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Re: transforming an array where some values can't [message #10908 is a reply to message #10907]

Thu, 05 February 1998 00:00

meron
Messages: 51
Registered: July 1995

Member

In article <1998Feb5.094807.1@eisner>, bowler@eisner.decus.org writes:
> I'm trying to write a function that will transform an arbitrary array by taking
> hte natural log of every element in the array.
>
> What I have is
>
> function xform, input
> temp = alog(input) ; I realize I could combine these 2 statements
> return, temp ; but it makes debugging easier
> end
>
> Unfortunately, I can't guarentee that there won't be some elements that are
> zero and thus invalid arguments to alog. what's the "most efficient" way to
> take the alog of any element that's greater than 0 and set the value of ony
> that are less than or equal to 0 to some small value (1e-7 for example)?
>
Just do
function xform, input
eps = ..some small value here, can make it input parameter too ..
temp = alog(input > eps) ; I realize I could combine these 2 statements
return, temp ; but it makes debugging easier
end

Mati Meron | "When you argue with a fool,
meron@cars.uchicago.edu | chances are he is doing just the same"

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[Message index]

		Re: transforming an array where some values can't By: Evilio del Rio on Mon, 09 February 1998 00:00
		Re: transforming an array where some values can't By: alpha on Sun, 08 February 1998 00:00
		Re: transforming an array where some values can't By: offenbrg on Fri, 06 February 1998 00:00
		Re: transforming an array where some values can't By: S Penzes on Thu, 05 February 1998 00:00
		Re: transforming an array where some values can't By: meron on Thu, 05 February 1998 00:00

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