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## Overview

This package includes functions that I find useful for teaching statistics as well as actually practicing the art. They typically are not “new” methods but rather wrappers around either base R or other packages and concepts I’m trying to master. Currently contains:

• Plot2WayANOVA which as the name implies conducts a 2 way ANOVA and plots the results using ggplot2
• neweta which is a helper function that appends the results of a Type II eta squared calculation onto a classic ANOVA table
• Mode which finds the modal value in a vector of data
• SeeDist which wraps around ggplot2 to provide visualizations of univariate data.
• OurConf is a simulation function that helps you learn about confidence intervals

## Installation

# Install from CRAN
install.packages("CGPfunctions")

# Highly recommended since it is under rapid development right now
# Or the development version from GitHub
# install.packages("devtools")
devtools::install_github("ibecav/CGPfunctions")


## Usage

library(CGPfunctions) will load the package which contains 5 functions:

SeeDist will give you some plots of the distribution of a variable using ggplot2

library(CGPfunctions)
SeeDist(mtcars$hp,whatvar="Horsepower",whatplots="d")  #> Min. 1st Qu. Median Mean 3rd Qu. Max. #> 52.0 96.5 123.0 146.7 180.0 335.0  Mode is a helper function that simply returns one or more modal values Mode(mtcars$hp)
#> [1] 110 175 180


neweta is a helper function which returns a tibble containing AOV output similar to summary(aov(MyAOV)) but with eta squared computed and appended as an additional column

MyAOV <- aov(mpg~am*cyl, mtcars)
neweta(MyAOV)
#> # A tibble: 4 x 8
#>   Source       Df Sum Sq Mean Sq F value       p sigstars eta sq
#>   <fct>     <int>    <dbl>     <dbl>     <dbl>   <dbl> <chr>       <dbl>
#> 1 am            1     37.0     37.0       4.30  0.0480 *          0.0330
#> 2 cyl           1    450.     450.       52.0   0.     ***        0.399
#> 3 am:cyl        1     29.4     29.4       3.40  0.0760 .          0.0260
#> 4 Residuals    28    242.       8.64     NA    NA      <NA>       0.215


The Plot2WayANOVA function conducts a classic analysis using existing R functions and packages in a sane and defensible manner not necessarily in the one and only manner.

Plot2WayANOVA(mpg~am*cyl, mtcars)
#>
#> Converting am to a factor --- check your results
#>
#> Converting cyl to a factor --- check your results
#>
#> You have an unbalanced design. Using Type II sum of squares, eta squared may not sum to 1.0
#> # A tibble: 4 x 8
#>   Source       Df Sum Sq Mean Sq F value       p sigstars eta sq
#>   <fct>     <int>    <dbl>     <dbl>     <dbl>   <dbl> <chr>       <dbl>
#> 1 am            1     36.8     36.8       4.00  0.0560 .          0.0330
#> 2 cyl           2    456.     228.       24.8   0.     ***        0.405
#> 3 am:cyl        2     25.4     12.7       1.40  0.269  ""         0.0230
#> 4 Residuals    26    239.       9.19     NA    NA      <NA>       0.212
#>
#> Table of group means
#> # A tibble: 6 x 9
#> # Groups:   am [2]
#>   am    cyl   TheMean TheSD TheSEM CIMuliplier LowerBound UpperBound     N
#>   <fct> <fct>   <dbl> <dbl>  <dbl>       <dbl>      <dbl>      <dbl> <int>
#> 1 0     4        22.9 1.45   0.839        4.30       19.3       26.5     3
#> 2 0     6        19.1 1.63   0.816        3.18       16.5       21.7     4
#> 3 0     8        15.0 2.77   0.801        2.20       13.3       16.8    12
#> 4 1     4        28.1 4.48   1.59         2.36       24.3       31.8     8
#> 5 1     6        20.6 0.751  0.433        4.30       18.7       22.4     3
#> 6 1     8        15.4 0.566  0.400       12.7        10.3       20.5     2
#>
#> Testing Homogeneity of Variance with Brown-Forsythe
#>    *** Possible violation of the assumption ***
#> Levene's Test for Homogeneity of Variance (center = median)
#>       Df F value  Pr(>F)
#> group  5   2.736 0.04086 *
#>       26
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#>
#> Testing Normality Assumption with Shapiro-Wilk
#>
#>  Shapiro-Wilk normality test
#>
#> data:  MyAOV_residuals
#> W = 0.96277, p-value = 0.3263
#>
#> Interaction graph plotted...


OurConf is a simulation function that helps you learn about confidence intervals

OurConf(samples = 20, n = 15, mu = 100, sigma = 20, conf.level = 0.90)


#> 100 % of the confidence intervals contain Mu = 100 .


## Credits

Many thanks to Dani Navarro and the book > (Learning Statistics with R) whose etaSquared function was the genesis of neweta.

“He who gives up safety for speed deserves neither.” (via)

#### A shoutout to some other packages I find essential.

• stringr, for strings.
• lubridate, for date/times.
• forcats, for factors.
• haven, for SPSS, SAS and Stata files.
• readxl, for .xls and .xlsx files.
• modelr, for modelling within a pipeline
• broom, for turning models into tidy data
• ggplot2, for data visualisation.
• dplyr, for data manipulation.
• tidyr, for data tidying.
• purrr, for functional programming.
• tibble, for tibbles, a modern re-imagining of data frames.

## Leaving Feedback

If you like CGPfunctions, please consider leaving feedback here.

## Contributing

Contributions in the form of feedback, comments, code, and bug reports are most welcome. How to contribute:

• Issues, bug reports, and wish lists: File a GitHub issue.
• Contact the maintainer ibecav at gmail.com by email.