repl.txt (3418B)
1 2 {{alias}}( N, alpha, x, strideX, y, strideY ) 3 Multiplies `x` by a constant `alpha` and adds the result to `y`. 4 5 The `N` and `stride` parameters determine which elements in `x` and `y` are 6 accessed at runtime. 7 8 Indexing is relative to the first index. To introduce an offset, use typed 9 array views. 10 11 If `N <= 0` or `alpha == 0`, the function returns `y` unchanged. 12 13 Parameters 14 ---------- 15 N: integer 16 Number of indexed elements. 17 18 alpha: number 19 Constant. 20 21 x: Array<number>|TypedArray 22 Input array. 23 24 strideX: integer 25 Index increment for `x`. 26 27 y: Array<number>|TypedArray 28 Destination array. 29 30 strideY: integer 31 Index increment for `y`. 32 33 Returns 34 ------- 35 y: Array<number>|TypedArray 36 Input array `y`. 37 38 Examples 39 -------- 40 // Standard usage: 41 > var x = [ 1.0, 2.0, 3.0, 4.0, 5.0 ]; 42 > var y = [ 1.0, 1.0, 1.0, 1.0, 1.0 ]; 43 > var alpha = 5.0; 44 > {{alias}}( x.length, alpha, x, 1, y, 1 ) 45 [ 6.0, 11.0, 16.0, 21.0, 26.0 ] 46 47 // Using `N` and `stride` parameters: 48 > x = [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ]; 49 > y = [ 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 ]; 50 > var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 ); 51 > {{alias}}( N, alpha, x, 2, y, -1 ) 52 [ 26.0, 16.0, 6.0, 1.0, 1.0, 1.0 ] 53 54 // Using view offsets: 55 > var x0 = new {{alias:@stdlib/array/float64}}( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] ); 56 > var y0 = new {{alias:@stdlib/array/float64}}( [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] ); 57 > var x1 = new {{alias:@stdlib/array/float64}}( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); 58 > var y1 = new {{alias:@stdlib/array/float64}}( y0.buffer, y0.BYTES_PER_ELEMENT*3 ); 59 > N = {{alias:@stdlib/math/base/special/floor}}( x0.length / 2 ); 60 > {{alias}}( N, 5.0, x1, -2, y1, 1 ) 61 <Float64Array>[ 40.0, 31.0, 22.0 ] 62 > y0 63 <Float64Array>[ 7.0, 8.0, 9.0, 40.0, 31.0, 22.0 ] 64 65 66 {{alias}}.ndarray( N, alpha, x, strideX, offsetX, y, strideY, offsetY ) 67 Multiplies `x` by a constant `alpha` and adds the result to `y`, with 68 alternative indexing semantics. 69 70 While typed array views mandate a view offset based on the underlying 71 buffer, the `offsetX` and `offsetY` parameters support indexing semantics 72 based on starting indices. 73 74 Parameters 75 ---------- 76 N: integer 77 Number of indexed elements. 78 79 alpha: number 80 Constant. 81 82 x: Array<number>|TypedArray 83 Input array. 84 85 strideX: integer 86 Index increment for `x`. 87 88 offsetX: integer 89 Starting index for `x`. 90 91 y: Array<number>|TypedArray 92 Destination array. 93 94 strideY: integer 95 Index increment for `y`. 96 97 offsetY: integer 98 Starting index for `y`. 99 100 Returns 101 ------- 102 y: Array<number>|TypedArray 103 Input array `y`. 104 105 Examples 106 -------- 107 // Standard usage: 108 > var x = [ 1.0, 2.0, 3.0, 4.0, 5.0 ]; 109 > var y = [ 1.0, 1.0, 1.0, 1.0, 1.0 ]; 110 > var alpha = 5.0; 111 > {{alias}}.ndarray( x.length, alpha, x, 1, 0, y, 1, 0 ) 112 [ 6.0, 11.0, 16.0, 21.0, 26.0 ] 113 114 // Advanced indexing: 115 > x = [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ]; 116 > y = [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ]; 117 > var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 ); 118 > {{alias}}.ndarray( N, alpha, x, 2, 1, y, -1, y.length-1 ) 119 [ 7.0, 8.0, 9.0, 40.0, 31.0, 22.0 ] 120 121 See Also 122 -------- 123