class: center, middle, inverse, title-slide

.title[
# Tidy data
]
.subtitle[
## <br><br> Data Science in a Box
]
.author[
### <a href="https://datasciencebox.org/">datasciencebox.org</a>
]

---

layout: true
  
<div class="my-footer">
<span>
<a href="https://datasciencebox.org" target="_blank">datasciencebox.org</a>
</span>
</div>

---

## Tidy data

>Happy families are all alike; every unhappy family is unhappy in its own way. 
>
>Leo Tolstoy

--

.pull-left[
**Characteristics of tidy data:**

- Each variable forms a column.
- Each observation forms a row.
- Each type of observational unit forms a table.
]
--
.pull-right[
**Characteristics of untidy data:**

!@#$%^&*()
]

---

##

.question[
What makes this data not tidy?
]

<img src="img/hyperwar-airplanes-on-hand.png" width="70%" style="display: block; margin: auto;" />

.footnote[
Source: [Army Air Forces Statistical Digest, WW II](https://www.ibiblio.org/hyperwar/AAF/StatDigest/aafsd-3.html)
]

---

.question[
What makes this data not tidy?
]

<br>

<img src="img/hiv-est-prevalence-15-49.png" width="70%" style="display: block; margin: auto;" />

.footnote[
Source: [Gapminder, Estimated HIV prevalence among 15-49 year olds](https://www.gapminder.org/data)
]

---

.question[
What makes this data not tidy?
]

<br>

<img src="img/us-general-economic-characteristic-acs-2017.png" width="85%" style="display: block; margin: auto;" />

.footnote[
Source: [US Census Fact Finder, General Economic Characteristics, ACS 2017](https://factfinder.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=ACS_17_5YR_DP03&src=pt)
]

---

## Displaying vs. summarising data

.panelset[

.panel[.panel-name[Output]

.pull-left[

```
## # A tibble: 87 × 3
##   name           height  mass
##   <chr>           <int> <dbl>
## 1 Luke Skywalker    172    77
## 2 C-3PO             167    75
## 3 R2-D2              96    32
## 4 Darth Vader       202   136
## 5 Leia Organa       150    49
## 6 Owen Lars         178   120
## # … with 81 more rows
```
]
.pull-right[

```
## # A tibble: 3 × 2
##   gender    avg_ht
##   <chr>      <dbl>
## 1 feminine    165.
## 2 masculine   177.
## 3 <NA>        181.
```
]

]

.panel[.panel-name[Code]

.pull-left[

```r
starwars %>%
  select(name, height, mass)
```
]
.pull-right[

```r
starwars %>%
  group_by(gender) %>%
  summarize(
    avg_ht = mean(height, na.rm = TRUE)
    )
```
]

]

]

Notes for current slide

Notes for next slide

Tidy data

Data Science in a Box

datasciencebox.org

1 / 6

Tidy data

Happy families are all alike; every unhappy family is unhappy in its own way.

Leo Tolstoy

2 / 6

Tidy data

Happy families are all alike; every unhappy family is unhappy in its own way.

Leo Tolstoy

Characteristics of tidy data:

Each variable forms a column.
Each observation forms a row.
Each type of observational unit forms a table.

2 / 6

Tidy data

Happy families are all alike; every unhappy family is unhappy in its own way.

Leo Tolstoy

Characteristics of tidy data:

Each variable forms a column.
Each observation forms a row.
Each type of observational unit forms a table.

Characteristics of untidy data:

!@#$%^&*()

2 / 6

What makes this data not tidy?

Source: Army Air Forces Statistical Digest, WW II

3 / 6

What makes this data not tidy?

Source: Gapminder, Estimated HIV prevalence among 15-49 year olds

4 / 6

What makes this data not tidy?

Source: US Census Fact Finder, General Economic Characteristics, ACS 2017

5 / 6

Displaying vs. summarising data

## # A tibble: 87 × 3
##   name           height  mass
##   <chr>           <int> <dbl>
## 1 Luke Skywalker    172    77
## 2 C-3PO             167    75
## 3 R2-D2              96    32
## 4 Darth Vader       202   136
## 5 Leia Organa       150    49
## 6 Owen Lars         178   120
## # … with 81 more rows

## # A tibble: 3 × 2
##   gender    avg_ht
##   <chr>      <dbl>
## 1 feminine    165.
## 2 masculine   177.
## 3 <NA>        181.

starwars %>%
  select(name, height, mass)

starwars %>%
  group_by(gender) %>%
  summarize(
    avg_ht = mean(height, na.rm = TRUE)
    )

6 / 6

Tidy data

Happy families are all alike; every unhappy family is unhappy in its own way.

Leo Tolstoy

2 / 6

Paused

Help

Keyboard shortcuts

↑, ←, Pg Up, k	Go to previous slide
↓, →, Pg Dn, Space, j	Go to next slide
Home	Go to first slide
End	Go to last slide
Number + Return	Go to specific slide
b / m / f	Toggle blackout / mirrored / fullscreen mode
c	Clone slideshow
p	Toggle presenter mode
t	Restart the presentation timer
?, h	Toggle this help

Esc	Back to slideshow