floor

Round each element in a strided array toward negative infinity.

Usage

var floor = require( '@stdlib/math/strided/special/floor' );

floor( N, dtypeX, x, strideX, dtypeY, y, strideY )

Rounds each element in a strided array x toward negative infinity and assigns the results to elements in a strided array y.

var Float64Array = require( '@stdlib/array/float64' );

var x = new Float64Array( [ -1.5, 2.3, -3.9, 4.2, -5.0 ] );

// Perform operation in-place:
floor( x.length, 'float64', x, 1, 'float64', x, 1 );
// x => <Float64Array>[ -2.0, 2.0, -4.0, 4.0, -5.0 ]

The function accepts the following arguments:

N: number of indexed elements.
dtypeX: data type for x.
x: input array-like object.
strideX: index increment for x.
dtypeY: data type for y.
y: output array-like object.
strideY: index increment for y.

The N and stride parameters determine which elements in x and y are accessed at runtime. For example, to index every other value in x and the first N elements of y in reverse order,

var Float64Array = require( '@stdlib/array/float64' );

var x = new Float64Array( [ -1.5, 2.3, -3.9, 4.2, -5.0, -6.0 ] );
var y = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );

floor( 3, 'float64', x, 2, 'float64', y, -1 );
// y => <Float64Array>[ -5.0, -4.0, -2.0, 0.0, 0.0, 0.0 ]

Note that indexing is relative to the first index. To introduce an offset, use typed array views.

var Float64Array = require( '@stdlib/array/float64' );

// Initial arrays...
var x0 = new Float64Array( [ -1.5, 2.3, -3.9, 4.2, -5.0, -6.0 ] );
var y0 = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );

// Create offset views...
var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var y1 = new Float64Array( y0.buffer, y0.BYTES_PER_ELEMENT*3 ); // start at 4th element

floor( 3, 'float64', x1, -2, 'float64', y1, 1 );
// y0 => <Float64Array>[ 0.0, 0.0, 0.0, -6.0, 4.0, 2.0 ]

floor.ndarray( N, dtypeX, x, strideX, offsetX, dtypeY, y, strideY, offsetY )

Rounds each element in a strided array x toward negative infinity and assigns the results to elements in a strided array y using alternative indexing semantics.

var Float64Array = require( '@stdlib/array/float64' );

var x = new Float64Array( [ -1.5, 2.3, -3.9, 4.2, -5.0 ] );
var y = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0 ] );

floor.ndarray( x.length, 'float64', x, 1, 0, 'float64', y, 1, 0 );
// y => <Float64Array>[ -2.0, 2.0, -4.0, 4.0, -5.0 ]

The function accepts the following additional arguments:

offsetX: starting index for x.
offsetY: starting index for y.

While typed array views mandate a view offset based on the underlying buffer, the offsetX and offsetY parameters support indexing semantics based on starting indices. For example, to index every other value in x starting from the second value and to index the last N elements in y,

var Float64Array = require( '@stdlib/array/float64' );

var x = new Float64Array( [ -1.5, 2.3, -3.9, 4.2, -5.0, -6.0 ] );
var y = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );

floor.ndarray( 3, 'float64', x, 2, 1, 'float64', y, -1, y.length-1 );
// y => <Float64Array>[ 0.0, 0.0, 0.0, -6.0, 4.0, 2.0 ]

Examples

var uniform = require( '@stdlib/random/base/uniform' ).factory;
var filledarray = require( '@stdlib/array/filled' );
var filledarrayBy = require( '@stdlib/array/filled-by' );
var dtypes = require( '@stdlib/array/dtypes' );
var floor = require( '@stdlib/math/strided/special/floor' );

var dt;
var x;
var y;
var i;

dt = dtypes();
for ( i = 0; i < dt.length; i++ ) {
    x = filledarrayBy( 10, dt[ i ], uniform( -100.0, 100.0 ) );
    console.log( x );

    y = filledarray( 0.0, x.length, 'generic' );
    console.log( y );

    floor.ndarray( x.length, dt[ i ], x, 1, 0, 'generic', y, -1, y.length-1 );
    console.log( y );
    console.log( '' );
}