Difference between revisions of "Shuffle"
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[[What's new in Analytica 4.0?]] >
 
[[What's new in Analytica 4.0?]] >
  
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= Function Shuffle(a [, i]) =
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= Function Shuffle(a '', i'') =
 
   
 
   
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Shuffle returns a random reordering (permutation) of the values in array a over index i. If you omit i, it shuffles over Run. [Since build 4.0.0.48.] You can use it generate an independent random sample from an existing probability distribution, a.  If a contains dimensions other than i, it shuffles each slice over those other dimensions independently over i.
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Shuffle returns a random reordering (permutation) of the values in array a over index i. If you omit i, it shuffles over [[Run]]. [Since build 4.0.0.48.] You can use it generate an independent random sample from an existing probability distribution, a.   
  
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== Declaration ==
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= Independent Shuffles =
  
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Shuffle(a: Array[i]; i: IndexType = Run)
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If ''a'' contains extra dimensions, or if you include the Over parameter, e.g.:
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:Shuffle(a,I,Over:J)
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then the elements are shuffled independently over those extra dimensions.
  
 
If you want to shuffle the slices of a multidimensional array over index i, without shuffling the values within each slice, use this method:
 
If you want to shuffle the slices of a multidimensional array over index i, without shuffling the values within each slice, use this method:
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This shuffles A over index I, but does not shuffle each slice of A for each value of I.
 
This shuffles A over index I, but does not shuffle each slice of A for each value of I.
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= Examples =
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To generate a random permutation of the numbers 1..100:
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  Index I:=1..100 do Shuffle(I,I)

Revision as of 23:48, 6 March 2008


What's new in Analytica 4.0? >

Function Shuffle(a , i)

Shuffle returns a random reordering (permutation) of the values in array a over index i. If you omit i, it shuffles over Run. [Since build 4.0.0.48.] You can use it generate an independent random sample from an existing probability distribution, a.

Independent Shuffles

If a contains extra dimensions, or if you include the Over parameter, e.g.:

Shuffle(a,I,Over:J)

then the elements are shuffled independently over those extra dimensions.

If you want to shuffle the slices of a multidimensional array over index i, without shuffling the values within each slice, use this method: 

A[@I = Shuffle(@I,I)]

This shuffles A over index I, but does not shuffle each slice of A for each value of I.

Examples

To generate a random permutation of the numbers 1..100: 

 Index I:=1..100 do Shuffle(I,I)
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