segsum

The C++ interface for segsum. More...

array	segsum (const array &input, const array &segments, bool reduce=false)

Detailed Description

The C++ interface for segsum.

Segmented sum of a set of elements

Function Documentation

array af::segsum	(	const array &	input,
		const array &	segments,
		bool	reduce = false
	)

float h_values[] = {1, 2, 3, 4, 5};
float h_keys  [] = {1, 2, 2, 2, 3};
array values = array(1, 5, h_values);
array keys = array(1, 5, h_keys);
array res_scan = segsum(values, keys); // segsum(values, keys, false);
array res_sum = segsum(values, keys, true);
print(res_scan); // 1.00 2.00 5.00 9.00 5.00
print(res_sum);  // 0.00 1.00 9.00 5.00 0.00

Segmented sum

Parameters

[in]	input	values to sum (treated as vector)
[in]	segments	The vector denoting segment number. Should be sorted.
[in]	reduce	Segmented operation: cumulation (false) or reduction (true)

Returns

Vector containing the

• cumulative sums for each segment , if reduce is false
• sum at the end of each segment, if reduce is true