ggplot basics II

# ggplot basics II
### Intro to data visualization with ggplot2 <a href='https://therbootcamp.github.io'> The R Bootcamp </a> <a href='https://therbootcamp.github.io/SDGDataViz_2021Nov/'> </a>  <a href='https://therbootcamp.github.io'> </a>  <a href='therbootcamp@gmail.com'> </a>  <a href='https://www.linkedin.com/company/27090302'> </a>
### November 2021

---

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 Intro to data visualization with ggplot2 | Novemeber 2021
 
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---

# Simple styling

<ul>
 <li class="m1">Save plot as <highm>gg</highm> object.</li>
 <li class="m2">Use existing <highm>theme_*()</highm> presets.</li>
 <li class="m3">Customize details using <highm>theme()</highm>.</li>
 <li class="m4">Adjust dimensions using <highm>scale_*()</highm>.</li>
 <li class="m5">Add annotion using <highm>labs()</highm>.</li>
 <li class="m6">Write your plot as a <highm>.png</highm> or <highm>.png</highm>.</li>
</ul>

]

<img src="PlottingII_files/figure-html/unnamed-chunk-2-1.png" style="display: block; margin: auto;" />
]

---

# the <mono>gg</mono> object

<ul>
 <li class="m1">The output of <mono>ggplot()</mono> can be stored in an <mono>gg</mono> object.</li>
 <li class="m2">The <mono>gg</mono> object can be expanded using <mono>+</mono> and the plot can be generated by a simple print.</li>
</ul>

```r
# store plot as object
my_plot <- sdg_props %>% 
 ggplot(aes(x = year, y = prop, col = sdg)) +
 geom_point() + 
 geom_line()
```

]

```r
my_plot 
```

]

---

# `theme_*()`

<ul>
 <li class="m1">Using <mono>theme_*()</mono> the plot can be styled according to various presets.</li>
 <li class="m2">A few <mono>theme</mono>s:
 
 <ul class="level">
 <li><mono>theme_gray()</mono></li>
 <li><mono>theme_classic()</mono></li>
 <li><mono>theme_void()</mono></li>
 <li><mono>theme_minimal()</mono></li>
 <li><mono>theme_excel() (<mono>ggthemes</mono>)</mono></li>
 <li><mono>theme_economist() (<mono>ggthemes</mono>)</mono></li>
 </ul>
 </li>
</ul>

]

```r
my_plot + theme_classic()
```

]

---

# `theme_*()`

]

```r
my_plot + theme_excel()
```

]

---

# `theme_*()`

]

```r
my_plot + theme_economist()
```

]

---

# `theme_*()`

]

```r
my_plot + theme_wsj()
```

]

---

# `theme_*()`

]

```r
my_plot + theme_minimal()
```

]

---

# `theme()`

<ul>
 <li class="m1">With <high>87 arguments</high> <mono>theme()</mono> permits specification of all aesthetic details.</li>
 <li class="m2">Makes uses of helper functions:</li>
 <ul class="level">
 <li><mono>element_rect()</mono> | for rectangles</li>
 <li><mono>element_line()</mono> | for lines</li>
 <li><mono>element_text()</mono> | for text</li>
 <li><mono>element_blank()</mono> | for removals</li>
 </ul>
</ul>

```r
# Using theme
my_plot + 
  theme(argument = element_*(), 
        argument = element_*(),
        ...)
```

]

<img src="image/theme.png">

]

---

# `theme()`

```r
# Fixing the legend
my_plot + 
  theme_minimal() +
  
  # move legend to top
  theme(legend.position = "top")
```

]

]

---

# `theme()`

```r
# Fixing the legend
my_plot + 
  theme_minimal() +
  
  # move legend to top
  theme(legend.position = c(.85, .5))
```

]

]

---

# `theme()`

```r
# Fixing the legend
my_plot + 
  theme_minimal() +
  theme(legend.position = c(.85, .5),
        
        # remove legend title
        legend.title = element_blank())
```

]

]

---

# `theme()`

```r
# Fixing the legend
my_plot + 
  theme_minimal() +
  theme(
    legend.position = c(.85, .5),
    legend.title = element_blank(),
    
    # increase legend text size
    legend.text = element_text(size = 10))
```

]

]

---

# `theme()`

```r
# Fixing the legend
my_plot + 
  theme_minimal() +
  theme(
    legend.position = c(.85, .5),
    legend.title = element_blank(),
    legend.text = element_text(size = 10),
    
    # add white background
    legend.background = 
      element_rect(fill = "white"))
```

]

]

---

# `theme()`

]

]

---

# `scale_*()`

<ul>
 <li class="m1">Various <mono>scale_*()</mono> permit specification of all <high>dimensions</high>, inclding axes, colors, sizes, etc.</li>
 <li class="m2">Groups of <mono>scale_*()</mono> functions:</li>
 <ul class="level">
 <li><mono>scale_xy_*</mono> | Scales axes</li>
 <li><mono>scale_color_*</mono> | Scales colors</li>
 <li><mono>scale_size_*</mono> | Sclaes sizes</li>
 <li><mono>scale_alpha_*</mono> | Scales opacity</li>
 </ul>
</ul>

]

]

---

# `scale_*()`

<ul>
 <li class="m1">Various <mono>scale_*()</mono> permit specification of all <high>dimensions</high>, inclding axes, colors, sizes, etc.</li>
</ul>

```r
# Changing colors
my_plot + 
  theme_minimal() +
  theme(
    legend.position = c(.85, .5),
    legend.title = element_blank(),
    legend.text = element_text(size = 10),
    legend.background = 
      element_rect(fill = "white",
                   color = "white")) + 
  
  # color using own values
  scale_color_manual(values = c("#A5D7D2", 
                                "#2D373C"))
```

]

]

---

# `scale_*()`

<ul>
 <li class="m1">Various <mono>scale_*()</mono> permit specification of all <high>dimensions</high>, inclding axes, colors, sizes, etc.</li>
</ul>

]

]

---

# `scale_*()`

<ul>
 <li class="m1">Various <mono>scale_*()</mono> permit specification of all <high>dimensions</high>, inclding axes, colors, sizes, etc.</li>
</ul>

```r
# Changing colors
my_plot + 
  theme_minimal() +
  theme(
    legend.position = c(.85, .5),
    legend.title = element_blank(),
    legend.text = element_text(size = 10),
    legend.background = 
      element_rect(fill = "white",
                   color = "white")) + 
  
  # color using colorblind
  scale_color_colorblind(
    labels = c("No poverty (SDG 1)", 
               "Clean water (SDG 6)"))
```

]

]

---

# `geom` constants

<ul>
 <li class="m1">Most aesthetics can be set to constants within the <mono>geom_*()</mono> outside of <mono>aes()</mono></li>
</ul>

```r
# store plot as object
my_plot <- sdg_props %>% 
 ggplot(aes(x = year, y = prop, col = sdg)) +
 geom_point(size = 4) + 
 geom_line()
```

]

```r
my_plot 
```

]

---

# `scale_*()`

<ul>
 <li class="m1">Various <mono>scale_*()</mono> permit specification of all <high>dimensions</high>, inclding axes, colors, sizes, etc.</li>
</ul>

```r
# Constants have changed
my_plot + 
  theme_minimal() +
  theme(
    legend.position = c(.85, .5),
    legend.title = element_blank(),
    legend.text = element_text(size = 10),
    legend.background = 
      element_rect(fill = "white",
                   color = "white")) + 
  
  # color using colorblind
  scale_color_colorblind(
    labels = c("No poverty (SDG 1)", 
               "Clean water (SDG 6)"))
```

]

]

---

# `labs()`

<ul>
 <li class="m1">Vaious annotions can be added using <mono>labs()</mono>.</li>
 <li class="m2">Key arguments:</li>
 <ul class="level">
 <li><mono>x,y</mono> | Axes</li>
 <li><mono>title, subtitle</mono> | Title and Subtitle</high></li>
 <li><mono>caption</mono> | Caption</high></li>
 </ul>
</ul>

```r
my_plot +
  labs(x = "Year of project start",
       y = "Relative proportion",
       title = "SDGs in Swiss Research...",
       subtitle = "Relative proportion of...")
```

]

]

---

# `ggsave()`

<ul>
 <li class="m1">Saves plots to the harddrive.</li>
 <li class="m2">Key arguments:</li>
 <ul class="level">
 <li><mono>filename</mono> | Filename/path</li>
 <li><mono>device</mono> | e.g., <mono>".pdf"</mono> or <mono>".png"</mono></li>
 <li><mono>path</mono> | Path to folder</li>
 <li><mono>height, width</mono> | Height, Width</li>
 <li><mono>unit</mono> | Unit for Height, Width</li>
 <li><mono>dpi</mono> | Resolution</li>
 </ul>
</ul>

]

```r
# Save as pdf
ggsave(filename = "my_plot.pdf",
       plot = my_plot,
       device = "pdf",
       path = "3_Figures",
       width = 7, 
       height = 7)

# Save as png
ggsave(filename = "my_plot.png",
       plot = my_plot,
       device = "png",
       path = "3_Figures",
       width = 7, 
       height = 7,
       dpi = 300)
```

]

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