After you have acquired the data, you should do the following:

- Diagnose data quality.
- If there is a problem with data quality,
- The data must be corrected or re-acquired.

**Explore data to understand the data and find scenarios for performing the analysis.**- Derive new variables or perform variable transformations.

The dlookr package makes these steps fast and easy:

- Performs an data diagnosis or automatically generates a data diagnosis report.
**Discover data in a variety of ways, and automatically generate EDA(exploratory data analysis) report.**- Impute missing values and outliers, resolve skewed data, and categorize continuous variables into categorical variables. And generates an automated report to support it.

This document introduces **EDA(Exploratory Data Analysis)** methods provided by the dlookr package. You will learn how to EDA of `tbl_df`

data that inherits from data.frame and `data.frame`

with functions provided by dlookr.

dlookr increases synergy with `dplyr`

. Particularly in data exploration and data wrangle, it increases the efficiency of the `tidyverse`

package group.

Data diagnosis supports the following data structures.

- data frame : data.frame class.
- data table : tbl_df class.
**table of DBMS**: table of the DBMS through tbl_dbi.**Use dplyr as the back-end interface for any DBI-compatible database.**

To illustrate the basic use of EDA in the dlookr package, I use a `Carseats`

dataset. `Carseats`

in the `ISLR`

package is a simulated data set containing sales of child car seats at 400 different stores. This data is a data.frame created for the purpose of predicting sales volume.

```
library(ISLR)
str(Carseats)
'data.frame': 400 obs. of 11 variables:
$ Sales : num 9.5 11.22 10.06 7.4 4.15 ...
$ CompPrice : num 138 111 113 117 141 124 115 136 132 132 ...
$ Income : num 73 48 35 100 64 113 105 81 110 113 ...
$ Advertising: num 11 16 10 4 3 13 0 15 0 0 ...
$ Population : num 276 260 269 466 340 501 45 425 108 131 ...
$ Price : num 120 83 80 97 128 72 108 120 124 124 ...
$ ShelveLoc : Factor w/ 3 levels "Bad","Good","Medium": 1 2 3 3 1 1 3 2 3 3 ...
$ Age : num 42 65 59 55 38 78 71 67 76 76 ...
$ Education : num 17 10 12 14 13 16 15 10 10 17 ...
$ Urban : Factor w/ 2 levels "No","Yes": 2 2 2 2 2 1 2 2 1 1 ...
$ US : Factor w/ 2 levels "No","Yes": 2 2 2 2 1 2 1 2 1 2 ...
```

The contents of individual variables are as follows. (Refer to ISLR::Carseats Man page)

- Sales
- Unit sales (in thousands) at each location

- CompPrice
- Price charged by competitor at each location

- Income
- Community income level (in thousands of dollars)

- Advertising
- Local advertising budget for company at each location (in thousands of dollars)

- Population
- Population size in region (in thousands)

- Price
- Price company charges for car seats at each site

- ShelveLoc
- A factor with levels Bad, Good and Medium indicating the quality of the shelving location for the car seats at each site

- Age
- Average age of the local population

- Education
- Education level at each location

- Urban
- A factor with levels No and Yes to indicate whether the store is in an urban or rural location

- US
- A factor with levels No and Yes to indicate whether the store is in the US or not

When data analysis is performed, data containing missing values is frequently encountered. However, ‘Carseats’ is complete data without missing values. So the following script created the missing values and saved them as `carseats`

.

```
<- ISLR::Carseats
carseats
suppressWarnings(RNGversion("3.5.0"))
set.seed(123)
sample(seq(NROW(carseats)), 20), "Income"] <- NA
carseats[
suppressWarnings(RNGversion("3.5.0"))
set.seed(456)
sample(seq(NROW(carseats)), 10), "Urban"] <- NA carseats[
```

dlookr can help to understand the distribution of data by calculating descriptive statistics of numerical data. In addition, correlation between variables is identified and normality test is performed. It also identifies the relationship between target variables and independent variables.:

The following is a list of the EDA functions included in the dlookr package.:

`describe()`

provides descriptive statistics for numerical data.`normality()`

and`plot_normality()`

perform normalization and visualization of numerical data.`correlate()`

and`plot_correlate()`

calculate the correlation coefficient between two numerical data and provide visualization.`target_by()`

defines the target variable and`relate()`

describes the relationship with the variables of interest corresponding to the target variable.`plot.relate()`

visualizes the relationship to the variable of interest corresponding to the destination variable.`eda_report()`

performs an exploratory data analysis and reports the results.

`describe()`

`describe()`

computes descriptive statistics for numerical data. The descriptive statistics help determine the distribution of numerical variables. Like function of dplyr, the first argument is the tibble (or data frame). The second and subsequent arguments refer to variables within that data frame.

The variables of the `tbl_df`

object returned by `describe()`

are as follows.

`n`

: number of observations excluding missing values`na`

: number of missing values`mean`

: arithmetic average`sd`

: standard deviation`se_mean`

: standard error mean. sd/sqrt(n)`IQR`

: interquartile range (Q3-Q1)`skewness`

: skewness`kurtosis`

: kurtosis`p25`

: Q1. 25% percentile`p50`

: median. 50% percentile`p75`

: Q3. 75% percentile`p01`

,`p05`

,`p10`

,`p20`

,`p30`

: 1%, 5%, 20%, 30% percentiles`p40`

,`p60`

,`p70`

,`p80`

: 40%, 60%, 70%, 80% percentiles`p90`

,`p95`

,`p99`

,`p100`

: 90%, 95%, 99%, 100% percentiles

For example, `describe()`

can computes the statistics of all numerical variables in `carseats`

:

```
describe(carseats)
# A tibble: 8 x 26
variable n na mean sd se_mean IQR skewness kurtosis p00 p01<chr> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Sales 400 0 7.50 2.82 0.141 3.93 0.186 -0.0809 0 0.906
2 CompPri… 400 0 125. 15.3 0.767 20 -0.0428 0.0417 77 89.0
3 Income 380 20 68.9 28.1 1.44 48.2 0.0449 -1.09 21 21.8
4 Adverti… 400 0 6.64 6.65 0.333 12 0.640 -0.545 0 0
# … with 4 more rows, and 15 more variables: p05 <dbl>, p10 <dbl>, p20 <dbl>,
# p25 <dbl>, p30 <dbl>, p40 <dbl>, p50 <dbl>, p60 <dbl>, p70 <dbl>,
# p75 <dbl>, p80 <dbl>, p90 <dbl>, p95 <dbl>, p99 <dbl>, p100 <dbl>
```

`skewness`

: The left-skewed distribution data that is the variables with large positive skewness should consider the log or sqrt transformations to follow the normal distribution. The variables`Advertising`

seem to need to consider variable transformation.`mean`

and`sd`

,`se_mean`

: The`Population`

with a large`standard error of the mean`

(se_mean) has low representativeness of the`arithmetic mean`

(mean). The`standard deviation`

(sd) is much larger than the arithmetic average.

The following explains the descriptive statistics only for a few selected variables.:

```
# Select columns by name
describe(carseats, Sales, CompPrice, Income)
# A tibble: 3 x 26
variable n na mean sd se_mean IQR skewness kurtosis p00 p01<chr> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Sales 400 0 7.50 2.82 0.141 3.93 0.186 -0.0809 0 0.906
2 CompPri… 400 0 125. 15.3 0.767 20 -0.0428 0.0417 77 89.0
3 Income 380 20 68.9 28.1 1.44 48.2 0.0449 -1.09 21 21.8
# … with 15 more variables: p05 <dbl>, p10 <dbl>, p20 <dbl>, p25 <dbl>,
# p30 <dbl>, p40 <dbl>, p50 <dbl>, p60 <dbl>, p70 <dbl>, p75 <dbl>,
# p80 <dbl>, p90 <dbl>, p95 <dbl>, p99 <dbl>, p100 <dbl>
# Select all columns between year and day (include)
describe(carseats, Sales:Income)
# A tibble: 3 x 26
variable n na mean sd se_mean IQR skewness kurtosis p00 p01<chr> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Sales 400 0 7.50 2.82 0.141 3.93 0.186 -0.0809 0 0.906
2 CompPri… 400 0 125. 15.3 0.767 20 -0.0428 0.0417 77 89.0
3 Income 380 20 68.9 28.1 1.44 48.2 0.0449 -1.09 21 21.8
# … with 15 more variables: p05 <dbl>, p10 <dbl>, p20 <dbl>, p25 <dbl>,
# p30 <dbl>, p40 <dbl>, p50 <dbl>, p60 <dbl>, p70 <dbl>, p75 <dbl>,
# p80 <dbl>, p90 <dbl>, p95 <dbl>, p99 <dbl>, p100 <dbl>
# Select all columns except those from year to day (exclude)
describe(carseats, -(Sales:Income))
# A tibble: 5 x 26
variable n na mean sd se_mean IQR skewness kurtosis p00 p01<chr> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Adverti… 400 0 6.64 6.65 0.333 12 0.640 -0.545 0 0
2 Populat… 400 0 265. 147. 7.37 260. -0.0512 -1.20 10 16.0
3 Price 400 0 116. 23.7 1.18 31 -0.125 0.452 24 55.0
4 Age 400 0 53.3 16.2 0.810 26.2 -0.0772 -1.13 25 25
# … with 1 more row, and 15 more variables: p05 <dbl>, p10 <dbl>, p20 <dbl>,
# p25 <dbl>, p30 <dbl>, p40 <dbl>, p50 <dbl>, p60 <dbl>, p70 <dbl>,
# p75 <dbl>, p80 <dbl>, p90 <dbl>, p95 <dbl>, p99 <dbl>, p100 <dbl>
```

The `describe()`

function can be sorted by `left or right skewed size`

(skewness) using `dplyr`

.:

```
%>%
carseats describe() %>%
select(variable, skewness, mean, p25, p50, p75) %>%
filter(!is.na(skewness)) %>%
arrange(desc(abs(skewness)))
# A tibble: 8 x 6
variable skewness mean p25 p50 p75<chr> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Advertising 0.640 6.64 0 5 12
2 Sales 0.186 7.50 5.39 7.49 9.32
3 Price -0.125 116. 100 117 131
4 Age -0.0772 53.3 39.8 54.5 66
# … with 4 more rows
```

The `describe()`

function supports the `group_by()`

function syntax of the `dplyr`

package.

```
%>%
carseats group_by(US) %>%
describe(Sales, Income)
# A tibble: 4 x 27
variable US n na mean sd se_mean IQR skewness kurtosis p00<chr> <fct> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Income No 130 12 65.8 28.2 2.48 50 0.100 -1.14 22
2 Income Yes 250 8 70.4 27.9 1.77 48 0.0199 -1.06 21
3 Sales No 142 0 6.82 2.60 0.218 3.44 0.323 0.808 0
4 Sales Yes 258 0 7.87 2.88 0.179 4.23 0.0760 -0.326 0.37
# … with 16 more variables: p01 <dbl>, p05 <dbl>, p10 <dbl>, p20 <dbl>,
# p25 <dbl>, p30 <dbl>, p40 <dbl>, p50 <dbl>, p60 <dbl>, p70 <dbl>,
# p75 <dbl>, p80 <dbl>, p90 <dbl>, p95 <dbl>, p99 <dbl>, p100 <dbl>
```

```
%>%
carseats group_by(US, Urban) %>%
describe(Sales, Income)
# A tibble: 12 x 28
variable US Urban n na mean sd se_mean IQR skewness kurtosis<chr> <fct> <fct> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Income No No 42 4 60.2 29.1 4.49 45.2 0.408 -1.00
2 Income No Yes 84 8 69.5 27.4 2.99 47 -0.0497 -1.11
3 Income No <NA> 4 0 48.2 24.7 12.3 40.8 -0.0496 -5.70
4 Income Yes No 65 4 70.5 29.9 3.70 48 0.0736 -1.08
# … with 8 more rows, and 17 more variables: p00 <dbl>, p01 <dbl>, p05 <dbl>,
# p10 <dbl>, p20 <dbl>, p25 <dbl>, p30 <dbl>, p40 <dbl>, p50 <dbl>,
# p60 <dbl>, p70 <dbl>, p75 <dbl>, p80 <dbl>, p90 <dbl>, p95 <dbl>,
# p99 <dbl>, p100 <dbl>
```

`normality()`

`normality()`

performs a normality test on numerical data. `Shapiro-Wilk normality test`

is performed. When the number of observations is greater than 5000, it is tested after extracting 5000 samples by random simple sampling.

The variables of `tbl_df`

object returned by `normality()`

are as follows.

`statistic`

: Statistics of the Shapiro-Wilk test`p_value`

: p-value of the Shapiro-Wilk test`sample`

: Number of sample observations performed Shapiro-Wilk test

`normality()`

performs the normality test for all numerical variables of `carseats`

as follows.:

```
normality(carseats)
# A tibble: 8 x 4
vars statistic p_value sample<chr> <dbl> <dbl> <dbl>
1 Sales 0.995 2.54e- 1 400
2 CompPrice 0.998 9.77e- 1 400
3 Income 0.961 1.52e- 8 400
4 Advertising 0.874 1.49e-17 400
# … with 4 more rows
```

The following example performs a normality test on only a few selected variables.

```
# Select columns by name
normality(carseats, Sales, CompPrice, Income)
# A tibble: 3 x 4
vars statistic p_value sample<chr> <dbl> <dbl> <dbl>
1 Sales 0.995 0.254 400
2 CompPrice 0.998 0.977 400
3 Income 0.961 0.0000000152 400
# Select all columns between year and day (inclusive)
normality(carseats, Sales:Income)
# A tibble: 3 x 4
vars statistic p_value sample<chr> <dbl> <dbl> <dbl>
1 Sales 0.995 0.254 400
2 CompPrice 0.998 0.977 400
3 Income 0.961 0.0000000152 400
# Select all columns except those from year to day (inclusive)
normality(carseats, -(Sales:Income))
# A tibble: 5 x 4
vars statistic p_value sample<chr> <dbl> <dbl> <dbl>
1 Advertising 0.874 1.49e-17 400
2 Population 0.952 4.08e-10 400
3 Price 0.996 3.90e- 1 400
4 Age 0.957 1.86e- 9 400
# … with 1 more row
```

You can use `dplyr`

to sort variables that do not follow a normal distribution in order of `p_value`

:

```
library(dplyr)
%>%
carseats normality() %>%
filter(p_value <= 0.01) %>%
arrange(abs(p_value))
# A tibble: 5 x 4
vars statistic p_value sample<chr> <dbl> <dbl> <dbl>
1 Advertising 0.874 1.49e-17 400
2 Education 0.924 2.43e-13 400
3 Population 0.952 4.08e-10 400
4 Age 0.957 1.86e- 9 400
# … with 1 more row
```

In particular, the `Advertising`

variable is considered to be the most out of the normal distribution.

The `normality()`

function supports the `group_by()`

function syntax in the `dplyr`

package.

```
%>%
carseats group_by(ShelveLoc, US) %>%
normality(Income) %>%
arrange(desc(p_value))
# A tibble: 6 x 6
variable ShelveLoc US statistic p_value sample<chr> <fct> <fct> <dbl> <dbl> <dbl>
1 Income Bad No 0.969 0.470 34
2 Income Bad Yes 0.958 0.0343 62
3 Income Good No 0.902 0.0328 24
4 Income Good Yes 0.955 0.0296 61
# … with 2 more rows
```

The `Income`

variable does not follow the normal distribution. However, the case where `US`

is `No`

and `ShelveLoc`

is `Good`

and `Bad`

at the significance level of 0.01, it follows the normal distribution.

The following example performs `normality test of log(Income)`

for each combination of `ShelveLoc`

and `US`

categorical variables to search for variables that follow the normal distribution.

```
%>%
carseats mutate(log_income = log(Income)) %>%
group_by(ShelveLoc, US) %>%
normality(log_income) %>%
filter(p_value > 0.01)
# A tibble: 1 x 6
variable ShelveLoc US statistic p_value sample<chr> <fct> <fct> <dbl> <dbl> <dbl>
1 log_income Bad No 0.940 0.0737 34
```

`plot_normality()`

`plot_normality()`

visualizes the normality of numeric data.

The information visualized by `plot_normality()`

is as follows.:

`Histogram of original data`

`Q-Q plot of original data`

`histogram of log transformed data`

`Histogram of square root transformed data`

In the data analysis process, it often encounters numerical data that follows the `power-law distribution`

. Since the numerical data that follows the `power-law distribution`

is converted into a normal distribution by performing the `log`

or `sqrt`

transformation, so draw a histogram of the `log`

and `sqrt`

transformed data.

`plot_normality()`

can also specify several variables like `normality()`

function.

```
# Select columns by name
plot_normality(carseats, Sales, CompPrice)
```

The `plot_normality()`

function also supports the `group_by()`

function syntax in the `dplyr`

package.

```
%>%
carseats filter(ShelveLoc == "Good") %>%
group_by(US) %>%
plot_normality(Income)
```

`correlation coefficient`

using `correlate()`

`correlate()`

calculates the correlation coefficient of all combinations of `carseats`

numerical variables as follows:

```
correlate(carseats)
# A tibble: 56 x 3
var1 var2 coef_corr<fct> <fct> <dbl>
1 CompPrice Sales 0.0641
2 Income Sales 0.151
3 Advertising Sales 0.270
4 Population Sales 0.0505
# … with 52 more rows
```

The following example performs a normality test only on combinations that include several selected variables.

```
# Select columns by name
correlate(carseats, Sales, CompPrice, Income)
# A tibble: 21 x 3
var1 var2 coef_corr<fct> <fct> <dbl>
1 CompPrice Sales 0.0641
2 Income Sales 0.151
3 Sales CompPrice 0.0641
4 Income CompPrice -0.0761
# … with 17 more rows
# Select all columns between year and day (include)
correlate(carseats, Sales:Income)
# A tibble: 21 x 3
var1 var2 coef_corr<fct> <fct> <dbl>
1 CompPrice Sales 0.0641
2 Income Sales 0.151
3 Sales CompPrice 0.0641
4 Income CompPrice -0.0761
# … with 17 more rows
# Select all columns except those from year to day (exclude)
correlate(carseats, -(Sales:Income))
# A tibble: 35 x 3
var1 var2 coef_corr<fct> <fct> <dbl>
1 Advertising Sales 0.270
2 Population Sales 0.0505
3 Price Sales -0.445
4 Age Sales -0.232
# … with 31 more rows
```

`correlate()`

produces `two pairs of variables`

. So the following example uses `filter()`

to get the correlation coefficient for `a pair of variable`

combinations:

```
%>%
carseats correlate(Sales:Income) %>%
filter(as.integer(var1) > as.integer(var2))
# A tibble: 3 x 3
var1 var2 coef_corr<fct> <fct> <dbl>
1 CompPrice Sales 0.0641
2 Income Sales 0.151
3 Income CompPrice -0.0761
```

The `correlate()`

also supports the `group_by()`

function syntax in the `dplyr`

package.

```
%>%
carseats filter(ShelveLoc == "Good") %>%
group_by(Urban, US) %>%
correlate(Sales) %>%
filter(abs(coef_corr) > 0.5)
# A tibble: 10 x 5
Urban US var1 var2 coef_corr<fct> <fct> <fct> <fct> <dbl>
1 No No Sales Population -0.530
2 No No Sales Price -0.838
3 No Yes Sales Price -0.630
4 Yes No Sales Price -0.833
# … with 6 more rows
```

`plot_correlate()`

`plot_correlate()`

visualizes the correlation matrix.

`plot_correlate(carseats)`

`plot_correlate()`

can also specify multiple variables, like the `correlate()`

function. The following is a visualization of the correlation matrix including several selected variables.

```
# Select columns by name
plot_correlate(carseats, Sales, Price)
```

The `plot_correlate()`

function also supports the `group_by()`

function syntax in the `dplyr`

package.

```
%>%
carseats filter(ShelveLoc == "Good") %>%
group_by(Urban) %>%
plot_correlate(Sales)
```

To perform EDA based on `target variable`

, you need to create a `target_by`

class object. `target_by()`

creates a `target_by`

class with an object inheriting data.frame or data.frame. `target_by()`

is similar to `group_by()`

in `dplyr`

which creates `grouped_df`

. The difference is that you specify only one variable.

The following is an example of specifying `US`

as target variable in `carseats`

data.frame.:

`<- target_by(carseats, US) categ `

Let’s perform EDA when the target variable is a categorical variable. When the categorical variable `US`

is the target variable, we examine the relationship between the target variable and the predictor.

`relate()`

shows the relationship between the target variable and the predictor. The following example shows the relationship between `Sales`

and the target variable `US`

. The predictor `Sales`

is a numeric variable. In this case, the descriptive statistics are shown for each level of the target variable.

```
# If the variable of interest is a numerical variable
<- relate(categ, Sales)
cat_num
cat_num# A tibble: 3 x 27
variable US n na mean sd se_mean IQR skewness kurtosis p00<chr> <fct> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Sales No 142 0 6.82 2.60 0.218 3.44 0.323 0.808 0
2 Sales Yes 258 0 7.87 2.88 0.179 4.23 0.0760 -0.326 0.37
3 Sales total 400 0 7.50 2.82 0.141 3.93 0.186 -0.0809 0
# … with 16 more variables: p01 <dbl>, p05 <dbl>, p10 <dbl>, p20 <dbl>,
# p25 <dbl>, p30 <dbl>, p40 <dbl>, p50 <dbl>, p60 <dbl>, p70 <dbl>,
# p75 <dbl>, p80 <dbl>, p90 <dbl>, p95 <dbl>, p99 <dbl>, p100 <dbl>
summary(cat_num)
variable US n na mean :3 No :1 Min. :142.0 Min. :0 Min. :6.823
Length:character Yes :1 1st Qu.:200.0 1st Qu.:0 1st Qu.:7.160
Class :character total:1 Median :258.0 Median :0 Median :7.496
Mode :266.7 Mean :0 Mean :7.395
Mean :329.0 3rd Qu.:0 3rd Qu.:7.682
3rd Qu.:400.0 Max. :0 Max. :7.867
Max.
sd se_mean IQR skewness :2.603 Min. :0.1412 Min. :3.442 Min. :0.07603
Min. :2.713 1st Qu.:0.1602 1st Qu.:3.686 1st Qu.:0.13080
1st Qu.:2.824 Median :0.1791 Median :3.930 Median :0.18556
Median :2.768 Mean :0.1796 Mean :3.866 Mean :0.19489
Mean :2.851 3rd Qu.:0.1988 3rd Qu.:4.077 3rd Qu.:0.25432
3rd Qu.:2.877 Max. :0.2184 Max. :4.225 Max. :0.32308
Max.
kurtosis p00 p01 p05 :-0.32638 Min. :0.0000 Min. :0.4675 Min. :3.147
Min. :-0.20363 1st Qu.:0.0000 1st Qu.:0.6868 1st Qu.:3.148
1st Qu.:-0.08088 Median :0.0000 Median :0.9062 Median :3.149
Median : 0.13350 Mean :0.1233 Mean :1.0072 Mean :3.183
Mean : 0.36344 3rd Qu.:0.1850 3rd Qu.:1.2771 3rd Qu.:3.200
3rd Qu.: 0.80776 Max. :0.3700 Max. :1.6480 Max. :3.252
Max.
p10 p20 p25 p30 :3.917 Min. :4.754 Min. :5.080 Min. :5.306
Min. :4.018 1st Qu.:4.910 1st Qu.:5.235 1st Qu.:5.587
1st Qu.:4.119 Median :5.066 Median :5.390 Median :5.867
Median :4.073 Mean :5.051 Mean :5.411 Mean :5.775
Mean :4.152 3rd Qu.:5.199 3rd Qu.:5.576 3rd Qu.:6.010
3rd Qu.:4.184 Max. :5.332 Max. :5.763 Max. :6.153
Max.
p40 p50 p60 p70 :5.994 Min. :6.660 Min. :7.496 Min. :7.957
Min. :6.301 1st Qu.:7.075 1st Qu.:7.787 1st Qu.:8.386
1st Qu.:6.608 Median :7.490 Median :8.078 Median :8.815
Median :6.506 Mean :7.313 Mean :8.076 Mean :8.740
Mean :6.762 3rd Qu.:7.640 3rd Qu.:8.366 3rd Qu.:9.132
3rd Qu.:6.916 Max. :7.790 Max. :8.654 Max. :9.449
Max.
p75 p80 p90 p95 :8.523 Min. : 8.772 Min. : 9.349 Min. :11.28
Min. :8.921 1st Qu.: 9.265 1st Qu.:10.325 1st Qu.:11.86
1st Qu.:9.320 Median : 9.758 Median :11.300 Median :12.44
Median :9.277 Mean : 9.665 Mean :10.795 Mean :12.08
Mean :9.654 3rd Qu.:10.111 3rd Qu.:11.518 3rd Qu.:12.49
3rd Qu.:9.988 Max. :10.464 Max. :11.736 Max. :12.54
Max.
p99 p100 :13.64 Min. :14.90
Min. :13.78 1st Qu.:15.59
1st Qu.:13.91 Median :16.27
Median :13.86 Mean :15.81
Mean :13.97 3rd Qu.:16.27
3rd Qu.:14.03 Max. :16.27 Max.
```

`plot()`

visualizes the `relate`

class object created by `relate()`

as the relationship between the target variable and the predictor variable. The relationship between `US`

and `Sales`

is visualized by density plot.

`plot(cat_num)`

The following example shows the relationship between `ShelveLoc`

and the target variable `US`

. The predictor variable `ShelveLoc`

is a categorical variable. In this case, it shows the `contingency table`

of two variables. The `summary()`

function performs `independence test`

on the contingency table.

```
# If the variable of interest is a categorical variable
<- relate(categ, ShelveLoc)
cat_cat
cat_cat
ShelveLoc
US Bad Good Medium34 24 84
No 62 61 135
Yes summary(cat_cat)
: xtabs(formula = formula_str, data = data, addNA = TRUE)
Callin table: 400
Number of cases : 2
Number of factorsfor independence of all factors:
Test = 2.7397, df = 2, p-value = 0.2541 Chisq
```

`plot()`

visualizes the relationship between the target variable and the predictor. The relationship between `US`

and `ShelveLoc`

is represented by a `mosaics plot`

.

`plot(cat_cat)`

Let’s perform EDA when the target variable is numeric. When the numeric variable `Sales`

is the target variable, we examine the relationship between the target variable and the predictor.

```
# If the variable of interest is a numerical variable
<- target_by(carseats, Sales) num
```

The following example shows the relationship between `Price`

and the target variable `Sales`

. The predictor variable `Price`

is a numeric variable. In this case, it shows the result of a `simple linear model`

of the `target ~ predictor`

formula. The `summary()`

function expresses the details of the model.

```
# If the variable of interest is a numerical variable
<- relate(num, Price)
num_num
num_num
:
Calllm(formula = formula_str, data = data)
:
Coefficients
(Intercept) Price 13.64192 -0.05307
summary(num_num)
:
Calllm(formula = formula_str, data = data)
:
Residuals
Min 1Q Median 3Q Max -6.5224 -1.8442 -0.1459 1.6503 7.5108
:
CoefficientsPr(>|t|)
Estimate Std. Error t value 13.641915 0.632812 21.558 <2e-16 ***
(Intercept) -0.053073 0.005354 -9.912 <2e-16 ***
Price ---
: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
Signif. codes
: 2.532 on 398 degrees of freedom
Residual standard error-squared: 0.198, Adjusted R-squared: 0.196
Multiple R-statistic: 98.25 on 1 and 398 DF, p-value: < 2.2e-16 F
```

`plot()`

visualizes the relationship between the target and predictor variables. The relationship between `Sales`

and `Price`

is visualized with a scatter plot. The figure on the left shows the scatter plot of `Sales`

and `Price`

and the confidence interval of the regression line and regression line. The figure on the right shows the relationship between the original data and the predicted values of the linear model as a scatter plot. If there is a linear relationship between the two variables, the scatter plot of the observations converges on the red diagonal line.

`plot(num_num)`

The scatter plot of the data with a large number of observations is output as overlapping points. This makes it difficult to judge the relationship between the two variables. It also takes a long time to perform the visualization. In this case, the above problem can be solved by `hexabin plot`

.

In `plot()`

, the `hex_thres`

argument provides a basis for drawing `hexabin plot`

. If the number of observations is greater than `hex_thres`

, draw a `hexabin plot`

.

The following example visualizes the `hexabin plot`

rather than the scatter plot by specifying 350 for the `hex_thres`

argument. This is because the number of observations is 400.

`plot(num_num, hex_thres = 350)`

The following example shows the relationship between `ShelveLoc`

and the target variable `Sales`

. The predictor `ShelveLoc`

is a categorical variable and shows the result of `one-way ANOVA`

of `target ~ predictor`

relationship. The results are expressed in terms of ANOVA. The `summary()`

function shows the `regression coefficients`

for each level of the predictor. In other words, it shows detailed information about `simple regression analysis`

of `target ~ predictor`

relationship.

```
# If the variable of interest is a categorical variable
<- relate(num, ShelveLoc)
num_cat
num_cat
Analysis of Variance Table
: Sales
ResponsePr(>F)
Df Sum Sq Mean Sq F value 2 1009.5 504.77 92.23 < 2.2e-16 ***
ShelveLoc 397 2172.7 5.47
Residuals ---
: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
Signif. codessummary(num_cat)
:
Calllm(formula = formula(formula_str), data = data)
:
Residuals
Min 1Q Median 3Q Max -7.3066 -1.6282 -0.0416 1.5666 6.1471
:
CoefficientsPr(>|t|)
Estimate Std. Error t value 5.5229 0.2388 23.131 < 2e-16 ***
(Intercept) 4.6911 0.3484 13.464 < 2e-16 ***
ShelveLocGood 1.7837 0.2864 6.229 1.2e-09 ***
ShelveLocMedium ---
: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
Signif. codes
: 2.339 on 397 degrees of freedom
Residual standard error-squared: 0.3172, Adjusted R-squared: 0.3138
Multiple R-statistic: 92.23 on 2 and 397 DF, p-value: < 2.2e-16 F
```

`plot()`

visualizes the relationship between the target variable and the predictor. The relationship between `Sales`

and `ShelveLoc`

is represented by a `box plot`

.

`plot(num_cat)`

dlookr provides two automated EDA reports:

- Web page-based dynamic reports can perform in-depth analysis through visualization and statistical tables.
- Static reports generated as pdf files or html files can be archived as output of data analysis.

`eda_web_report()`

`eda_web_report()`

create dynamic report for object inherited from data.frame(`tbl_df`

, `tbl`

, etc) or data.frame.

The contents of the report are as follows.:

- Overview
- Data Structures
- Data Types
- Job Informations

- Univariate Analysis
- Descriptive Statistics
- Normality Test

- Bivariate Analysis
- Compare Numerical Variables
- Compare Categorical Variables

- Multivariate Analysis
- Correlation Analysis
- Correlation Matrix
- Correlation Plot

- Correlation Analysis
- Target based Analysis
- Grouped Numerical Variables
- Grouped Categorical Variables
- Grouped Correlation

eda_web_report() generates various reports with the following arguments.

- target
- target variable

- output_file
- name of generated file.

- output_dir
- name of directory to generate report file.

- title
- title of report.

- subtitle
- subtitle of report.

- author
- author of report.

- title_color
- color of title.

- logo_img
- name of logo image file on top left.

- create_date
- The date on which the report is generated.

- theme
- name of theme for report. support “orange” and “blue”.

- sample_percent
- Sample percent of data for performing EDA.

The following script creates a EDA report for the `data.frame`

class object, `heartfailure`

.

```
%>%
heartfailure eda_web_report(target = "death_event", subtitle = "heartfailure",
output_dir = "./", output_file = "EDA.html", theme = "blue")
```

- The dynamic contents of the report is shown in the following figure.:

`eda_paged_report()`

`eda_paged_report()`

create static report for object inherited from data.frame(`tbl_df`

, `tbl`

, etc) or data.frame.

The contents of the report are as follows.:

- Overview
- Data Structures
- Job Informations

- Univariate Analysis
- Descriptive Statistics
- Numerical Variables
- Categorical Variables

- Normality Test

- Descriptive Statistics
- Bivariate Analysis
- Compare Numerical Variables
- Compare Categorical Variables

- Multivariate Analysis
- Correlation Analysis
- Correlation Coefficient Matrix
- Correlation Plot

- Correlation Analysis
- Target based Analysis
- Grouped Numerical Variables
- Grouped Categorical Variables
- Grouped Correlation

eda_paged_report() generates various reports with the following arguments.

- target
- target variable

- output_format
- report output type. Choose either “pdf” and “html”.

- output_file
- name of generated file.

- output_dir
- name of directory to generate report file.

- title
- title of report.

- subtitle
- subtitle of report.

- abstract_title
- abstract of report

- author
- author of report.

- title_color
- color of title.

- subtitle_color
- color of subtitle.

- logo_img
- name of logo image file on top left.

- cover_img
- name of cover image file on center.

- create_date
- The date on which the report is generated.

- theme
- name of theme for report. support “orange” and “blue”.

- sample_percent
- Sample percent of data for performing EDA.

The following script creates a EDA report for the `data.frame`

class object, `heartfailure`

.

```
%>%
heartfailure eda_paged_report(target = "death_event", subtitle = "heartfailure",
output_dir = "./", output_file = "EDA.pdf", theme = "blue")
```

- The cover of the report is shown in the following figure.:

- The contents of the report is shown in the following figure.:

EDA function for table of DBMS supports In-database mode that performs SQL operations on the DBMS side. If the size of the data is large, using In-database mode is faster.

It is difficult to obtain anomaly or to implement the sampling-based algorithm in SQL of DBMS. So some functions do not yet support In-database mode. In this case, it is performed in In-memory mode in which table data is brought to R side and calculated. In this case, if the data size is large, the execution speed may be slow. It supports the collect_size argument, which allows you to import the specified number of samples of data into R.

- In-database support functions
- none

- In-database not support functions
`normality()`

`plot_normality()`

`correlate()`

`plot_correlate()`

`describe()`

`eda_web_report()`

`eda_paged_report()`

Copy the `carseats`

data frame to the SQLite DBMS and create it as a table named `TB_CARSEATS`

. Mysql/MariaDB, PostgreSQL, Oracle DBMS, other DBMS are also available for your environment.

```
if (!require(DBI)) install.packages('DBI')
if (!require(RSQLite)) install.packages('RSQLite')
if (!require(dplyr)) install.packages('dplyr')
if (!require(dbplyr)) install.packages('dbplyr')
library(dplyr)
<- ISLR::Carseats
carseats sample(seq(NROW(carseats)), 20), "Income"] <- NA
carseats[sample(seq(NROW(carseats)), 5), "Urban"] <- NA
carseats[
# connect DBMS
<- DBI::dbConnect(RSQLite::SQLite(), ":memory:")
con_sqlite
# copy carseats to the DBMS with a table named TB_CARSEATS
copy_to(con_sqlite, carseats, name = "TB_CARSEATS", overwrite = TRUE)
```

Use `dplyr::tbl()`

to create a tbl_dbi object, then use it as a data frame object. That is, the data argument of all EDA function is specified as tbl_dbi object instead of data frame object.

```
# Positive values select variables
%>%
con_sqlite tbl("TB_CARSEATS") %>%
describe(Sales, CompPrice, Income)
# A tibble: 3 x 26
variable n na mean sd se_mean IQR skewness kurtosis p00 p01<chr> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Sales 400 0 7.50 2.82 0.141 3.93 0.186 -0.0809 0 0.906
2 CompPri… 400 0 125. 15.3 0.767 20 -0.0428 0.0417 77 89.0
3 Income 380 20 68.8 28.0 1.44 47.2 0.0641 -1.08 21 21.8
# … with 15 more variables: p05 <dbl>, p10 <dbl>, p20 <dbl>, p25 <dbl>,
# p30 <dbl>, p40 <dbl>, p50 <dbl>, p60 <dbl>, p70 <dbl>, p75 <dbl>,
# p80 <dbl>, p90 <dbl>, p95 <dbl>, p99 <dbl>, p100 <dbl>
# Negative values to drop variables, and In-memory mode and collect size is 200
%>%
con_sqlite tbl("TB_CARSEATS") %>%
describe(-Sales, -CompPrice, -Income, collect_size = 200)
# A tibble: 5 x 26
variable n na mean sd se_mean IQR skewness kurtosis p00 p01<chr> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Adverti… 200 0 5.88 6.07 0.429 11 0.648 -0.667 0 0
2 Populat… 200 0 255. 149. 10.6 251. 0.0241 -1.22 10 16
3 Price 200 0 114. 23.7 1.68 31.2 -0.107 1.08 24 54.9
4 Age 200 0 54.6 15.9 1.13 24 -0.245 -1.01 25 25
# … with 1 more row, and 15 more variables: p05 <dbl>, p10 <dbl>, p20 <dbl>,
# p25 <dbl>, p30 <dbl>, p40 <dbl>, p50 <dbl>, p60 <dbl>, p70 <dbl>,
# p75 <dbl>, p80 <dbl>, p90 <dbl>, p95 <dbl>, p99 <dbl>, p100 <dbl>
# Find the statistic of all numerical variables by 'ShelveLoc' and 'US',
# and extract only those with 'ShelveLoc' variable level is "Good".
%>%
con_sqlite tbl("TB_CARSEATS") %>%
group_by(ShelveLoc, US) %>%
describe() %>%
filter(ShelveLoc == "Good")
# A tibble: 16 x 28
variable ShelveLoc US n na mean sd se_mean IQR skewness<chr> <chr> <chr> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Advertising Good No 24 0 0.0417 0.204 0.0417 0 4.90
2 Advertising Good Yes 61 0 10.2 5.91 0.757 7 0.0647
3 Age Good No 24 0 52.3 17.2 3.52 26 -0.158
4 Age Good Yes 61 0 52.7 14.8 1.90 22 -0.136
# … with 12 more rows, and 18 more variables: kurtosis <dbl>, p00 <dbl>,
# p01 <dbl>, p05 <dbl>, p10 <dbl>, p20 <dbl>, p25 <dbl>, p30 <dbl>,
# p40 <dbl>, p50 <dbl>, p60 <dbl>, p70 <dbl>, p75 <dbl>, p80 <dbl>,
# p90 <dbl>, p95 <dbl>, p99 <dbl>, p100 <dbl>
# extract only those with 'Urban' variable level is "Yes",
# and find 'Sales' statistics by 'ShelveLoc' and 'US'
%>%
con_sqlite tbl("TB_CARSEATS") %>%
filter(Urban == "Yes") %>%
group_by(ShelveLoc, US) %>%
describe(Sales)
# A tibble: 6 x 28
variable ShelveLoc US n na mean sd se_mean IQR skewness<chr> <chr> <chr> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Sales Bad No 23 0 5.36 1.91 0.398 2.32 -0.275
2 Sales Bad Yes 50 0 5.54 2.57 0.364 3.74 0.216
3 Sales Good No 18 0 9.21 2.97 0.700 3.71 0.0291
4 Sales Good Yes 37 0 10.9 2.37 0.389 3.41 -0.0714
# … with 2 more rows, and 18 more variables: kurtosis <dbl>, p00 <dbl>,
# p01 <dbl>, p05 <dbl>, p10 <dbl>, p20 <dbl>, p25 <dbl>, p30 <dbl>,
# p40 <dbl>, p50 <dbl>, p60 <dbl>, p70 <dbl>, p75 <dbl>, p80 <dbl>,
# p90 <dbl>, p95 <dbl>, p99 <dbl>, p100 <dbl>
```

```
# Test all numerical variables by 'ShelveLoc' and 'US',
# and extract only those with 'ShelveLoc' variable level is "Good".
%>%
con_sqlite tbl("TB_CARSEATS") %>%
group_by(ShelveLoc, US) %>%
normality() %>%
filter(ShelveLoc == "Good")
# A tibble: 16 x 6
variable ShelveLoc US statistic p_value sample<chr> <chr> <chr> <dbl> <dbl> <dbl>
1 Sales Good No 0.955 0.342 24
2 Sales Good Yes 0.983 0.567 61
3 CompPrice Good No 0.970 0.658 24
4 CompPrice Good Yes 0.984 0.598 61
# … with 12 more rows
# extract only those with 'Urban' variable level is "Yes",
# and test 'Sales' by 'ShelveLoc' and 'US'
%>%
con_sqlite tbl("TB_CARSEATS") %>%
filter(Urban == "Yes") %>%
group_by(ShelveLoc, US) %>%
normality(Sales)
# A tibble: 6 x 6
variable ShelveLoc US statistic p_value sample<chr> <chr> <chr> <dbl> <dbl> <dbl>
1 Sales Bad No 0.985 0.968 23
2 Sales Bad Yes 0.985 0.774 50
3 Sales Good No 0.959 0.576 18
4 Sales Good Yes 0.969 0.384 37
# … with 2 more rows
# Test log(Income) variables by 'ShelveLoc' and 'US',
# and extract only p.value greater than 0.01.
# SQLite extension functions for log transformation
::initExtension(con_sqlite)
RSQLite
%>%
con_sqlite tbl("TB_CARSEATS") %>%
mutate(log_income = log(Income)) %>%
group_by(ShelveLoc, US) %>%
normality(log_income) %>%
filter(p_value > 0.01)
# A tibble: 1 x 6
variable ShelveLoc US statistic p_value sample<chr> <chr> <chr> <dbl> <dbl> <dbl>
1 log_income Bad No 0.946 0.104 34
```

```
# extract only those with 'ShelveLoc' variable level is "Good",
# and plot 'Income' by 'US'
# the result is same as a data.frame, but not display here. reference above in document.
%>%
con_sqlite tbl("TB_CARSEATS") %>%
filter(ShelveLoc == "Good") %>%
group_by(US) %>%
plot_normality(Income)
```

```
# Correlation coefficient
# that eliminates redundant combination of variables
%>%
con_sqlite tbl("TB_CARSEATS") %>%
correlate() %>%
filter(as.integer(var1) > as.integer(var2))
# A tibble: 28 x 3
var1 var2 coef_corr<fct> <fct> <dbl>
1 CompPrice Sales 0.0641
2 Income Sales 0.141
3 Advertising Sales 0.270
4 Population Sales 0.0505
# … with 24 more rows
%>%
con_sqlite tbl("TB_CARSEATS") %>%
correlate(Sales, Price) %>%
filter(as.integer(var1) > as.integer(var2))
# A tibble: 5 x 3
var1 var2 coef_corr<fct> <fct> <dbl>
1 Price Sales -0.445
2 Price CompPrice 0.585
3 Price Income -0.0484
4 Price Advertising 0.0445
# … with 1 more row
# Compute the correlation coefficient of Sales variable by 'ShelveLoc'
# and 'US' variables. And extract only those with absolute
# value of correlation coefficient is greater than 0.5
%>%
con_sqlite tbl("TB_CARSEATS") %>%
group_by(ShelveLoc, US) %>%
correlate(Sales) %>%
filter(abs(coef_corr) >= 0.5)
# A tibble: 6 x 5
ShelveLoc US var1 var2 coef_corr<chr> <chr> <fct> <fct> <dbl>
1 Bad No Sales Price -0.527
2 Bad Yes Sales Price -0.583
3 Good No Sales Price -0.811
4 Good Yes Sales Price -0.603
# … with 2 more rows
# extract only those with 'ShelveLoc' variable level is "Good",
# and compute the correlation coefficient of 'Sales' variable
# by 'Urban' and 'US' variables.
# And the correlation coefficient is negative and smaller than 0.5
%>%
con_sqlite tbl("TB_CARSEATS") %>%
filter(ShelveLoc == "Good") %>%
group_by(Urban, US) %>%
correlate(Sales) %>%
filter(coef_corr < 0) %>%
filter(abs(coef_corr) > 0.5)
# A tibble: 10 x 5
Urban US var1 var2 coef_corr<chr> <chr> <fct> <fct> <dbl>
1 No No Sales Population -0.530
2 No No Sales Price -0.838
3 No Yes Sales Price -0.644
4 Yes No Sales Price -0.833
# … with 6 more rows
```

```
# Extract only those with 'ShelveLoc' variable level is "Good",
# and visualize correlation plot of 'Sales' variable by 'Urban'
# and 'US' variables.
# the result is same as a data.frame, but not display here. reference above in document.
%>%
con_sqlite tbl("TB_CARSEATS") %>%
filter(ShelveLoc == "Good") %>%
group_by(Urban) %>%
plot_correlate(Sales)
```

The following is an EDA where the target column is character and the predictor column is a numeric type.

```
# If the target variable is a categorical variable
<- target_by(con_sqlite %>% tbl("TB_CARSEATS") , US)
categ
# If the variable of interest is a numerical variable
<- relate(categ, Sales)
cat_num
cat_num# A tibble: 3 x 27
variable US n na mean sd se_mean IQR skewness kurtosis p00<chr> <fct> <int> <int> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Sales No 142 0 6.82 2.60 0.218 3.44 0.323 0.808 0
2 Sales Yes 258 0 7.87 2.88 0.179 4.23 0.0760 -0.326 0.37
3 Sales total 400 0 7.50 2.82 0.141 3.93 0.186 -0.0809 0
# … with 16 more variables: p01 <dbl>, p05 <dbl>, p10 <dbl>, p20 <dbl>,
# p25 <dbl>, p30 <dbl>, p40 <dbl>, p50 <dbl>, p60 <dbl>, p70 <dbl>,
# p75 <dbl>, p80 <dbl>, p90 <dbl>, p95 <dbl>, p99 <dbl>, p100 <dbl>
summary(cat_num)
variable US n na mean :3 No :1 Min. :142.0 Min. :0 Min. :6.823
Length:character Yes :1 1st Qu.:200.0 1st Qu.:0 1st Qu.:7.160
Class :character total:1 Median :258.0 Median :0 Median :7.496
Mode :266.7 Mean :0 Mean :7.395
Mean :329.0 3rd Qu.:0 3rd Qu.:7.682
3rd Qu.:400.0 Max. :0 Max. :7.867
Max.
sd se_mean IQR skewness :2.603 Min. :0.1412 Min. :3.442 Min. :0.07603
Min. :2.713 1st Qu.:0.1602 1st Qu.:3.686 1st Qu.:0.13080
1st Qu.:2.824 Median :0.1791 Median :3.930 Median :0.18556
Median :2.768 Mean :0.1796 Mean :3.866 Mean :0.19489
Mean :2.851 3rd Qu.:0.1988 3rd Qu.:4.077 3rd Qu.:0.25432
3rd Qu.:2.877 Max. :0.2184 Max. :4.225 Max. :0.32308
Max.
kurtosis p00 p01 p05 :-0.32638 Min. :0.0000 Min. :0.4675 Min. :3.147
Min. :-0.20363 1st Qu.:0.0000 1st Qu.:0.6868 1st Qu.:3.148
1st Qu.:-0.08088 Median :0.0000 Median :0.9062 Median :3.149
Median : 0.13350 Mean :0.1233 Mean :1.0072 Mean :3.183
Mean : 0.36344 3rd Qu.:0.1850 3rd Qu.:1.2771 3rd Qu.:3.200
3rd Qu.: 0.80776 Max. :0.3700 Max. :1.6480 Max. :3.252
Max.
p10 p20 p25 p30 :3.917 Min. :4.754 Min. :5.080 Min. :5.306
Min. :4.018 1st Qu.:4.910 1st Qu.:5.235 1st Qu.:5.587
1st Qu.:4.119 Median :5.066 Median :5.390 Median :5.867
Median :4.073 Mean :5.051 Mean :5.411 Mean :5.775
Mean :4.152 3rd Qu.:5.199 3rd Qu.:5.576 3rd Qu.:6.010
3rd Qu.:4.184 Max. :5.332 Max. :5.763 Max. :6.153
Max.
p40 p50 p60 p70 :5.994 Min. :6.660 Min. :7.496 Min. :7.957
Min. :6.301 1st Qu.:7.075 1st Qu.:7.787 1st Qu.:8.386
1st Qu.:6.608 Median :7.490 Median :8.078 Median :8.815
Median :6.506 Mean :7.313 Mean :8.076 Mean :8.740
Mean :6.762 3rd Qu.:7.640 3rd Qu.:8.366 3rd Qu.:9.132
3rd Qu.:6.916 Max. :7.790 Max. :8.654 Max. :9.449
Max.
p75 p80 p90 p95 :8.523 Min. : 8.772 Min. : 9.349 Min. :11.28
Min. :8.921 1st Qu.: 9.265 1st Qu.:10.325 1st Qu.:11.86
1st Qu.:9.320 Median : 9.758 Median :11.300 Median :12.44
Median :9.277 Mean : 9.665 Mean :10.795 Mean :12.08
Mean :9.654 3rd Qu.:10.111 3rd Qu.:11.518 3rd Qu.:12.49
3rd Qu.:9.988 Max. :10.464 Max. :11.736 Max. :12.54
Max.
p99 p100 :13.64 Min. :14.90
Min. :13.78 1st Qu.:15.59
1st Qu.:13.91 Median :16.27
Median :13.86 Mean :15.81
Mean :13.97 3rd Qu.:16.27
3rd Qu.:14.03 Max. :16.27 Max.
```

```
# the result is same as a data.frame, but not display here. reference above in document.
plot(cat_num)
```

The following shows several examples of creating an EDA report for a DBMS table.

Using the `collect_size`

argument, you can perform EDA with the corresponding number of sample data. If the number of data is very large, use `collect_size`

.

```
# create web report file.
%>%
con_sqlite tbl("TB_CARSEATS") %>%
eda_web_report()
# create pdf file. file name is EDA.pdf, and collect size is 350
%>%
con_sqlite tbl("TB_CARSEATS") %>%
eda_paged_report(collect_size = 350, output_file = "EDA.pdf")
```