Re: [ferret_users] samplet_date

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

Hi all,
I have a fix for the SAMPLET_DATE function which will be in the next Ferret release. Carol is quite right that if you give the function the day and time of a time coordinate, it should return exactly the same result as the LIST command.

For her purpose of listing the data at a collection of times, the SAMPLEL function can be used, expressing the  collection of times as a set of L index values.

Ansley

On 3/30/2012 10:09 AM, Ansley Manke wrote:

Hi Carol,
Yes, they should return the same thing for hour 0 on your daily time axis.  I think Russ is on to the right idea, but in fact I think that the calculation needs even more of a fix to compute the correct result.  Please stand by.

Ansley

On 3/29/2012 4:26 PM, Carol Ladd wrote:

I am trying to extract certain dates from a time series using the samplet_date function but it is not returning what I would expect.  It looks like the function is interpolating between the dates and I don’t know if it is a problem with the samplet_date function or a problem with how I have my time axis defined.  I have attached my time series to use as an example:

 

yes? use urot2.nc

yes? sh d

yes? list/t=9-sep-1999 urot2

             VARIABLE : U_ROT[GT=TQSCT@ASN]

             FILENAME : urot2.nc

             Z (m)    : 0

             TIME     : 09-SEP-1999 00:00

         -13.24

 

yes? list SAMPLET_DATE(UROT2,1999,9,9,0,0,0)

             VARIABLE : SAMPLET_DATE(UROT2[D=urot2],1999,9,9,0,0,0)

             Z (m)    : 0

             T        : 1

         -12.92

 

Why are they not the same?

 

Thanks.

Carol

 

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Carol Ladd

Oceanographer

 

NOAA/PMEL

7600 Sand Point Way

Building 3     

Seattle, WA                   

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Phone: (206) 526-6024

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Email: carol.ladd@xxxxxxxx

 

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