107 lines
2.8 KiB
Plaintext
107 lines
2.8 KiB
Plaintext
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{{alias}}( N, alpha, x, stride )
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Multiplies a vector `x` by a constant `alpha`.
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The `N` and `stride` parameters determine which elements in `x` are accessed
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at runtime.
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Indexing is relative to the first index. To introduce an offset, use typed
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array views.
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If `N <= 0` or `stride <= 0`, the function returns `x` unchanged.
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Parameters
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----------
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N: integer
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Number of indexed elements.
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alpha: number
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Constant.
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x: Array<number>|TypedArray
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Input array.
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stride: integer
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Index increment for `x`.
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Returns
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-------
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x: Array<number>|TypedArray
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Input array.
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Examples
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--------
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// Standard Usage:
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> var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, -1.0, -3.0 ];
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> var alpha = 5.0;
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> {{alias}}( x.length, alpha, x, 1 )
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[ -10.0, 5.0, 15.0, -25.0, 20.0, -5.0, -15.0 ]
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// Using `N` and `stride` parameters:
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> x = [ -2.0, 1.0, 3.0, -5.0, 4.0, -1.0, -3.0 ];
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> var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 );
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> alpha = 5.0;
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> var stride = 2;
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> {{alias}}( N, alpha, x, stride )
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[ -10.0, 1.0, 15.0, -5.0, 20.0, -1.0, -3.0 ]
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// Using view offsets:
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> var x0 = new {{alias:@stdlib/array/float64}}( [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ] );
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> var x1 = new {{alias:@stdlib/array/float64}}( x0.buffer, x0.BYTES_PER_ELEMENT*1 );
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> N = {{alias:@stdlib/math/base/special/floor}}( x0.length / 2 );
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> alpha = 5.0;
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> stride = 2;
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> {{alias}}( N, alpha, x1, stride )
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<Float64Array>[ -10.0, 3.0, -20.0, 5.0, -30.0 ]
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> x0
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<Float64Array>[ 1.0, -10.0, 3.0, -20.0, 5.0, -30.0 ]
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{{alias}}.ndarray( N, alpha, x, stride, offset )
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Multiplies `x` by a constant `alpha` using alternative indexing semantics.
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While typed array views mandate a view offset based on the underlying
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buffer, the `offset` parameter supports indexing semantics based on a
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starting index.
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Parameters
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----------
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N: integer
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Number of indexed elements.
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alpha: number
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Constant.
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x: Array<number>|TypedArray
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Input array.
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stride: integer
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Index increment for `x`.
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offset: integer
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Starting index of `x`.
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Returns
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-------
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x: Array<number>|TypedArray
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Input array.
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Examples
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--------
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// Standard Usage:
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> var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, -1.0, -3.0 ];
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> var alpha = 5.0;
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> {{alias}}.ndarray( x.length, alpha, x, 1, 0 )
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[ -10.0, 5.0, 15.0, -25.0, 20.0, -5.0, -15.0 ]
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// Using an index offset:
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> x = [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ];
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> var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 );
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> alpha = 5.0;
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> var stride = 2;
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> {{alias}}.ndarray( N, alpha, x, stride, 1 )
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[ 1.0, -10.0, 3.0, -20.0, 5.0, -30.0 ]
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See Also
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--------
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