repl.txt (4187B)
1 2 {{alias}}( N, correction, x, stride ) 3 Computes the variance of a single-precision floating-point strided array 4 ignoring `NaN` values. 5 6 The `N` and `stride` parameters determine which elements in `x` are accessed 7 at runtime. 8 9 Indexing is relative to the first index. To introduce an offset, use a typed 10 array view. 11 12 If `N <= 0`, the function returns `NaN`. 13 14 If every indexed element is `NaN`, the function returns `NaN`. 15 16 Parameters 17 ---------- 18 N: integer 19 Number of indexed elements. 20 21 correction: number 22 Degrees of freedom adjustment. Setting this parameter to a value other 23 than `0` has the effect of adjusting the divisor during the calculation 24 of the variance according to `n - c` where `c` corresponds to the 25 provided degrees of freedom adjustment and `n` corresponds to the number 26 of non-`NaN` indexed elements. When computing the variance of a 27 population, setting this parameter to `0` is the standard choice (i.e., 28 the provided array contains data constituting an entire population). 29 When computing the unbiased sample variance, setting this parameter to 30 `1` is the standard choice (i.e., the provided array contains data 31 sampled from a larger population; this is commonly referred to as 32 Bessel's correction). 33 34 x: Float32Array 35 Input array. 36 37 stride: integer 38 Index increment. 39 40 Returns 41 ------- 42 out: number 43 The variance. 44 45 Examples 46 -------- 47 // Standard Usage: 48 > var x = new {{alias:@stdlib/array/float32}}( [ 1.0, -2.0, NaN, 2.0 ] ); 49 > {{alias}}( x.length, 1, x, 1 ) 50 ~4.3333 51 52 // Using `N` and `stride` parameters: 53 > x = new {{alias:@stdlib/array/float32}}( [ -2.0, 1.0, 1.0, -5.0, 2.0, -1.0 ] ); 54 > var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 ); 55 > {{alias}}( N, 1, x, 2 ) 56 ~4.3333 57 58 // Using view offsets: 59 > var x0 = new {{alias:@stdlib/array/float32}}( [ 1.0, -2.0, 3.0, 2.0, 5.0, -1.0 ] ); 60 > var x1 = new {{alias:@stdlib/array/float32}}( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); 61 > N = {{alias:@stdlib/math/base/special/floor}}( x0.length / 2 ); 62 > {{alias}}( N, 1, x1, 2 ) 63 ~4.3333 64 65 {{alias}}.ndarray( N, correction, x, stride, offset ) 66 Computes the variance of a single-precision floating-point strided array 67 ignoring `NaN` values and using alternative indexing semantics. 68 69 While typed array views mandate a view offset based on the underlying 70 buffer, the `offset` parameter supports indexing semantics based on a 71 starting index. 72 73 Parameters 74 ---------- 75 N: integer 76 Number of indexed elements. 77 78 correction: number 79 Degrees of freedom adjustment. Setting this parameter to a value other 80 than `0` has the effect of adjusting the divisor during the calculation 81 of the variance according to `n - c` where `c` corresponds to the 82 provided degrees of freedom adjustment and `n` corresponds to the number 83 of non-`NaN` indexed elements. When computing the variance of a 84 population, setting this parameter to `0` is the standard choice (i.e., 85 the provided array contains data constituting an entire population). 86 When computing the unbiased sample variance, setting this parameter to 87 `1` is the standard choice (i.e., the provided array contains data 88 sampled from a larger population; this is commonly referred to as 89 Bessel's correction). 90 91 x: Float32Array 92 Input array. 93 94 stride: integer 95 Index increment. 96 97 offset: integer 98 Starting index. 99 100 Returns 101 ------- 102 out: number 103 The variance. 104 105 Examples 106 -------- 107 // Standard Usage: 108 > var x = new {{alias:@stdlib/array/float32}}( [ 1.0, -2.0, NaN, 2.0 ] ); 109 > {{alias}}.ndarray( x.length, 1, x, 1, 0 ) 110 ~4.3333 111 112 // Using offset parameter: 113 > var x = new {{alias:@stdlib/array/float32}}( [ 1.0, -2.0, 3.0, 2.0, 5.0, -1.0 ] ); 114 > var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 ); 115 > {{alias}}.ndarray( N, 1, x, 2, 1 ) 116 ~4.3333 117 118 See Also 119 -------- 120