mixed layer depth using no standard level data

[Namba Takaya <takayanamba@xxxxxxxxxxx>]

Dear sir.

I want to calculate the mixed layer depth from the data (file name 
sample.txt) below. 

The data have randam depth (not the standard depth).

temperature      salinity      depth
27.96            33.5          4.1
27.88            33.5          10.9
27.84            33.7          20.4
27.78            33.8          29.4
27.66            33.9          42.5
27.60            34.2          50.2
27.31            34.6          59.8
27.35            34.6          70.4
27.36            34.5          77.3

I want to define the mixed layer depth by density difference from the 
surface.
If I define the mixed layer depth, 0.3 different in density from the 
surface, how I can calculate the mixed layer depth?

What I did is below

file /var="tem,sal,dep" sample.txt
let rho=rho_un(sal,tem,dep)
let diffr=rho-rho[i=1]-0.3
let mldr=diffr[dep=@loc:0]   !!! this is problem.
list mldr

but I could not make it.

Could you tell me why or could you tell me some other ways to do it?

Thank you in advance.

Takaya Namba


_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.