[MAHOUT-1728] in-core functional assignments

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.10.2
• Assignee: Dmitriy Lyubimov
• Reporter: Dmitriy Lyubimov
• Created: 02/Jun/15 23:43
• Updated: 07/Aug/15 15:56
• Resolved: 17/Jun/15 18:59

Description

in-core functional assignments (for vector and matrices)

mxA :=

{ (x) => x * x}

mxA :=

{ (row, col, x} => ... }
mxA ::={ (x) => ... }
mxA ::={ (row, col, x}

=> ...}
vec :=

{ (x) => ...}
vec :={ (idx, x) => ..}
vec ::= { (x) => ...}

vec ::=

{ (ind, x) => ...}

the `:=` assignmentn applies the function to all elements of tensor.
the `::=` assignment ignores zero elements of the tensor to improve performance.

matrix functions iterations use matrix structural flavor to optimize traversal.

further examples.

mxA := exp _ (in-place exponent)

v ::= abs _

PR https://github.com/apache/mahout/pull/135