An Example Dialog for t Tests

Description

An example of writing a dialog box for an R function.

Usage

menu.ttest()
menu.ttest2()
menu.ttest3()

Value

This just calls t.test and returns its value for printing by print.htest.

Note

The purpose of this function is to exemplify GUI programming. See the source C code for the details. The three functions differ in the way they return the information. menu.ttest returns the values of the fields etc for assembly in R code. menu.ttest2 submits a string directly to the console. menu.ttest3 returns the parsed and evaluated expression as an R object.

Examples

## The functions are currently defined as
menu.ttest <- function () 
{
    z <- .C("menu_ttest", vars = character(2), ints = integer(4), 
            level = double(1))
    ## check for cancel button
    if (z$ints[4] > 1) return(invisible())
    ## do it this way to get named variables in the answer
    oc <- call("t.test", x = as.name(z$vars[1]), y = as.name(z$vars[2]), 
               alternative = c("two.sided", "less", "greater")[z$ints[1]], 
               paired = z$ints[2] != 0, var.equal = z$ints[3] != 0, 
               conf.level = z$level)
    eval(oc)
}

menu.ttest2 <- function()
{
    .C("menu_ttest2")
    return(invisible())
}

menu.ttest3 <- function() .Call("menu_ttest3")