Thank you Andrew.
The where function is very much useful.
Thanks a lot for your quick reply.
On 29 March 2011 18:39, Andrew Dawson <dawson@atm.ox.ac.uk> wrote:
> In the documentation for the 'where' function there is actually an example
> of this:
>
> http://www.ncl.ucar.edu/Document/Functions/Built-in/where.shtml
>
> Look in the 'Description' section for the part labelled 'Caveat:'.
> Basically you need to set pdfobsr to a missing value where it is zero and
> then do the division, preventing a divide by zero error.
>
> Hope that helps,
> Andrew
>
> On 29 March 2011 14:00, gibies george <gibies@tropmet.res.in> wrote:
>
>> Here is some part of my ncl script where pdfobsr, pdffcst, pdfratio and lnpdfrat
>> are multi dimensional variables.
>>
>> pdfobsr = pdf_time(ssnobsr)
>> pdffcst = pdf_time(ssnfcst)
>> pdfratio = pdffcst/pdfobsr
>> lnpdfrat = log(pdfratio)
>>
>> But (as everybody knows), It will cause problem at some point where pdfobsr
>> (denominator) is zero.
>>
>> Can anybody suggest a way to rewrite this script in order to avoid the
>> division by zero ?
>>
>> Thanking you in advance.
>> ____________
>>
>> Note : pdf_time() used above is my function to find the probability
>> density along time dimension at each grid point.
>>
>> --
>> *Gibies George, CSIR-RF,*
>> *Monsoon Seasonal Prediction Group,
>> Climate and Global Modelling Division,
>> Indian Institute of Tropical Meteorology,
>> Dr. Homi Bhabha Road,
>> NCL (P. O.), Pashan,
>> Pune 411008, India.*
>>
>> *http://sites.google.com/site/gibiesge/*
>>
>> Please Think about the environment. Save paper; Save Trees; and don't
>> print this e-mail unless it is necessary.
>>
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>
-- *Gibies George, CSIR-RF,* *Monsoon Seasonal Prediction Group, Climate and Global Modelling Division, Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, NCL (P. O.), Pashan, Pune 411008, India.* *http://sites.google.com/site/gibiesge/* Please Think about the environment. Save paper; Save Trees; and don't print this e-mail unless it is necessary.
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Received on Tue Mar 29 08:48:46 2011
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