[ncl-talk] Wondering how to write this if statement

Fri Sep 8 02:59:13 MDT 2017

Good to know -- thank you.

On Fri, Sep 8, 2017 at 11:53 AM, Guido Cioni <guidocioni at gmail.com> wrote:

> Generally there are no rules for comparing arrays because that would be
> pretty arbitrary depending on the language. That's why the most direct way
> of comparing array to array is to loop every index. Of course, that's not
> efficient...
>
> But there are a few functions written in NCL to compare and work with
> arrays https://www.ncl.ucar.edu/Document/Functions/array_manip.shtml
>
> On 8. Sep 2017, at 10:40, Barry Lynn <barry.h.lynn at gmail.com> wrote:
>
> Hi:
>
> My apologies for not making that clear, but I thought it was obvious that
> the if statement was comparing array values.
>
> I am hoping there is a more direct way to do this comparison than doing a
> loop, index by index.
>
> Thank you helping to clarify the programming issues.  Much appreciated.
>
> Barry
>
>
>
> On Fri, Sep 8, 2017 at 11:32 AM, Marston Johnston <shejo284 at gmail.com>
> wrote:
>
>> Hi,
>>
>>
>>
>> One of the first rules of programming is to READ the error statement.
>>
>>
>>
>> In your case there is nothing wrong with the IF statement per se. The
>> problem is that you do not understand what you are asking the IF statement
>> to do. As you have written it, the IF statement needs a scalar (single
>> value) or a boolean logical (true or false) in order to get the correct
>> execution.
>>
>> You are obviously passing an array of the sorts to the if statement.
>>
>>
>>
>> When posting to NCL, it helps if you print out the meta data for the
>> variables you are having trouble with (printVarSummary).
>>
>> When checking the elements of an array you need to loop over the elements
>> 1 at a time – if that is what you are trying to do.
>>
>> It is difficult for us to know what you are trying to do without a good
>> explanation from you.
>>
>>
>>
>> /M
>>
>>
>>
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> Marston S. Ward, PhD
>>
>> Department of Earth Sciences
>>
>> University of Gothenburg, Sweden
>>
>> Email: marston.johnston at gu.se
>>
>> SkypeID: marston.johnston
>>
>> Phone: +46-31-7864901 <+46%2031%20786%2049%2001>
>>
>> Only the fruitful thing is true!
>>
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>>
>>
>>
>>
>> *From: *Barry Lynn <barry.h.lynn at gmail.com>
>> *Date: *Friday, 8 September 2017 at 10:01
>> *To: *Marston Johnston <shejo284 at gmail.com>
>> *Cc: *ncl-talk <ncl-talk at ucar.edu>
>> *Subject: *Re: [ncl-talk] Wondering how to write this if statement
>>
>>
>>
>> Hi:
>>
>>
>>
>> Thank you (but)...
>>
>>
>>
>> It doesn't -- is there another "trick" we're leaving out?
>>
>>
>>
>> I think there is another way to write it where you condition it, rathern
>> than use an if statement.
>>
>>
>>
>> fatal:Conditional statements (if and do while) require SCALAR logical
>> values, see all and any functions
>>
>> fatal:["Execute.c":8575]:Execute: Error occurred at or near line 41 in
>> file ./radar_2.ncl
>>
>>
>>
>> On Fri, Sep 8, 2017 at 10:35 AM, Marston Johnston <shejo284 at gmail.com>
>> wrote:
>>
>> As far as I can see that should work:
>> if(dbz.lt.0.0) then
>>
>> Dbz = dbz + 256.0
>>
>> end if
>>
>>
>>
>> /M
>>
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> Marston S. Ward, PhD
>>
>> Department of Earth Sciences
>>
>> University of Gothenburg, Sweden
>>
>> Email: marston.johnston at gu.se
>>
>> SkypeID: marston.johnston
>>
>> Phone: +46-31-7864901 <+46%2031%20786%2049%2001>
>>
>> Only the fruitful thing is true!
>>
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>>
>>
>>
>>
>> *From: *ncl-talk <ncl-talk-bounces at ucar.edu> on behalf of Barry Lynn <
>> barry.h.lynn at gmail.com>
>> *Date: *Friday, 8 September 2017 at 09:33
>> *To: *ncl-talk <ncl-talk at ucar.edu>
>> *Subject: *[ncl-talk] Wondering how to write this if statement
>>
>>
>>
>> Hi:
>>
>>
>>
>> I am wondering how to properly write this if statement in NCL language.
>>
>>
>>
>>   if (dbz.lt.0)then
>>
>>    dbz = dbz + 256
>>
>>   end if
>>
>>
>>
>> --
>>
>> Barry H. Lynn, Ph.D
>>
>> Senior Lecturer,
>>
>> The Institute of the Earth Science,
>> The Hebrew University of Jerusalem,
>> Givat Ram, Jerusalem 91904, Israel
>>
>> Tel: 972 547 231 170
>> Fax: (972)-25662581
>>
>>
>>
>> C.E.O, Weather It Is, LTD
>> Weather and Climate Focus
>> http://weather-it-is.com
>> Jerusalem, Israel
>> Local: 02 930 9525
>> Cell: 054 7 231 170
>> Int-IS: x972 2 930 9525
>> US 914 432 3108 <(914)%20432-3108>
>>
>> _______________________________________________ ncl-talk mailing list
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>>
>>
>>
>>
>>
>> --
>>
>> Barry H. Lynn, Ph.D
>>
>> Senior Lecturer,
>>
>> The Institute of the Earth Science,
>> The Hebrew University of Jerusalem,
>> Givat Ram, Jerusalem 91904, Israel
>>
>> Tel: 972 547 231 170
>> Fax: (972)-25662581
>>
>>
>>
>> C.E.O, Weather It Is, LTD
>> Weather and Climate Focus
>> http://weather-it-is.com
>> Jerusalem, Israel
>> Local: 02 930 9525
>> Cell: 054 7 231 170
>> Int-IS: x972 2 930 9525
>> US 914 432 3108 <(914)%20432-3108>
>>
>
>
>
> --
> Barry H. Lynn, Ph.D
> Senior Lecturer,
> The Institute of the Earth Science,
> The Hebrew University of Jerusalem,
> Givat Ram, Jerusalem 91904, Israel
> Tel: 972 547 231 170
> Fax: (972)-25662581
>
> C.E.O, Weather It Is, LTD
> Weather and Climate Focus
> http://weather-it-is.com
> Jerusalem, Israel
> Local: 02 930 9525
> Cell: 054 7 231 170
> Int-IS: x972 2 930 9525
> US 914 432 3108 <(914)%20432-3108>
> _______________________________________________
> ncl-talk mailing list
> ncl-talk at ucar.edu
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
>
>
> Guido Cioni
> http://guidocioni.altervista.org
>
>

-- 
Barry H. Lynn, Ph.D
Senior Lecturer,
The Institute of the Earth Science,
The Hebrew University of Jerusalem,
Givat Ram, Jerusalem 91904, Israel
Tel: 972 547 231 170
Fax: (972)-25662581

C.E.O, Weather It Is, LTD
Weather and Climate Focus
http://weather-it-is.com
Jerusalem, Israel
Local: 02 930 9525
Cell: 054 7 231 170
Int-IS: x972 2 930 9525
US 914 432 3108
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