Pick

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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 XY is the item of Y at the location specified by X.

      G2 3('ABC' 1)('DEF' 2)('GHI' 3)('JKL' 4)('MNO' 5)('PQR' 6)
┌───────┬───────┬───────┐
│┌───┬─┐│┌───┬─┐│┌───┬─┐│
││ABC1│││DEF2│││GHI3││
│└───┴─┘│└───┴─┘│└───┴─┘│
├───────┼───────┼───────┤
│┌───┬─┐│┌───┬─┐│┌───┬─┐│
││JKL4│││MNO5│││PQR6││
│└───┴─┘│└───┴─┘│└───┴─┘│
└───────┴───────┴───────┘
      (2 1)G
┌───┬─┐
JKL4
└───┴─┘
      ((2 1)1)G
JKL
      ((2 1)1 2)G
K

See also

External links

Documentation


APL built-ins [edit]
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