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{{Built-in|Pick|⊃}} is a [[dyadic]] [[primitive function]] which performs deep [[indexing]] on a possibly [[nested array]]. Pick allows to extract a value through multiple layers of nesting in a single function application. Pick shares the [[glyph]] <source lang=apl inline>⊃</source> with [[First]] or [[Mix]] depending on the dialect.
{{Built-in|Pick|⊃}} is a [[dyadic]] [[primitive function]] which performs deep [[indexing]] on a possibly [[nested array]]. Pick allows to extract a value through multiple layers of nesting in a single function application. Pick uses the [[Right Shoe]] glyph.


== Examples ==
== Examples ==

Revision as of 10:02, 9 June 2020

Pick () is a dyadic primitive function which performs deep indexing on a possibly nested array. Pick allows to extract a value through multiple layers of nesting in a single function application. Pick uses the Right Shoe glyph.

Examples

The left argument X must be a vector where each element of X specifies the multi-dimensional index at each layer of the right argument Y. The result of X⊃Y is the item of Y at the location specified by X.

      ⎕←G←2 3⍴('ABC' 1)('DEF' 2)('GHI' 3)('JKL' 4)('MNO' 5)('PQR' 6)
┌───────┬───────┬───────┐
│┌───┬─┐│┌───┬─┐│┌───┬─┐│
││ABC│1│││DEF│2│││GHI│3││
│└───┴─┘│└───┴─┘│└───┴─┘│
├───────┼───────┼───────┤
│┌───┬─┐│┌───┬─┐│┌───┬─┐│
││JKL│4│││MNO│5│││PQR│6││
│└───┴─┘│└───┴─┘│└───┴─┘│
└───────┴───────┴───────┘
      (⊂2 1)⊃G
┌───┬─┐
│JKL│4│
└───┴─┘
      ((2 1)1)⊃G
JKL
      ((2 1)1 2)⊃G
K

External links

Documentation


APL built-ins [edit]
Primitives (Timeline) Functions
Scalar
Monadic ConjugateNegateSignumReciprocalMagnitudeExponentialNatural LogarithmFloorCeilingFactorialNotPi TimesRollTypeImaginarySquare Root
Dyadic AddSubtractTimesDivideResiduePowerLogarithmMinimumMaximumBinomialComparison functionsBoolean functions (And, Or, Nand, Nor) ∙ GCDLCMCircularComplexRoot
Non-Scalar
Structural ShapeReshapeTallyDepthRavelEnlistTableCatenateReverseRotateTransposeRazeMixSplitEncloseNestCut (K)PairLinkPartitioned EnclosePartition
Selection FirstPickTakeDropUniqueIdentityStopSelectReplicateExpandSet functions (IntersectionUnionWithout) ∙ Bracket indexingIndexCartesian ProductSort
Selector Index generatorGradeIndex OfInterval IndexIndicesDealPrefix and suffix vectors
Computational MatchNot MatchMembershipFindNub SieveEncodeDecodeMatrix InverseMatrix DivideFormatExecuteMaterialiseRange
Operators Monadic EachCommuteConstantReplicateExpandReduceWindowed ReduceScanOuter ProductKeyI-BeamSpawnFunction axis
Dyadic BindCompositions (Compose, Reverse Compose, Beside, Withe, Atop, Over) ∙ Inner ProductDeterminantPowerAtUnderRankDepthVariantStencilCutDirect definition (operator)
Quad names Index originComparison toleranceMigration levelAtomic vector