[ncl-talk] Options in eofunc

[Dennis Shea]

???    There is no Example 7

http://www.ncl.ucar.edu/Applications/eof.shtml

re: "I am not 100% sure what the third option (80.) means in this case"

I am not sure either!

===
That said, the last argument is prototypes as 'logical

function eofunc (
		data    : numeric,
		neval   : integer,
		optEOF  : logical   <======
	)


If the function is invoked as:
       $ evec= eofunc(ptw,neval,80.)

You should have received the following message

warning:Argument 2 of the current function or procedure was coerced to the
appropriate type and thus will not change if the function or procedure
modifies its value

The correct usage is:

optEOF       = True
optEOF at pcrit = 80
evec= eofunc(ptw,neval,optEOF)

==============================

Deep Background: NCL actually coerces (converts) the '80.' to a True.
However, since there are no optional arguments associated with this coerced
argument, it would operate as if the 'optEOF-False'



On Fri, Jan 20, 2017 at 7:52 AM, Yohei Takano <yohei.takano at mpimet.mpg.de>
wrote:

> Dear NCL users,
>
>   I have a question on "eofunc".
> The NCL website tells me that eofunc has three input (options)
>
>   function eofunc(
>                 data    : numeric,
>                 neval   : integer,
>                 optEOF  : logical
>                 )
>
>   and I understand that you can set options in "optEOF (logical)" such as
> using correlation matrix and setting the % of non-missing points.
>
>   However, I found a couple of examples using "eofunc" like below,
>
>    $ evec= eofunc(ptw,neval,80.)
>   (Example 7 on the NCL website)
>
>   and I am not 100% sure what the third option (80.) means in this case.
> I thought the third option supposed to be logical but apparently some
> of the example contains a number. I thought this is the same as setting
> the % of non-missing points because when I compared the two methods
> (i.e. one with setting the optEOF and the other just setting values like
> in Example 7), I see the same results (EOF) but am I correct on this?
>
>   If anyone can clarify on this that will be great.
> Thank you very much in advance.
>
>   Sincerely,
>
> Yohei Takano
>
> --
> Yohei Takano Ph.D
> Max Planck Institute for Meteorology
> Bundesstraße 53, Room 207
> 20146 Hamburg, Germany
> Tel: +49 (0)40 41173 - 150
> Email: yohei.takano at mpimet.mpg.de
> _______________________________________________
> ncl-talk mailing list
> ncl-talk at ucar.edu
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20170120/7e0f3fab/attachment.html