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Re: Image thresholding [message #15378]

Mon, 17 May 1999 00:00

David Kastrup
Messages: 33
Registered: February 1998

Member

davidf@dfanning.com (David Fanning) writes:

> David Brennan (9147261b@clinmed.gla.ac.uk) writes:
>
>> Does anyone know of a fast routine or function for searching through a
>> 3D data set and setting numbers within a predetermined range of values
>> to zero. i.e,
>>
>> the range is 5 - 10
>>
>> A data set contains [0,1,2,3,4,5,6,7,8,9]. It becomes
>> [0,1,2,3,4,0,0,0,0,0]
>>
>> This would save me a lot of time.
>
> a = [0,1,2,3,4,5,6,7,8,9]
> b = a
> b[Where(a ge 5 AND a LT 10)] = 0
> Print, b
> 0,1,2,3,4,0,0,0,0,0

You lose.

If I followup with:
IDL> a=b
IDL> b[Where(a ge 5 AND a LT 10)] = 0
% Attempt to subscript B with <LONG ( -1)> is out of range.
% Execution halted at: $MAIN$

As you can see IDL blows this handy construct if no elements meet the
conditions.

See separate post for correct solution.

--
David Kastrup Phone: +49-234-700-5570
Email: dak@neuroinformatik.ruhr-uni-bochum.de Fax: +49-234-709-4209
Institut fï¿½r Neuroinformatik, Universitï¿½tsstr. 150, 44780 Bochum, Germany

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		Re: Image thresholding By: David Kastrup on Mon, 17 May 1999 00:00
		Re: Image thresholding By: davidf on Mon, 17 May 1999 00:00
		Re: Image thresholding By: David Kastrup on Mon, 17 May 1999 00:00

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