This tutorial is all about exploratory data analysis
Most of the data we will look at is in “data.frame” format. This is a table, just like an excel spreadsheet, with one row for each observation and one column for each variable. Each column has a column name.
In this tutorial, I will focus on in-built R datasets.
Let’s choose one now. I’m going to work with the pirates dataset from the yarrr package. We can choose the data here.
library(yarrr)
library(tidyverse)
?pirates
piratedataset <- piratesTo have a look at the data there are many options. You can:
piratedataset into the console or a code chunk)View(variable_name) (View is a command from the tidyverse package).head(variable_name) to see the first 6 lines or so (good for quick checks)glimpse(variable_name) to get a nice summary.names(variable_name) to get the column names.For example
# Note, there are more columns to the right, use the arrow to see
head(piratedataset)## id sex age height weight headband college tattoos tchests parrots
## 1 1 male 28 173.11 70.5 yes JSSFP 9 0 0
## 2 2 male 31 209.25 105.6 yes JSSFP 9 11 0
## 3 3 male 26 169.95 77.1 yes CCCC 10 10 1
## 4 4 female 31 144.29 58.5 no JSSFP 2 0 2
## 5 5 female 41 157.85 58.4 yes JSSFP 9 6 4
## 6 6 male 26 190.20 85.4 yes CCCC 7 19 0
## favorite.pirate sword.type eyepatch sword.time beard.length
## 1 Jack Sparrow cutlass 1 0.58 16
## 2 Jack Sparrow cutlass 0 1.11 21
## 3 Jack Sparrow cutlass 1 1.44 19
## 4 Jack Sparrow scimitar 1 36.11 2
## 5 Hook cutlass 1 0.11 0
## 6 Jack Sparrow cutlass 1 0.59 17
## fav.pixar grogg
## 1 Monsters, Inc. 11
## 2 WALL-E 9
## 3 Inside Out 7
## 4 Inside Out 9
## 5 Inside Out 14
## 6 Monsters University 7To see what the column names are, you can use the names(dataset) command
names(piratedataset)## [1] "id" "sex" "age" "height"
## [5] "weight" "headband" "college" "tattoos"
## [9] "tchests" "parrots" "favorite.pirate" "sword.type"
## [13] "eyepatch" "sword.time" "beard.length" "fav.pixar"
## [17] "grogg"Or the glimpse command:
glimpse(piratedataset)## Rows: 1,000
## Columns: 17
## $ id <int> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,…
## $ sex <chr> "male", "male", "male", "female", "female", "male", "f…
## $ age <dbl> 28, 31, 26, 31, 41, 26, 31, 31, 28, 30, 25, 20, 24, 26…
## $ height <dbl> 173.11, 209.25, 169.95, 144.29, 157.85, 190.20, 158.05…
## $ weight <dbl> 70.5, 105.6, 77.1, 58.5, 58.4, 85.4, 59.6, 74.5, 68.7,…
## $ headband <chr> "yes", "yes", "yes", "no", "yes", "yes", "yes", "yes",…
## $ college <chr> "JSSFP", "JSSFP", "CCCC", "JSSFP", "JSSFP", "CCCC", "J…
## $ tattoos <dbl> 9, 9, 10, 2, 9, 7, 9, 5, 12, 12, 10, 14, 8, 9, 14, 8, …
## $ tchests <dbl> 0, 11, 10, 0, 6, 19, 1, 13, 37, 69, 1, 5, 6, 12, 70, 3…
## $ parrots <dbl> 0, 0, 1, 2, 4, 0, 7, 7, 2, 4, 3, 3, 0, 3, 0, 1, 0, 3, …
## $ favorite.pirate <chr> "Jack Sparrow", "Jack Sparrow", "Jack Sparrow", "Jack …
## $ sword.type <chr> "cutlass", "cutlass", "cutlass", "scimitar", "cutlass"…
## $ eyepatch <dbl> 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, …
## $ sword.time <dbl> 0.58, 1.11, 1.44, 36.11, 0.11, 0.59, 3.01, 0.06, 0.74,…
## $ beard.length <dbl> 16, 21, 19, 2, 0, 17, 1, 1, 1, 25, 1, 27, 0, 19, 0, 1,…
## $ fav.pixar <chr> "Monsters, Inc.", "WALL-E", "Inside Out", "Inside Out"…
## $ grogg <dbl> 11, 9, 7, 9, 14, 7, 9, 12, 16, 9, 7, 8, 12, 7, 9, 10, …To see how many columns and rows there are, you can use the nrow() and ncol() commands
nrow(piratedataset)## [1] 1000ncol(piratedataset)## [1] 17To look at the summaries there are a load of options. Choose your favourites:
summary(dataset)skim(dataset) in the skimr packagesummarize(dataset) in the papeR package. This looks pretty powerful, I’m just learning itOr look at the summary
summary(piratedataset) ## id sex age height
## Min. : 1.0 Length:1000 Min. :11.00 Min. :129.8
## 1st Qu.: 250.8 Class :character 1st Qu.:24.00 1st Qu.:161.4
## Median : 500.5 Mode :character Median :27.00 Median :169.9
## Mean : 500.5 Mean :27.36 Mean :170.2
## 3rd Qu.: 750.2 3rd Qu.:31.00 3rd Qu.:178.5
## Max. :1000.0 Max. :46.00 Max. :209.2
## weight headband college tattoos
## Min. : 33.00 Length:1000 Length:1000 Min. : 0.000
## 1st Qu.: 62.08 Class :character Class :character 1st Qu.: 7.000
## Median : 69.55 Mode :character Mode :character Median :10.000
## Mean : 69.74 Mean : 9.429
## 3rd Qu.: 76.90 3rd Qu.:12.000
## Max. :105.60 Max. :19.000
## tchests parrots favorite.pirate sword.type
## Min. : 0.00 Min. : 0.000 Length:1000 Length:1000
## 1st Qu.: 6.00 1st Qu.: 1.000 Class :character Class :character
## Median : 15.00 Median : 2.000 Mode :character Mode :character
## Mean : 22.69 Mean : 2.819
## 3rd Qu.: 30.00 3rd Qu.: 4.000
## Max. :147.00 Max. :27.000
## eyepatch sword.time beard.length fav.pixar
## Min. :0.000 Min. : 0.0000 Min. : 0.00 Length:1000
## 1st Qu.:0.000 1st Qu.: 0.2175 1st Qu.: 0.00 Class :character
## Median :1.000 Median : 0.5850 Median : 9.00 Mode :character
## Mean :0.658 Mean : 2.5427 Mean :10.38
## 3rd Qu.:1.000 3rd Qu.: 1.3300 3rd Qu.:20.00
## Max. :1.000 Max. :169.8800 Max. :40.00
## grogg
## Min. : 0.00
## 1st Qu.: 8.00
## Median :10.00
## Mean :10.14
## 3rd Qu.:12.00
## Max. :21.00In the skimr library there is the skim command
library(skimr)
skim(piratedataset) | Name | piratedataset |
| Number of rows | 1000 |
| Number of columns | 17 |
| _______________________ | |
| Column type frequency: | |
| character | 6 |
| numeric | 11 |
| ________________________ | |
| Group variables | None |
Variable type: character
| skim_variable | n_missing | complete_rate | min | max | empty | n_unique | whitespace |
|---|---|---|---|---|---|---|---|
| sex | 0 | 1 | 4 | 6 | 0 | 3 | 0 |
| headband | 0 | 1 | 2 | 3 | 0 | 2 | 0 |
| college | 0 | 1 | 4 | 5 | 0 | 2 | 0 |
| favorite.pirate | 0 | 1 | 4 | 12 | 0 | 6 | 0 |
| sword.type | 0 | 1 | 5 | 8 | 0 | 4 | 0 |
| fav.pixar | 0 | 1 | 2 | 19 | 0 | 15 | 0 |
Variable type: numeric
| skim_variable | n_missing | complete_rate | mean | sd | p0 | p25 | p50 | p75 | p100 | hist |
|---|---|---|---|---|---|---|---|---|---|---|
| id | 0 | 1 | 500.50 | 288.82 | 1.00 | 250.75 | 500.50 | 750.25 | 1000.00 | ▇▇▇▇▇ |
| age | 0 | 1 | 27.36 | 5.79 | 11.00 | 24.00 | 27.00 | 31.00 | 46.00 | ▁▅▇▃▁ |
| height | 0 | 1 | 170.23 | 12.39 | 129.83 | 161.36 | 169.86 | 178.54 | 209.25 | ▁▅▇▅▁ |
| weight | 0 | 1 | 69.74 | 10.82 | 33.00 | 62.08 | 69.55 | 76.90 | 105.60 | ▁▃▇▅▁ |
| tattoos | 0 | 1 | 9.43 | 3.37 | 0.00 | 7.00 | 10.00 | 12.00 | 19.00 | ▁▃▇▃▁ |
| tchests | 0 | 1 | 22.69 | 24.46 | 0.00 | 6.00 | 15.00 | 30.00 | 147.00 | ▇▂▁▁▁ |
| parrots | 0 | 1 | 2.82 | 3.21 | 0.00 | 1.00 | 2.00 | 4.00 | 27.00 | ▇▁▁▁▁ |
| eyepatch | 0 | 1 | 0.66 | 0.47 | 0.00 | 0.00 | 1.00 | 1.00 | 1.00 | ▅▁▁▁▇ |
| sword.time | 0 | 1 | 2.54 | 9.33 | 0.00 | 0.22 | 0.58 | 1.33 | 169.88 | ▇▁▁▁▁ |
| beard.length | 0 | 1 | 10.38 | 10.31 | 0.00 | 0.00 | 9.00 | 20.00 | 40.00 | ▇▂▅▂▁ |
| grogg | 0 | 1 | 10.14 | 3.07 | 0.00 | 8.00 | 10.00 | 12.00 | 21.00 | ▁▅▇▃▁ |
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