Sums, products and differences Routines

prod

public static prod($x, int $axis = NULL) : CArray

Return the product of array elements over a given axis.

CArray|Array $x Input array.

int $axis (optional) Axis or axes along which a product is performed.

CArray An array shaped as $x but with the specified axis removed. . If $axis is NULL an 0-d CArray is returned.

Example 1

echo CArray::prod([[1.,2.],[3.,4.]]);

24.000000

Example 2

echo CArray::prod([[1.,2.],[3.,4.]], 0);

[ 3.  8. ]

public static sum($x, int $axis = NULL) : CArray

Sum of array elements over a given axis.

CArray|Array $x Input array.

int $axis (optional) Axis or axes along which a sum is performed.

CArray An array shaped as $x but with the specified axis removed. . If $axis is NULL an 0-d CArray is returned.

Example 1

echo CArray::sum([[1.,2.],[3.,4.]]);

10.000000

Example 2

echo CArray::sum([[1.,2.],[3.,4.]]);

[ 4.  6. ]

public static cumprod($x, int $axis = 0) : CArray

Return the cumulative product of elements along a given axis.

CArray|Array $x Input array.

int $axis (optional) Axis along which the cumulative product is computed.

CArray An array shaped as $x. If $axis is NULL an 0-d CArray is returned.

Example 1

$a = new CArray([1, 2, 3]);
echo CArray::cumprod($a);

[ 1  2  6 ]

Example 2

$a = new CArray([[1, 2, 3], [4, 5, 6]]);
echo CArray::cumprod($a);

[   1    2    6   24  120  720 ]

public static cumsum($x) : CArray

Return the cumulative sum of elements along a given axis.

CArray|Array $x Input array.

int $axis (optional) Axis along which the cumulative sum is computed.

CArray An array shaped as $x. If $axis is NULL an 0-d CArray is returned.

Example 1

$a = new CArray([[1, 2, 3], [4, 5, 6]]);
echo CArray::cumsum($a);

[  1   3   6  10  15  21 ]

Example 2

echo CArray::cumsum([1, 2, 3]);

[ 1  3  6 ]