120 lines
3.6 KiB
Plaintext
120 lines
3.6 KiB
Plaintext
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{{alias}}( N, x, strideX, y, strideY )
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Computes the dot product of two double-precision floating-point vectors.
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The `N`, `strideX`, and `strideY` parameters determine which elements in `x`
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and `y` are accessed at runtime.
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Indexing is relative to the first index. To introduce an offset, use a typed
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array view.
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If `N <= 0`, the function returns `0.0`.
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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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x: Float64Array
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First input array.
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strideX: integer
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Index increment for `x`.
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y: Float64Array
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Second input array.
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strideY: integer
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Index increment for `y`.
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Returns
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-------
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dot: number
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The dot product of `x` and `y`.
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Examples
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--------
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// Standard usage:
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> var x = new {{alias:@stdlib/array/float64}}( [ 4.0, 2.0, -3.0, 5.0, -1.0 ] );
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> var y = new {{alias:@stdlib/array/float64}}( [ 2.0, 6.0, -1.0, -4.0, 8.0 ] );
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> var dot = {{alias}}( x.length, x, 1, y, 1 )
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-5.0
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// Strides:
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> x = new {{alias:@stdlib/array/float64}}( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
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> y = new {{alias:@stdlib/array/float64}}( [ 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 ] );
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> var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 );
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> dot = {{alias}}( N, x, 2, y, -1 )
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9.0
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// Using view offsets:
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> x = new {{alias:@stdlib/array/float64}}( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
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> y = new {{alias:@stdlib/array/float64}}( [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
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> var x1 = new {{alias:@stdlib/array/float64}}( x.buffer, x.BYTES_PER_ELEMENT*1 );
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> var y1 = new {{alias:@stdlib/array/float64}}( y.buffer, y.BYTES_PER_ELEMENT*3 );
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> N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 );
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> dot = {{alias}}( N, x1, -2, y1, 1 )
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128.0
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{{alias}}.ndarray( N, x, strideX, offsetX, y, strideY, offsetY )
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Computes the dot product of two double-precision floating-point vectors
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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 `offsetX` and `offsetY` parameters support indexing 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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x: Float64Array
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First input array.
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strideX: integer
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Index increment for `x`.
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offsetX: integer
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Starting index for `x`.
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y: Float64Array
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Second input array.
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strideY: integer
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Index increment for `y`.
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offsetY: integer
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Starting index for `y`.
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Returns
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-------
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dot: number
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The dot product of `x` and `y`.
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Examples
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--------
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// Standard usage:
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> var x = new {{alias:@stdlib/array/float64}}( [ 4.0, 2.0, -3.0, 5.0, -1.0 ] );
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> var y = new {{alias:@stdlib/array/float64}}( [ 2.0, 6.0, -1.0, -4.0, 8.0 ] );
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> var dot = {{alias}}.ndarray( x.length, x, 1, 0, y, 1, 0 )
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-5.0
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// Strides:
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> x = new {{alias:@stdlib/array/float64}}( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
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> y = new {{alias:@stdlib/array/float64}}( [ 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 ] );
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> var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 );
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> dot = {{alias}}.ndarray( N, x, 2, 0, y, 2, 0 )
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9.0
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// Using offset indices:
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> x = new {{alias:@stdlib/array/float64}}( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
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> y = new {{alias:@stdlib/array/float64}}( [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
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> N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 );
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> dot = {{alias}}.ndarray( N, x, -2, x.length-1, y, 1, 3 )
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128.0
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See Also
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--------
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