Normality Tester

Q-Q plots of randomly generated normal data of the same samplesize as the tested data are generated and ploted on the perimeter of the graph while a Q-Q plot of the actual data is depicted in the center of the graph.

ntester(actual.data)

Arguments

actual.data	is a numeric vector. Missing and infinite values are allowed, but are ignored in the calculation. The length of actual.data must be less than 5000 after dropping nonfinite values.

Details

Q-Q plots of randomly generated normal data of the same size as the tested data are generated and ploted on the perimeter of the graph sheet while a Q-Q plot of the actual data is depicted in the center of the graph. The p-values are calculated based on the Shapiro-Wilk W-statistic. Function will only work on numeric vectors containing less than or equal to 5000 observations.

References

Shapiro, S.S. and Wilk, M.B. (1965). An analysis of variance test for normality (complete samples). Biometrika 52: 591-611.

Examples

ntester(rexp(50,1))
    # Q-Q plot of random exponential data in center plot
    # surrounded by 8 Q-Q plots of randomly generated
    # standard normal data of size 50.