MarkLogic 12 EA 1 Product Documentation
vec:dimension

vec:dimension(
   $vector1 as vec:vector
) as xs:unsignedInt

Returns the dimension of the vector passed in.

Parameters
vector1	The vector to find the dimension of.

  xquery version "1.0-ml";
  vec:dimension(vec:vector((3.14, 1.59, 2.65)))

  => 3

MarkLogic 12 EA 1 Product Documentationvec:dimension