Command: Part

Name:
Part - returns a sub-array of an array

Synopsis:
array1 array2 Part -> array3

Description:
Part returns a sub-array of array1 specified by array2. This function is an implementation of Mathematica's Part function. It can also be used to rearrange or copy parts of array1. Note, Mathematica-style functions in SLI use Mathematica index notation.

Parameters:
array1 is an arbitrarily shaped array. In particular it does not need to be rectangular. array2 is an array [i,j, ...] where the i,j specify the selected elements on each level. Any i,j can itself be an array [i1,i2,....] specifying a list of elements on that level. When i is the literal /All, all elements on the corresponding level are returned. The first element on each level has index 1. Indices can also be specified counting from the end of the array, in this case the last element has index -1. Positive and neative indices can arbitrarily be intermixed. Alternatives: Function Part_a (undocumented) -> behaviour and synopsis are the same.

Examples:
[ [3 5 6 9] [11 4 7 2] [-9 1 8 10] ] [ [1 3] [2 3] ] Part --> [[5 6] [1 8]] [ [3 [-12 -19] 6 9] [11 4 7 2] [-9 1 8 10] ] [ 1 2 2] Part --> -19 [3 4 5 6 7] [-2] Part --> 6 [3 [-9 -12] 5 6 7] [2] Part --> [-9 -12] [3 [-9 -12] 5 6 7] [2 2] Part --> -12 [3 [-9 -12] 5 6 7] [[2 3]] Part --> [[-9 -12] 5] [3 [-9 -12] 5 6 7] [[2 3 2]] Part --> [[-9 -12] 5 [-9 -12]] [ [3 5 6 9] [11 4 7 2] [-9 1 8 10] ] [ 1 [] ] Part --> [] [ [3 5 6 9] [11 4 7 2] [-9 1 8 10] ] [ [] 1 ] Part --> [] [3 [5 -12] 6 9] [ [ 2 ] ] Part --> [[5 -12]] [3 [5 -12] 6 9] [ [ 2 ] 2] Part --> [-12] [ [3 5 6 9] [11 4 7 2] [-9 1 8 10] ] [ /All [3 2] ] Part --> [[6 5] [7 4] [8 1]]

Bugs:

Author:
Diesmann

FirstVersion:
29.9.1999

Remarks:
Literal /All plays the role of the index specifier ':' in Matlab when used without arguments. Note, that Matlab in addition provides specifier 'end'. This is not necessary in the formalism of Mathematica because indices counting from the end of the array can be expressed by negative values.
SeeAlso: MathematicaToSliIndex

References:
[1] The Mathematica Book V4.0 "Part"

Source:
/home/abuild/rpmbuild/BUILD/nest-2.4.1/lib/sli/mathematica.sli

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Name:	Part - returns a sub-array of an array
Synopsis:	array1 array2 Part -> array3
Description:	Part returns a sub-array of array1 specified by array2. This function is an implementation of Mathematica's Part function. It can also be used to rearrange or copy parts of array1. Note, Mathematica-style functions in SLI use Mathematica index notation.
Parameters:	array1 is an arbitrarily shaped array. In particular it does not need to be rectangular. array2 is an array [i,j, ...] where the i,j specify the selected elements on each level. Any i,j can itself be an array [i1,i2,....] specifying a list of elements on that level. When i is the literal /All, all elements on the corresponding level are returned. The first element on each level has index 1. Indices can also be specified counting from the end of the array, in this case the last element has index -1. Positive and neative indices can arbitrarily be intermixed. Alternatives: Function Part_a (undocumented) -> behaviour and synopsis are the same.
Examples:	[ [3 5 6 9] [11 4 7 2] [-9 1 8 10] ] [ [1 3] [2 3] ] Part --> [[5 6] [1 8]] [ [3 [-12 -19] 6 9] [11 4 7 2] [-9 1 8 10] ] [ 1 2 2] Part --> -19 [3 4 5 6 7] [-2] Part --> 6 [3 [-9 -12] 5 6 7] [2] Part --> [-9 -12] [3 [-9 -12] 5 6 7] [2 2] Part --> -12 [3 [-9 -12] 5 6 7] [[2 3]] Part --> [[-9 -12] 5] [3 [-9 -12] 5 6 7] [[2 3 2]] Part --> [[-9 -12] 5 [-9 -12]] [ [3 5 6 9] [11 4 7 2] [-9 1 8 10] ] [ 1 [] ] Part --> [] [ [3 5 6 9] [11 4 7 2] [-9 1 8 10] ] [ [] 1 ] Part --> [] [3 [5 -12] 6 9] [ [ 2 ] ] Part --> [[5 -12]] [3 [5 -12] 6 9] [ [ 2 ] 2] Part --> [-12] [ [3 5 6 9] [11 4 7 2] [-9 1 8 10] ] [ /All [3 2] ] Part --> [[6 5] [7 4] [8 1]]
Bugs:
Author:	Diesmann
FirstVersion:	29.9.1999
Remarks:	Literal /All plays the role of the index specifier ':' in Matlab when used without arguments. Note, that Matlab in addition provides specifier 'end'. This is not necessary in the formalism of Mathematica because indices counting from the end of the array can be expressed by negative values.
SeeAlso:	`MathematicaToSliIndex`
References:	[1] The Mathematica Book V4.0 "Part"
Source:	/home/abuild/rpmbuild/BUILD/nest-2.4.1/lib/sli/mathematica.sli