Re: Getting number of variables

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi Sudheer,
Does @NGD and @NBD give you what you need?  Even when you have
read your data onto the default abstract axis,  LET N = var[I=@NGD]  
will set
the value of N to the number of valid points.

Sudheer Joseph wrote:

> Dear Jaison,
>                              I agree that it is good to define the 
> axis properly and read the variable in to it , But I am doing a batch 
> job where in, there is a list of data going to ferret and getting data 
> of corresponding locations form a netcdf file and do some calculation 
> involving both. here it is hard to define the axis since it varies its 
> size with every file and it depends on the number of common point s in 
> both datasets.
>
> thanks,
> Sudheer
>
>
> ***************************************
> Dr. Sudheer Joseph
> Indian National Centre for Ocean Information Services
> Gajularamaram B.O., IDA Jeedeemetla S.O.
> Via Pragathi Nagar, Kukatpally, Hyderabad
> Pin:5000 55
> Tel:+91-40-23044600(R)
> Tel:+91-40-9440832534(Mobile)
> Tel:+91-40-25503595(O)
> Fax:+91-40-25503596(O)
> E-mail:sjo@rediffmail.com;
> callsjo@yahoo.com;
> sjo@incois.gov.in.
> Web- http://oppamthadathil.tripod.com
> ***************************************
>
>
>
> > From: Jaison Kurian <jaison@caos.iisc.ernet.in>
> > To: ferret_users@noaa.gov
> > CC: Sudheer Joseph <sjo_cma@hotmail.com>
> > Subject: Re: Getting number of variables
> > Date: Tue, 7 Dec 2004 01:26:15 +0530 (IST)
> >
> > Hi Sudheer,
> >              I always prefer to read the data from ASCII file to a
> > properly defined grid instead of depending on the default way. If
> > you are doing it in this way then you can use the variable just like
> > one in a good NetCDF file. IF you are interested please have a look at
> > Ferret manual : Ch2 Sec5.1.  Reading ASCII files , and
> > Ref Sec4.2.  DEFINE AXIS.
> >
> >  Here is an example. If you have any doubts please let me know.
> >
> >  Hope this helps
> >
> >  With Regards
> >
> >  Jaison
> >
> > !-------------example.dat--------------
> > 29.50
> > 28.95
> > -999.99
> > 27.30
> > 28.60
> > 29.40
> > -999.99
> > 29.50
> > 28.60
> > 28.30
> > !-----------example.jnl---------------
> > ! Let us read the data in example.dat to a proper grid/axis.
> > !   we have 10 data values, so define an axis with 10 points.
> > !   define a grid only with this axis, and read the data onto this
> > !   grid.
> >
> >     DEFINE AXIS/x=1:10:1  xfile
> >     DEFINE GRID/x=xfile   gfile
> >
> >     FILE/grid=gfile/var=var1 num_of_points.dat
> >     set var/bad=-999.99 var1    ! set only the missing value..OR
> >     ! set var/bad=-999.99/title=""Temperature"/units="^oC" var1
> >     list var1
> >
> >     let vardev      = var1 - var1[i=@AVE]
> >     let vardevsq    = vardev^2
> >     let sumsqvardev = vardevsq[i=@sum]
> >
> > ! now ..to get the number of valid data points use @NGD..simple one
> > ! please note that here `var1,return=isize` - var1[x=@nbd] will also
> > ! return accurate value(8).
> >
> >     let good_pts    = var1[i=@NGD]
> >     list good_pts
> >
> >     let myoutput = sumsqvardev/good_pts
> >     list myoutput
> >
> > !-----------------end of example.jnl--------------------------
> >
> > On Mon, 6 Dec 2004, Sudheer Joseph wrote:
> >
> > > Dear Users
> > >                         I would like to get  variance calculted by 
> > defining
> > > file/var=var1  vardat.dat
> > > ! The axis under consideration is irregular
> > > let vardev=var1-var1[x=@ave]
> > > let vardevsq= vardev^2
> > > let sumsqvardev=vardevsq[x=@sum]
> > > and then to devide it by the number of points i wanted to get the 
> > actual
> > > number of points
> > > I tried using the `var1,return=size` - var1[x=@nbd] but is not 
> > working since
> > > the size of axis is not limited
> > > it gives a return of 20000+ value which is the default ferret axis 
> > size
> > > I would like to get the actual number of variables to devide the 
> > sum of
> > > suired deviations.
> > > I realise that there is a function @var existing in ferret but 
> > wanted to use
> > > the manual calculation for some cross checking
> > > can any one help
> > > thanks,
> > > sudheer
> > >
> > >
> > > ***************************************
> > > Dr. Sudheer Joseph
> > > Indian National Centre for Ocean Information Services
> > > Gajularamaram B.O., IDA Jeedeemetla S.O.
> > > Via Pragathi Nagar, Kukatpally, Hyderabad
> > > Pin:5000 55
> > > Tel:+91-40-23044600(R)
> > > Tel:+91-40-9440832534(Mobile)
> > > Tel:+91-40-25503595(O)
> > > Fax:+91-40-25503596(O)
> > > E-mail:sjo@rediffmail.com;
> > > callsjo@yahoo.com;
> > > sjo@incois.gov.in.
> > > Web- http://oppamthadathil.tripod.com
> > > ***************************************
> > >
> > > _________________________________________________________________
> > > All the news that matters. Just the way you like it.
> > > http://www.msn.co.in/News/ Only at MSN News!
> > >
> >
> > --
> > ___________________________________________________
> >
> >     Jaison Kurian
> >     Centre for Atmospheric and Oceanic Sciences
> >     Indian Institute of Science
> >     B A N G A L O R E   560 012
> >     Ph: +91-80-3942505
> >         +91-80-3600450
> >     Fax:+91-80-3600865
> > ___________________________________________________
> _________________________________________________________________
> Pep up your screen! Kickstart your day! 
> http://www.msn.co.in/Cinema/screensaver/ Get these vibrant screensavers!