sum

The C++ interface for sum. More...

array	sum (const array &input, int dim=-1)
template<typename ty >
ty	sum (const array &input)

Detailed Description

The C++ interface for sum.

Sum is a reduction operation that computes the arithmetic
sum of the elements in an array.

The first sum function sums elements along a specific dimension
of the array. The defualt dimension is the first non-singleton
dimension.

array a = constant(1,5,5);
//a = 1 1 1 1 1
//  = 1 1 1 1 1
//  = 1 1 1 1 1
//  = 1 1 1 1 1
//  = 1 1 1 1 1

b = sum(a); //b = [5]
            //    [5]
            //    [5]
            //    [5]
            //    [5]

The second form of sum is templated, and returns the sum of all array elements to the host.

float hx[] = { -3, -5, 2, -9 };
array x1(2,2, hx); // x1 = -3  2
                   //      -5 -9
printf("%g\n", sum<float>(x1)); // -15

Function Documentation

array af::sum	(	const array &	input,
		int	dim = -1
	)

Parameters

[in]	input
[in]	dim	dimension along which to operate (-1 indicates first non-singleton dimension)

Returns

array of size equal to the dimension with values summed along the dimension dim in the input.

Examples:

examples/getting_started/gfor.cpp, examples/getting_started/integer.cpp, and examples/machine_learning/kmeans.cpp.

ty af::sum

(

const array &

input

)

Parameters

[in]

input

the array of values to sum

Returns

sum of all values in the input array