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BYTSCL and NAN keyword [message #38282]

Tue, 02 March 2004 08:54

K. Bowman
Messages: 330
Registered: May 2000

Senior Member

Has anyone else noticed this problem with BYTSCL and the NAN keyword?

The BYTSCL function scales integers and floats into bytes between 0 and
255 (or the value set by the TOP keyword). If the NAN keyword is set,
NANs in the input array are set to 0 in the output array. But 0 falls
into the valid range for good values (0 to TOP)!

Because it is not possible to set NANs to a value outside the valid
range (greater than TOP), it is not possible to distinguish missing from
valid data.

As best I can tell, the only solution is to not use the NAN keyword and
scale the valid data only by using WHERE to find all the valid values.
Am I missing something obvious? (Quite possible, I admit.)

Ken Bowman

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[Message index]

		BYTSCL and NAN keyword By: K. Bowman on Tue, 02 March 2004 08:54
		Re: BYTSCL and NAN keyword By: K. Bowman on Wed, 03 March 2004 13:35
		Re: BYTSCL and NAN keyword By: Craig Markwardt on Wed, 03 March 2004 08:41
		Re: BYTSCL and NAN keyword By: Craig Markwardt on Wed, 03 March 2004 00:10
		Re: BYTSCL and NAN keyword By: David Fanning on Tue, 02 March 2004 18:18
		Re: BYTSCL and NAN keyword By: David Fanning on Tue, 02 March 2004 18:15

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