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Re: Filtering out NaNs [message #8515 is a reply to message #8502]

Thu, 20 March 1997 00:00

f055
Messages: 29
Registered: April 1995

Junior Member

-> |> There are some NaNs in my data which keep making my code fall over.
-> |> I'd like to either filter them out or avoid them in the calculation,
-> |> but doing something like
-> |>
-> |> a(where(a eq !values.f_nan) = missing_flag
-> |>
-> |> doesn't work. Does anyone have any suggestions?
-> |>
->
-> NaNs are characterized by the fact that they are *not* equal
-> to any number (that's what it says, isn't it :-)
->
-> In fact, it's not even equal to itself - and this is the distinguishing
-> feature that must be used to pick them out. I.e.,
->
-> a(where(a ne a)) = missing_flag
->

Somewhat less confusing, perhaps, to someone who later tries to debug/modify
your code might be:

a(where(finite(a) eq 0)) = missing_flag

finite returns true (ne 0) only for numbers and not for things that are
"Not a Number" (or is it "Not a Numerical Quantity" = NanQ ?)

Tim

......................... Dr Tim Osborn . t.osborn@uea.ac.uk
.... ___/.. __ /.. /.. /. Senior Research Associate . phone:01603 592089
... /..... /. /.. /.. /.. Climatic Research Unit . fax: 01603 507784
.. /..... __/.. /.. /... School of Environmental Sciences.
. /..... /\ ... /.. /.... University of East Anglia .
____/.._/..\_..____/..... Norwich NR4 7TJ .
......................... UK .

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[Message index]

		Re: Filtering out NaNs By: Dale Bailey on Thu, 20 March 1997 00:00
		Re: Filtering out NaNs By: thompson on Thu, 20 March 1997 00:00
		Re: Filtering out NaNs By: peter on Thu, 20 March 1997 00:00
		Re: Filtering out NaNs By: bowman on Thu, 20 March 1997 00:00
		Re: Filtering out NaNs By: f055 on Thu, 20 March 1997 00:00
		Re: Filtering out NaNs By: sritcey on Thu, 20 March 1997 00:00
		Re: Filtering out NaNs By: bowman on Wed, 19 March 1997 00:00
		Re: Filtering out NaNs By: davidf on Wed, 19 March 1997 00:00
		Re: Filtering out NaNs By: Tim Patterson on Wed, 19 March 1997 00:00

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