In UBC-MDS/Rcat: a collection of EDA related functions

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Rcat

R package to simplify and ease EDA process

Creators: Netanel Barasch, Eithar Elbasheer, Yingping Qian, Hanying Zhang

Package page: https://ubc-mds.github.io/Rcat
Package Vigenette: https://ubc-mds.github.io/Rcat/articles/Rcat-vignette.html

Project Overview

Rcat is a package that provides a collection of convenient functions for Exploratory Data Analysis (EDA). In the early stage of a data science project, EDA is a crucial stage to perform an initial investigation on the dataset and inspire valuable research questions. This package simplifies the process of detecting and dealing with missing and suspicious values, as well as finding the relevant features.

Functions

The following 4 functions are included in our package.

1. misscat: This function drops the rows which has missing values that exceeded the minimum missing values threshold.

2. suscat: Datasets could include erroneous values such as outliers. This function detects suspected erroneous numeric data in user-chosen columns.

3. repwithna: Datasets could include uninformative strings, such as strings with only symbols or blank strings. This function replaces these strings with NAs.

4. topcorr: This function calculates the correlation between the columns and generates a list of top-correlated features in the dataset.

How Rcat fit in the R ecosystem

There are several existing packages in R that implement similar functionality.

• SmartEDA
  This package generates descriptive statistics and visualisations for data frames. A HTML EDA report is also avaliable.

• DataExplorer
  This package can analyze and visualize each variable in a data frame. It also includes common data processing methods for wrangling.

• inspectdf
  This package offers columnwise summary, comparison and visualisation of data frames.

These packages all provide functions reporting missing values and correlations. Only SmartEDA has a function that runs univariate outlier analysis. And to deal with missing values, only DataExplorer has a function to set all missing values to indicated value.

Thus in R ecosystem, there are many well-defined packages with useful functions for EDA, but there is yet no package containing these different EDA methods. With our package, we hope to incorporate these functions to help the users deal with missing values, outliers and correlations with one simplest way when they are exploring the data set.

Installation

You can install the development version of Rcat from GitHub with:

# install.packages("devtools")
devtools::install_github("UBC-MDS/Rcat")

Usage

The examples used below are based on iris from R's build in datasets. For demo purpose, we will insert some missing and erroneous values into this dataset.

iris_df <- head(iris, 5)
iris_df[1, 1:3] <- NA
iris_df[5, 2] <- NA
levels(iris_df$Species) <- c(levels(iris_df$Species), "")
iris_df[3, 5] <- ""

The example dataframe is shown below:

|Sepal.Length|Sepal.Width|Petal.Length|Petal.Width|Species| |---|---|---|---|---| |NA |NA |NA |0.2|setosa| |4.9|3.0 |1.4 |0.2|setosa| |4.7 |3.2 |1.3 |0.2|| |4.6 |3.1|1.5|0.2|setosa| |5.0 |NA|1.4|0.2|setosa|

1. misscat

Arguments

• df, the input data frame (data.frame)
• threshold, ratio of minimum missing values to drop the row (numeric)

Returns

• a dataframe after dropping rows (data.frame)

Examples

library(Rcat)
misscat(df=iris_df, threshold=0.5)

The expected output is shown below:

|Sepal.Length|Sepal.Width|Petal.Length|Petal.Width|Species| |---|---|---|---|---| |4.9|3.0 |1.4 |0.2|setosa| |4.7 |3.2 |1.3 |0.2|| |4.6 |3.1|1.5|0.2|setosa| |5.0 |NA|1.4|0.2|setosa|

2. suscat

suscat(df, columns, n = 1, num = 'percent')

Arguments

• df, the input data frame (data.frame)
• columns, vector like with names of columns to test (vector)
• n, an integer value for amount of suspected values to return
• num, the optional parameter specifies the whether n is a number of rows or percentage

Returns

• list of named vectors containing row numbers per column

Examples

library(Rcat)
suscat(iris, c("Sepal.Length"))

The expected output is shown below:

$Sepal.Length [1] 9 14 39 43 132

3. repwithna

Arguments

• df, the input data frame (data.frame)
• rmvsym, boolean value (default is FALSE), if TRUE, strings with only symbols in the data frame will be replaced as NA
• format, A regular expression representing the format of the string value in the data frame

Returns

• a dataframe after replacing uninformative string with NA (data.frame)

Examples

library(Rcat)
repwithna(df=iris_df)

The expected output is shown below:

|Sepal.Length|Sepal.Width|Petal.Length|Petal.Width|Species| |---|---|---|---|---| |NA |NA |NA |0.2|setosa| |4.9|3.0 |1.4 |0.2|setosa| |4.7 |3.2 |1.3 |0.2|NA| |4.6 |3.1|1.5|0.2|setosa| |5.0 |NA|1.4|0.2|setosa|

4. topcorr

Arguments

• df, the input data frame (data.frame)
• k, the number of feature pairs to return (intger or string, default: "all")

Returns

• a sorted pearson correlation data frame with top k correlated feature pairs (data.frame)

Examples

library(Rcat)
topcorr(df=iris, 2)

Note: Some columns in iris_df have zero standard deviation. We will use the full iris dataset for demostration.

The expected output is shown below:

|Feature 1|Feature 2|Absolute Correlation| |---|---|---| |Petal.Width|Petal.Length|0.9629| |Petal.Length|Sepal.Length|0.8718|

UBC-MDS/Rcat documentation built on March 30, 2020, 11:43 p.m.