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Re: Using two different arrays in tha same calculation [message #2295 is a reply to message #2243]

Fri, 10 June 1994 00:44

steinhh
Messages: 260
Registered: June 1994

Senior Member

In article <thompson.771168039@serts.gsfc.nasa.gov>, thompson@serts.gsfc.nasa.gov (William Thompson) writes:
|> ragnar@kvark.fi.uib.no (Ragnar Aas) writes:
|>
|> >I have the following problem :
|>
|> >I have two different arrays, (8) of float and (300,8) of float.
|> >I want to vectorize the equation and therefore I need to use both
|> >arrays in the same equation. For example :
|>
|> >newarray=cos(small_array)*sin(large_array)
|>
|> >where I want the data in small_array to be used over and over 300 times
|> >in this calculation.
|>
|> That's simple,
|>
|> newarray = cos(replicate(1,300)#small_array) * sin(large_array)

It certainly does the trick, Bill, but I wouldn't think that it's more efficient
doing 8*300 cosine operations just to vectorize a multiplication of 8*300 elements :-)
I'd suggest instead:

newarray = replicate(1,300)#cos(small_array) * sin(large_array)

or (I don't know which is the more efficient - would be nice to get some feedback):

small_array = reform(small_array,1,8)
newarray = rebin(cos(small_array),300,8,/sample) * sin(large_array)

Stein Vidar

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[Message index]

		Re: Using two different arrays in tha same calculation By: landers on Thu, 16 June 1994 06:52
		Re: Using two different arrays in tha same calculation By: dan on Wed, 08 June 1994 07:42
		Re: Using two different arrays in tha same calculation By: landers on Thu, 09 June 1994 09:09
		Re: Using two different arrays in tha same calculation By: steinhh on Fri, 10 June 1994 00:44
		Re: Using two different arrays in tha same calculation By: thompson on Thu, 09 June 1994 06:20

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