viz.knit

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# .white.big-text[Data Visualisation]
## .white[Session - 3]

---

# Course Progress

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# .big-text[Data]

---

# Variable types in R:

- `int` stands for integers, like 4, 55, 300.

- `dbl` stands for doubles, or real numbers like 3, 7.45, 1.565, 12.

- `chr` stands for character vectors, or strings like names.

- `dttm` stands for date-times (a date + a time).

- `lgl` stands for logical, vectors that contain only TRUE or FALSE.

- `fct` stands for factors, which R uses to represent **categorical variables** with fixed possible values like occupation: student, professional, government, business.

- `date` stands for dates.

---

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# Data of Palmer Penguins

- It comes with R package `palmerpenguins`

- Name of the data is `penguins`

- To know more about the data `?penguins`

- Included variables are:
  - species, island, bill_length_mm, bill_depth_mm, flipper_length_mm, body_mass_g, sex, year

---

# An Overview of Data

```r
*glimpse(penguins)
```

]

```
## Rows: 344
## Columns: 8
## $ species           <fct> Adelie, Adelie, Adelie, Adelie, Adelie, Adelie, Adel…
## $ island            <fct> Torgersen, Torgersen, Torgersen, Torgersen, Torgerse…
## $ bill_length_mm    <dbl> 39.1, 39.5, 40.3, NA, 36.7, 39.3, 38.9, 39.2, 34.1, …
## $ bill_depth_mm     <dbl> 18.7, 17.4, 18.0, NA, 19.3, 20.6, 17.8, 19.6, 18.1, …
## $ flipper_length_mm <int> 181, 186, 195, NA, 193, 190, 181, 195, 193, 190, 186…
## $ body_mass_g       <int> 3750, 3800, 3250, NA, 3450, 3650, 3625, 4675, 3475, …
## $ sex               <fct> male, female, female, NA, female, male, female, male…
## $ year              <int> 2007, 2007, 2007, 2007, 2007, 2007, 2007, 2007, 2007…
```

]
]

---

### An Overview of Data

```r
*summary(penguins)
```

]

```
##       species          island    bill_length_mm  bill_depth_mm  
##  Adelie   :152   Biscoe   :168   Min.   :32.10   Min.   :13.10  
##  Chinstrap: 68   Dream    :124   1st Qu.:39.23   1st Qu.:15.60  
##  Gentoo   :124   Torgersen: 52   Median :44.45   Median :17.30  
##                                  Mean   :43.92   Mean   :17.15  
##                                  3rd Qu.:48.50   3rd Qu.:18.70  
##                                  Max.   :59.60   Max.   :21.50  
##                                  NA's   :2       NA's   :2      
##  flipper_length_mm  body_mass_g       sex           year     
##  Min.   :172.0     Min.   :2700   female:165   Min.   :2007  
##  1st Qu.:190.0     1st Qu.:3550   male  :168   1st Qu.:2007  
##  Median :197.0     Median :4050   NA's  : 11   Median :2008  
##  Mean   :200.9     Mean   :4202                Mean   :2008  
##  3rd Qu.:213.0     3rd Qu.:4750                3rd Qu.:2009  
##  Max.   :231.0     Max.   :6300                Max.   :2009  
##  NA's   :2         NA's   :2
```

]
]

---

# Packages required:

```r
library(palmerpenguins) # to access penguin data
library(tidyverse) # to use ggplot2 pkg
```

- Packages recommended:

```r
install.packages(c(
  "directlabels", "dplyr", "gameofthrones", "ggforce", "gghighlight", 
  "ggnewscale", "ggplot2", "ggraph", "ggrepel", "ggtext", "ggthemes", 
  "hexbin", "mapproj", "maps", "munsell", "ozmaps", "paletteer", 
  "patchwork", "rmapshaper", "scico", "seriation", "sf", "stars", 
  "tidygraph", "tidyr", "wesanderson" 
))
```

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background-image: url("images/ggplot-logo.png")
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# .big-text[R<br>Package]

---

# ggplot2 by [Hadley Wickham](http://hadley.nz/)
<br>
- "is a system for declaratively creating graphics, based on [The Grammar of Graphics](https://www.springer.com/gp/book/9780387245447)" (book by Late Leland Wilkinson)

.pull-left[
<div class="figure" style="text-align: center">
<img src="https://upload.wikimedia.org/wikipedia/en/b/b5/Leland_Wilkinson.png" alt="Late Leland Wilkinson" width="40%" />
<p class="caption">Late Leland Wilkinson</p>
</div>
]

.pull-right[
<div class="figure" style="text-align: center">
<img src="images/hadley.jpg" alt="Hadley Wickham" width="58%" />
<p class="caption">Hadley Wickham</p>
</div>
]

---
class: hide-count, hide-logo

background-image: url("images/layer7.png")
background-size: contain
background-position: 50% 50%

---

# Key Components for ggplot2 Plot

1. data,

1. aesthetic mapping

1. at least one layer of geom function

---

]

```r
*ggplot(data = penguins)
```

]

]
]

---

]

```r
*ggplot(data = penguins, mapping = aes(x = species))
```

]

]
]

---

]

```r
ggplot(data = penguins, mapping = aes(x = species)) +
* geom_bar()
```

]

]
]

---

```r
ggplot(penguins, aes(x = species)) +
  geom_bar() 
```

]

]
]

---

# 🧠 YOUR TURN

]

```r
ggplot(data = penguins, mapping = aes(x = island)) +
  geom_bar() 
```

]
]

---

# How to export plot to your computer?

---

```r
ggplot(data = penguins, mapping = aes(x = species)) +
  geom_bar()

*ggsave("peng-species.pdf")  # also try jpg/jpeg/png
```

]

```
## Saving 7 x 7 in image
```

]
]

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class: center, middle

# How to add color to bars?

---

```r
ggplot(data = penguins, mapping = aes(x = species)) +
* geom_bar(fill = "blue")
```

]

]
]

---

```r
ggplot(data = penguins, mapping = aes(x = species)) +
* geom_bar(fill = c("orange", "white", "green"))

# color names should be equal to the factor levels
# in case of factor species levels are three
# Adele, Chinstrap & Gentoo
```

]

]
]

---

# How to add color using palette? 🎨

---

## 🎨 Color Palette

- R package `RColorBrewer` & `wesanderson`

---

```r
library(RColorBrewer)

ggplot(data = penguins,
       mapping = aes(x = species,
*                    fill = species)) +
  geom_bar() +
* scale_fill_brewer(palette = "Dark2")

```

]

]
]

---

# How to remove legend or change its position?

---

```r
ggplot(data = penguins,
       mapping = aes(x = species,
                     fill = species)) + 
  geom_bar() +
  scale_fill_brewer(palette = "Dark2") +
  theme(legend.position = "none") # top, bottom, left

```

]

]
]

---

# How to plot title and axis titles?

---

```r
ggplot(data = penguins,
       mapping = aes(x = species,
                     fill = species)) +
  geom_bar() +
  scale_fill_brewer(palette = "Dark2") +
  theme(legend.position = "none") +
  labs(
    title = "Species of palmer penguins",
    subtitle = "This data is about penguins",
    x = "Species",
    y = "Frequency"
  )

```

]

]
]

---

# How to control size of text?

---

```r
ggplot(data = penguins,
       mapping = aes(x = species,
                     fill = species)) +
  geom_bar() +
  scale_fill_brewer(palette = "Dark2") +
  theme(legend.position = "none",
*       text = element_text(size = 20)) +
  labs(
    title = "Species of palmer penguins",
    subtitle = "This data is about penguins",
    x = "Species",
    y = "Frequency"
  )

```

]

]
]

---

# How to plot two numeric variables?

---

```r
ggplot(data = penguins,
       mapping = aes(x = bill_length_mm,
                     y = bill_depth_mm,
                     color = species)) +
  geom_point() +
  scale_fill_brewer(palette = "Dark2") +
  theme(legend.position = "none",
*       text = element_text(size = 20)) +
  labs(
    title = "Relationship between bill length \n& depth of palmer penguins",
    subtitle = "This data is about penguins",
    x = "Bill length (mm)",
    y = "Bith depth (mm)"
  )

```

]

]
]

---

# How to add themes to ggplot?

---

# ggplot2 themes

<https://ggplot2.tidyverse.org/reference/ggtheme.html>

- theme_gray()

- theme_bw()

- theme_linedraw()

- theme_light()

- theme_dark()

- theme_minimal()

- theme_classic()

- theme_void()

- theme_test()

---

```r
ggplot(data = penguins,
       mapping = aes(x = bill_length_mm,
                     y = bill_depth_mm,
                     color = species)) +
  geom_point() +
  scale_fill_brewer(palette = "Dark2") +
  theme(legend.position = "none",
        text = element_text(size = 20)) + 
  labs(
    title = "Relationship between bill length \n& depth of palmer penguins",
    subtitle = "This data is about penguins",
    x = "Bill length (mm)",
    y = "Bith depth (mm)"
  ) +
* theme_bw()

```

]

]
]

---

```

]

]
]

---

# How to add regression line to ggplot?

---

```r
ggplot(data = penguins,
       mapping = aes(x = flipper_length_mm,
                     y = body_mass_g)) +
  geom_point() +
  theme(legend.position = "none",
        text = element_text(size = 24)) + 
  labs(
    title = "Relationship between bill length \n& depth of palmer penguins",
    subtitle = "This data is about penguins",
    x = "Flipper length (mm)",
    y = "Body mass (gm)"
  ) +
  theme_classic() +
* geom_smooth()

```

]

]
]

---

# More resources

- ggplot2 book https://ggplot2-book.org/

- CÉDRIC SCHERER https://www.cedricscherer.com/

- ggplot2 cook book http://www.cookbook-r.com/

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#  🙋🏽‍♀️🙋‍♂️<br>.big-text[Q&A]

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# Dynamic Wrangling<br>Using dplyr
### .orange[Next Module - 4]