repl.txt (2484B)
1 2 {{alias}}( x, y[, options] ) 3 Computes a two-sample F-test for equal variances. 4 5 The returned object comes with a `.print()` method which when invoked will 6 print a formatted output of the results of the hypothesis test. 7 8 Parameters 9 ---------- 10 x: Array<number> 11 First data array. 12 13 y: Array<number> 14 Second data array. 15 16 options: Object (optional) 17 Options. 18 19 options.alpha: number (optional) 20 Number in the interval `[0,1]` giving the significance level of the 21 hypothesis test. Default: `0.05`. 22 23 options.alternative: string (optional) 24 Either `two-sided`, `less` or `greater`. 25 26 options.ratio: number (optional) 27 Positive number denoting the ratio of the two population variances under 28 the null hypothesis. Default: `1`. 29 30 Returns 31 ------- 32 out: Object 33 Test result object. 34 35 out.alpha: number 36 Used significance level. 37 38 out.rejected: boolean 39 Test decision. 40 41 out.pValue: number 42 p-value of the test. 43 44 out.statistic: number 45 Value of test statistic. 46 47 out.ci: Array<number> 48 1-alpha confidence interval for the ratio of variances. 49 50 out.nullValue: number 51 Assumed ratio of variances under H0. 52 53 out.xvar: number 54 Sample variance of `x`. 55 56 out.yvar: number 57 Sample variance of `y`. 58 59 out.alternative: string 60 Alternative hypothesis (`two-sided`, `less` or `greater`). 61 62 out.dfX: number 63 Numerator degrees of freedom. 64 65 out.dfY: number 66 Denominator degrees of freedom. 67 68 out.method: string 69 Name of test. 70 71 out.print: Function 72 Function to print formatted output. 73 74 Examples 75 -------- 76 > var x = [ 610, 610, 550, 590, 565, 570 ]; 77 > var y = [ 560, 550, 580, 550, 560, 590, 550, 590 ]; 78 > var out = {{alias}}( x, y ) 79 { 80 rejected: false, 81 pValue: ~0.399, 82 statistic: ~1.976, 83 ci: [ ~0.374, ~13.542 ], 84 // ... 85 } 86 87 // Print table output: 88 > var table = out.print() 89 F test for comparing two variances 90 91 Alternative hypothesis: True ratio in variances is not equal to 1 92 93 pValue: 0.3992 94 statistic: 1.976 95 variance of x: 617.5 (df of x: 5) 96 variance of y: 312.5 (df of y: 7) 97 95% confidence interval: [0.3739,13.5417] 98 99 Test Decision: Fail to reject null in favor of alternative at 5% 100 significance level 101 102 See Also 103 -------- 104