| Array into binary array [message #86538] |
Sun, 17 November 2013 23:51  |
Oliver Angelil
Messages: 11
Registered: November 2013
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Junior Member |
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I have an array:
A =MAKE_ARRAY(4000, 120, 60, 3, /FLOAT, VALUE =!VALUES.F_NaN)
It consists of numbers between 0 and 1 as well as NaN values. I want to make a binary array from this, such that when an element is NaN, it'll be 0 in the binary array, and when it is a number between 0 and 1, it'll be 1 in the binary array.
Perhaps there is a quick solution which I have not found yet?
Thanks in advance,
Oliver
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| Re: Array into binary array [message #86539 is a reply to message #86538] |
Mon, 18 November 2013 00:18  |
Helder Marchetto
Messages: 520
Registered: November 2011
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Senior Member |
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On Monday, November 18, 2013 8:51:09 AM UTC+1, Oliver Angelil wrote:
> I have an array:
>
>
>
> A =MAKE_ARRAY(4000, 120, 60, 3, /FLOAT, VALUE =!VALUES.F_NaN)
>
>
>
> It consists of numbers between 0 and 1 as well as NaN values. I want to make a binary array from this, such that when an element is NaN, it'll be 0 in the binary array, and when it is a number between 0 and 1, it'll be 1 in the binary array.
>
>
>
> Perhaps there is a quick solution which I have not found yet?
>
>
>
> Thanks in advance,
>
>
>
> Oliver
Hi Oliver,
how about using the FINITE() function (http://www.exelisvis.com/docs/FINITE.html).
IDL> PRINT, FINITE(ALOG(FINDGEN(10)-5.0))
0 0 0 0 0 0 1 1 1 1
IDL> help, FINITE(ALOG(FINDGEN(10)-5.0))
<Expression> BYTE = Array[10]
IDL> PRINT, ALOG(FINDGEN(10)-5.0)
-NaN -NaN -NaN -NaN -NaN -Inf 0.000000 0.693147 1.09861 1.38629
You might then use WHERE to locate the NaN or finite value accordingly.
So, in your case I would use something like this (free to modify):
B = BYTARR(4000, 120, 60, 3)
FiniteVals = WHERE(FINITE(A), Count)
IF Count GT 0 THEN B[FiniteVals] = 1B
Finite will find both NaNs and Inf. Use the appropriate keywords of Finite if you wish to select only one of the two.
Hope it helps.
Regards,
Helder
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| Re: Array into binary array [message #86540 is a reply to message #86538] |
Mon, 18 November 2013 00:57 |
lecacheux.alain
Messages: 325
Registered: January 2008
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Senior Member |
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Le lundi 18 novembre 2013 08:51:09 UTC+1, Oliver Angelil a écrit :
> I have an array:
>
>
>
> A =MAKE_ARRAY(4000, 120, 60, 3, /FLOAT, VALUE =!VALUES.F_NaN)
>
>
>
> It consists of numbers between 0 and 1 as well as NaN values. I want to make a binary array from this, such that when an element is NaN, it'll be 0 in the binary array, and when it is a number between 0 and 1, it'll be 1 in the binary array.
>
>
>
> Perhaps there is a quick solution which I have not found yet?
>
>
>
> Thanks in advance,
>
>
>
> Oliver
This is the purpose of the FINITE function. From IDL documentation:
"Returns 1 (True) if its argument is finite. If the argument is infinite or not a defined number (NaN), the FINITE function returns 0 (False). The result is a byte expression of the same structure as the argument X."
Then, you can simply write:
IDL> A =MAKE_ARRAY(4000, 120, 60, 3, /FLOAT, VALUE =!VALUES.F_NaN)
... populate A ...
IDL> B = Finite(A)
use B ...
alx.
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| Re: Array into binary array [message #86541 is a reply to message #86540] |
Mon, 18 November 2013 01:08 |
Oliver Angelil
Messages: 11
Registered: November 2013
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Junior Member |
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B = Finite(A)
is what I wanted. Wow, that was extremely easy. Thanks a lot you two!
Oliver
On Monday, 18 November 2013 09:57:53 UTC+1, alx wrote:
> Le lundi 18 novembre 2013 08:51:09 UTC+1, Oliver Angelil a écrit :
>
>> I have an array:
>
>>
>
>>
>
>>
>
>> A =MAKE_ARRAY(4000, 120, 60, 3, /FLOAT, VALUE =!VALUES.F_NaN)
>
>>
>
>>
>
>>
>
>> It consists of numbers between 0 and 1 as well as NaN values. I want to make a binary array from this, such that when an element is NaN, it'll be 0 in the binary array, and when it is a number between 0 and 1, it'll be 1 in the binary array.
>
>>
>
>>
>
>>
>
>> Perhaps there is a quick solution which I have not found yet?
>
>>
>
>>
>
>>
>
>> Thanks in advance,
>
>>
>
>>
>
>>
>
>> Oliver
>
>
>
> This is the purpose of the FINITE function. From IDL documentation:
>
>
>
> "Returns 1 (True) if its argument is finite. If the argument is infinite or not a defined number (NaN), the FINITE function returns 0 (False). The result is a byte expression of the same structure as the argument X."
>
>
>
> Then, you can simply write:
>
> IDL> A =MAKE_ARRAY(4000, 120, 60, 3, /FLOAT, VALUE =!VALUES.F_NaN)
>
> ... populate A ...
>
> IDL> B = Finite(A)
>
> use B ...
>
>
>
> alx.
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