getpar: Function to calculate the parameter that specifies the...

Description Usage Arguments Details Value Author(s) References See Also Examples

Description

This function calculates the parameter that specifies the conditional error function running through a given point (p1,p2), based on a chosen family of conditional error functions.

Usage

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getpar(typ, p1 = NA, p2 = p1, c = FALSE)

Arguments

typ

type of test: "b" for Bauer and Koehne (1994), "l" for Lehmacher and Wassmer (1999), "v" for Vandemeulebroecke (2006) and "h" for the horizontal conditional error function

p1

the p-value p1 of the test after the first stage

p2

the p-value p2 of the test after the second stage, defaults to p1

c

logical determining whether the parameter alpha2 or the parameter c is returned (alpha2 is the default).

Details

See parconv for more information on the two alternative parameterizations by alpha2 and c.

Value

getpar returns the parameter (either alpha2 or c, depending on the chosen parameterization) that specifies the conditional error function running through (p1,p2).

Author(s)

Marc Vandemeulebroecke

References

Bauer, P., Koehne, K. (1994). Evaluation of experiments with adaptive interim analyses. Biometrics 50, 1029-1041.

Lehmacher, W., Wassmer, G. (1999). Adaptive sample size calculations in group sequential trials. Biometrics 55, 1286-1290.

Vandemeulebroecke, M. (2006). An investigation of two-stage tests. Statistica Sinica 16, 933-951.

See Also

adaptTest package description, parconv, CEF

Examples

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## Plot the conditional error function of the Lehmacher-Wassmer (1999) type that runs through (p1,p2)=(0.3,0.7)
alpha2 <- getpar(typ="l", p1=0.3, p2=0.7)
plotCEF(typ="l", a2=alpha2, add=FALSE)

## Other ways of doing the same as above
plotCEF(typ="l", p1=0.3, p2=0.7, add=FALSE) 
plot(CEF(typ="l", p1=0.3, p2=0.7), xlim=0:1)

adaptTest documentation built on May 29, 2017, 8:29 p.m.