ops_summary.rst

Summary of the Operations

Basics

• transform applies a function to each element of the sequence, equivalent to the functional operation map
• select takes the first N` elements of the sequence satisfying a condition (via a selection mask or a predicate function)
• unique returns unique elements within a sequence
• histogram generates a summary of the statistical distribution of the sequence

Aggregation

• reduce traverses the sequence while accumulating some data, equivalent to the functional operation fold_left
• scan is the cumulative version of reduce which returns the sequence of the intermediate values taken by the accumulator

Differentiation

• adjacent_difference computes the difference between the current element and the previous or next one in the sequence
• discontinuity detects value change between the current element and the previous or next one in the sequence

Rearrangement

• sort rearranges the sequence by sorting it. It could be according to a comparison operator or a value using a radix approach
• partial_sort rearranges the sequence by sorting it up to and including a given index, according to a comparison operator.
• nth_element places the nth element in its sorted position, with elements less-than before, and greater after, according to a comparison operator.
• exchange rearranges the elements according to a different stride configuration which is equivalent to a tensor axis transposition
• shuffle rotates the elements

Partition/Merge

• partition divides the sequence into two or more sequences according to a predicate while preserving some ordering properties
• merge merges two ordered sequences into one while preserving the order

Data Movement

• store stores the sequence to a continuous memory zone. There are variations to use an optimized path or to specify how to store the sequence to better fit the access patterns of the CUs.
• load the complementary operations of the above ones.
• memcpy copies bytes between device sources and destinations

Other operations

• run_length_encode generates a compact representation of a sequence
• binary_search finds for each element the index of an element with the same value in another sequence (which has to be sorted)
• config selects a kernel's grid/block dimensions to tune the operation to a GPU