th time step in the original time series of q now becomes the first 
etc.  Thus p (sst) leads q (wind) by 5 when you do the correlation.  You 
can use negative numbers also.



Mark Williams
Supervising Meteorologist
Ph 61 3 9669 4902


----------
From:  Yang Haijun [SMTP:navyang@tuna.meteor.wisc.edu]
Sent:  Wednesday, 05 January 2000 03:22
To:  ferret_users@ferret.wrc.noaa.gov
Subject:  How to do time lag correlation in ferret?

Hi, Dear Ferreters,

Have anyone done time lag correlation between two long term series data 
set?
For example, I have two data SST and WIND with 50 years, I want to get 
correlation coefficient
between SST and 5-year-later WIND, how can I do that?
Any suggestions are highly appreciated.

Haijun Yang