mctp {nparcomp}R Documentation

Nonparam. multiple contrast tests and simult. confidence intervals

Description

The function mctp computes the estimator of nonparametric relative effects based on global rankings, simultaneous confidence intervals for the effects and adjusted p-values based on special contrasts like "Tukey", "Dunnett", "Sequen", "Williams", "Changepoint", "AVE", "McDermott", "Marcus", "UmbrellaWilliams", "UserDefined". The statistics are computed using multivariate normal distribution, multivariate Satterthwaite t-Approximation and multivariate transformations (Fisher function). The function 'mctp' also computes one-sided and two-sided confidence intervals and p-values. The confidence intervals can be plotted.

Usage

mctp(formula, data, type = c("Tukey", "Dunnett", "Sequen", 
     "Williams", "Changepoint", "AVE", "McDermott", "Marcus", 
     "UmbrellaWilliams", "UserDefined"), conf.level = 0.95, 
     alternative = c("two.sided", "less", "greater"), 
     asy.method = c("fisher", "mult.t", "normal"),
     plot.simci = FALSE, control = NULL, info = TRUE, rounds = 3, 
     contrast.matrix = NULL, correlation = FALSE, 
     effect=c("unweighted","weighted"))

Arguments

formula

A two-sided 'formula' specifying a numeric response variable and a factor with more than two levels. If the factor contains less than 3 levels, an error message will be returned.

data

A dataframe containing the variables specified in formula.

type

Character string defining the type of contrast. It should be one of "Tukey", "Dunnett", "Sequen", "Williams", "Changepoint", "AVE", "McDermott", "Marcus", "UmbrellaWilliams", "UserDefined".

conf.level

The confidence level for conflevel-confidence intervals (default is 0.95).

alternative

Character string defining the alternative hypothesis, one of "two.sided", "less" or "greater".

asy.method

Character string defining the asymptotic approximation method, one of "mult.t" for using a multivariate t-distribution with a Satterthwaite Approximation, "fisher" for using the Fisher transformation function, "normal", for using the multivariate normal distribution.

plot.simci

A logical indicating whether you want a plot of the confidence intervals.

control

Character string defining the control group in Dunnett comparisons. By default it is the first group by definition of the factor variable.

info

A logical whether you want a brief overview with informations about the output.

rounds

Number of rounds for the numeric values of the output (default is 3).

contrast.matrix

User defined contrast matrix.

correlation

A logical whether the estimated correlation matrix and covariance matrix should be printed.

effect

Character string defining the type of effect, one of "unweighted" and "weighted".

Value

Data.Info

List of samples and sample sizes and estimated effect per group.

Contrast

Contrast matrix.

Analysis

Estimator: Estimated relative effect, Lower: Lower limit of the simultaneous confidence interval, Upper: Upper limit of the simultaneous confidence interval, Statistic: Teststatistic p.Value: Adjusted p-values for the hypothesis by the choosen approximation method.

input

List of input by user.

Note

If the samples are completely seperated the variance estimators are Zero by construction. In these cases the Null-estimators are replaced by 0.001. Estimated relative effects with 0 or 1 are replaced with 0.001, 0.999 respectively.

A summary and a graph can be created separately by using the functions summary.mctp and plot.mctp.

For the analysis, the R packages 'multcomp' and 'mvtnorm' are required.

Author(s)

Frank Konietschke

References

F. Konietschke, L.A. Hothorn, E. Brunner: Rank-Based Multiple Test Procedures and Simultaneous Confidence Intervals. Electronic Journal of Statistics, Vol.0 (2011) 1-8.

Konietschke, F., Placzek, M., Schaarschmidt, S., Hothorn, L.A. (2014). nparcomp: An R Software Package for Nonparametric Multiple Comparisons and Simultaneous Confidence Intervals. Journal of Statistical Software, 61(10), 1-17.

See Also

For simultaneous confidence intervals for relative contrast effects, see nparcomp.

Examples


data(liver)

  # Williams Contrast

a<-mctp(weight ~dosage, data=liver, asy.method = "fisher",
        type = "Williams", alternative = "two.sided", 
        plot.simci = TRUE, info = FALSE)
summary(a)

 # Dunnett Contrast

b<-mctp(weight ~dosage, data=liver, asy.method = "fisher",
        type = "Dunnett", alternative = "two.sided", 
        plot.simci = TRUE, info = FALSE)
summary(b)

 # Dunnett dose 3 is baseline

c<-mctp(weight ~dosage, data=liver, asy.method = "fisher",
        type = "Dunnett", control = "3",alternative = "two.sided",
        plot.simci = TRUE, info = FALSE)
summary(c)


data(colu)

  # Tukey comparison- one sided(less)

a<-mctp(corpora~ dose, data=colu, asy.method = "mult.t",
        type = "Tukey",alternative = "less", 
        plot.simci = TRUE, info = FALSE)
summary(a)

 # Tukey comparison- one sided(greater)

b<-mctp(corpora~ dose, data=colu, asy.method = "mult.t",
        type = "Tukey",alternative = "greater", 
        plot.simci = TRUE, info = FALSE)
summary(b)

  # Tukey comparison- one sided(less)

c<-mctp(corpora~ dose, data=colu, asy.method = "mult.t",
        type = "Tukey",alternative = "less", 
        plot.simci = TRUE, info = FALSE)
summary(c)

 # Marcus comparison- one sided(greater)

d<-mctp(corpora~ dose, data=colu, asy.method = "fisher",
        type = "Marcus",alternative = "greater", 
        plot.simci = TRUE, info = FALSE)
summary(d)

[Package nparcomp version 2.6 Index]