R application to compute t-test between populations
The package mypackage runs t-test on two populations to determine whether we should reject the NULL of equality of means at the alpha level of significance.
myttest takes in two populations of data x and y as a numeric vector, a Boolean argument if paired, and an alpha value. The function then runs the appropriate form of the t-test and returns all relevant information in an Rttest object.
Rttest.print is a print function for Rttest objects that prints several information from the t-test result.
Rttest.plot is a plot function for Rttest objects that plots boxplots. It creates boxplots of the data when non-paired data is analyzed. It also will make a boxplot of differences in data when paired = TRUE.
In this package we will be using S3 OOP -- which is the commonly used object oriented form in R package making.
See https://adv-r.hadley.nz/s3.html for more information.
There are two forms of documentation
- Function specific using Roxygen.
- Vignette -- long form.
The first function is myttest. This function computes a t-test and produces a named list of useful information, including the data, type of t-test used, confidence interval, etc.
a <- rnorm(40, 20, 10)
b <- rnorm(30, 10, 12)
out <- myttest(x=a, y=b, paired = FALSE)
class(out)
Notice that the output is of class r class(out)
The function returns a list of components:
names(out)
The components can then be operated on by an appropriate method attached to a generic.
The methods are attached to the generic function print() and plot()
We can call it by simply invoking the print() function
print(out)
We can call it by simply invoking the plot() function
plot(out)