# A .pos( x )

Description:

Get the positions of sequence members in another sequence.

Syntax:

A.pos(x)

Note:

x is a sequence. The function returns integer sequence p which satisfies A(p)==x, and returns null if it cannot find the positions for all members of x.

Parameters:

 A A sequence x A sequence

Options:

 @i Return a monitonically increasing integer sequence p which satisfies A(p)==x @c Return the position in which sequence x first appears in A. By doing so, the position of sub-sequence x in sequence A can be located. If x is not the sub-sequence of A, then return null. @b Use the binary search to query the location. In this case A is by default assumed as an ordered sequence. Both Increasing and decreasing are applicable

Return value:

A monotonically increasing integer sequence or an integer sequence

Example:

 [6,2,1,4,6,3,7,8].pos@i([1,4,6]) [3,4,5], which is a monitonically increasing integer sequence [6,2,1,4,6,3,7,8].posi([1,4,6]) [3,4,1], which is an integer sequence [1,2,3,4,6,7,8].pos@b([3,1,4,6]) [3,1,4,5] [2,1,4,6,3,7,8].pos@i([8,4,6]) null [2,1,4,6,3,7,8,4,6,1].pos@c([4,6]) [3]

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