Testing Functions in R


Today I have created a custom function to find the mean of a given data frame, I have also compared the results with the inbuild R function "mean". 

Theoretically “A function is defined by an assignment of the form.

 > name <- function (arg_1, arg_2, ...) expression

This expression is used to calculate a value. Value of the expression is the value returned for the function”.(Venables et al., 2022)

Using this expression and formula for the mean which is defined by the sum of the digits divided by the total number of digits,

I understood that mean function can be expressed as

myMean <- function(assignment2{return(sum(assignment2)/length(assignment2))}

R usually has already existing functions in its programming language. For example, adding values to the environment and then calling for mean. Using command mean(assignment2) is enough to get the result. But, in case if R doesn't have inbuilt designated tasks, then it can be carried out by defining every single task in the formula. Like defining values such as

length which includes the total number of digits we want to add and sum which is the addition of the digits. So, the Mean can be obtained by calling the other two values we defined, like sum/length.

Data Frame:

>assignment2 <- c(16, 18, 14, 22, 27, 17, 19, 17, 17, 22, 20, 22)

 

Inbuilt designated tasks:

When I implemented this code, I got mean as

 

>assignment2 <- c (16, 18, 14, 22, 27, 17, 19, 17, 17, 22, 20, 22)
>mean(assignment2)
[1] 19.25

 

If the inbuilt designated task is absent:

> assignment2 <- c(16, 18, 14, 22, 27, 17, 19, 17, 17, 22, 20, 22)
> myMean <- function(assignment2){return(sum(assignment2)/length(assignment2))}
> myMean(assignment2)
[1] 19.25

 

I have also implemented this code to get mean:(University of Florida, 2007)

>assignment2 <- c(16, 18, 14, 22, 27, 17, 19, 17, 17, 22, 20, 22)
>s=sum(assignment2)
>n=length(assignment2)
>myMean(assignment2)<- function(assignment2){return(s/n)}
>myMean(assignment2)

When I implemented this code, I got mean as 

[1] 19.25
 

Through this experiment, I see that the mean has been calculated accurately through the function created for calculating the mean.

 URL to git repo:https://github.com/VedaVangala/vedas-r-repo/tree/main/Module%202


References


Venables,W.N., Smith,D.M., & R core team.(2022).An Introduction to R(Version 4.2.2).

URL: https://cran.r-project.org/doc/manuals/r-release/R-intro.pdf

University of Florida. (2007). Writing Functions Using R.

URL: http://media.news.health.ufl.edu/misc/bolt/Software_R/docs/03_WorkingWithFunctions.pdf 

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