modeval (version 0.1.3)

suggest_transformation: Plot Skewness and Kurtosis and suggest transformations

Description

suggest_transformation Evaluate the normality of the data by calculating skew and kurtosis. The user is provided guidance regarding whether data tranformation is advised, and how well each of three tranformation options (Box-Cox, Yeo-Johnson, or PCA) does in reducing non-normality as compared to each other and the original, untransformed data set.

Usage

suggest_transformation(x)

Arguments

x

A dataframe of input variables.

Value

Four plots depicting skew and kurtosis of each variable. The four plots are (1) the original, untransformed data, (2) transformed data applying Box-Cox (tagged "tf1"), (3) tranformed data applying Yeo-Johnson (tagged applying "tf2"), and (4) transformed data using Principal Components (tagged "tf3"). Additionally, the three transformed data sets generated and ready to be called with other functions using the tags.

Examples

## Not run: ------------------------------------
# library(mlbench)
# data(PimaIndiansDiabetes)
# index <- sample(seq_len(nrow(PimaIndiansDiabetes)), 500)
# trainingSet <- PimaIndiansDiabetes[index, ]
# testSet <- PimaIndiansDiabetes[-index, ]
# x <- trainingSet[, -9]
# y <- trainingSet[, 9]
# x_test <- testSet[, -9]
# y_test <- testSet[, 9]
# suggest_transformation(x)
# 
# # vignette("modeval") #check a vignette for further details
## ---------------------------------------------