@stdlib/strided
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Strided.
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{{alias}}( N, x, sx, y, sy, fcn, clbk[, thisArg] )
Applies a unary function to each element retrieved from a strided input
array according to a callback function and assigns results to a strided
output array.
The `N` and stride parameters determine which elements in `x` and `y` are
accessed at runtime.
Indexing is relative to the first index. To introduce an offset, use typed
array views.
The callback function is provided four arguments:
- value: array element.
- idx: iteration index.
- indices: strided indices (offset + idx*stride).
- arrays: input and output arrays.
If the callback function does not return any value (or equivalently,
explicitly returns `undefined`), the value is ignored.
Parameters
----------
N: integer
Number of indexed elements.
x: Array|TypedArray|Object
Input array/collection. If provided an object, the object must be array-
like (excluding strings and functions).
sx: integer
Index increment for `x`.
y: Array|TypedArray|Object
Destination array/collection. If provided an object, the object must be
array-like (excluding strings and functions).
sy: integer
Index increment for `y`.
fcn: Function
Unary function to apply to callback return values.
clbk: Function
Callback function.
thisArg: any (optional)
Callback execution context.
Returns
-------
y: Array|TypedArray|Object
Destination array/collection.
Examples
--------
// Standard usage:
> var x = [ 1.0, -2.0, 3.0, -4.0 ];
> var y = [ 0.0, 0.0, 0.0, 0.0 ];
> function clbk( v ) { return v * 2.0; };
> {{alias}}( x.length, x, 1, y, 1, {{alias:/math/base/special/abs}}, clbk )
[ 2.0, 4.0, 6.0, 8.0 ]
// Using `N` and stride parameters:
> y = [ 0.0, 0.0, 0.0, 0.0 ];
> {{alias}}( 2, x, 2, y, -1, {{alias:/math/base/special/abs}}, clbk )
[ 6.0, 2.0, 0.0, 0.0 ]
// Using view offsets:
> var x0 = new {{alias:/array/float64}}( [ 1.0, -2.0, 3.0, -4.0 ] );
> var y0 = new {{alias:/array/float64}}( [ 0.0, 0.0, 0.0, 0.0 ] );
> var x1 = new {{alias:/array/float64}}( x0.buffer, x0.BYTES_PER_ELEMENT*1 );
> var y1 = new {{alias:/array/float64}}( y0.buffer, y0.BYTES_PER_ELEMENT*2 );
> {{alias}}( 2, x1, -2, y1, 1, {{alias:/math/base/special/abs}}, clbk )
<Float64Array>[ 8.0, 4.0 ]
> y0
<Float64Array>[ 0.0, 0.0, 8.0, 4.0 ]
{{alias}}.ndarray( N, x, sx, ox, y, sy, oy, fcn, clbk[, thisArg] )
Applies a unary function to each element retrieved from a strided input
array according to a callback function and assigns results to a strided
output array using alternative indexing semantics.
While typed array views mandate a view offset based on the underlying
buffer, the offsest parameters support indexing semantics
based on starting indices.
Parameters
----------
N: integer
Number of indexed elements.
x: Array|TypedArray|Object
Input array/collection. If provided an object, the object must be array-
like (excluding strings and functions).
sx: integer
Index increment for `x`.
ox: integer
Starting index for `x`.
y: Array|TypedArray|Object
Destination array/collection. If provided an object, the object must be
array-like (excluding strings and functions).
sy: integer
Index increment for `y`.
oy: integer
Starting index for `y`.
fcn: Function
Unary function to apply to callback return values.
clbk: Function
Callback function.
thisArg: any (optional)
Callback execution context.
Returns
-------
y: Array|TypedArray|Object
Destination array/collection.
Examples
--------
// Standard usage:
> var x = [ 1.0, -2.0, 3.0, -4.0 ];
> var y = [ 0.0, 0.0, 0.0, 0.0 ];
> function clbk( v ) { return v * 2.0; };
> {{alias}}.ndarray( x.length, x, 1, 0, y, 1, 0, {{alias:/math/base/special/abs}}, clbk )
[ 2.0, 4.0, 6.0, 8.0 ]
// Advanced indexing:
> x = [ 1.0, -2.0, 3.0, -4.0 ];
> y = [ 0.0, 0.0, 0.0, 0.0 ];
> {{alias}}.ndarray( 2, x, 2, 1, y, -1, y.length-1, {{alias:/math/base/special/abs}}, clbk )
[ 0.0, 0.0, 8.0, 4.0 ]
See Also
--------