14 -Building a Plot Layer by Layer.Rmd

---
title: "ggplot2 Elegant Graphics"
author: "Brandon Foltz"
date: "2023-03-15"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
library(tidyverse)
```

```{r}
p  <- ggplot(mpg, aes(displ, hwy))
p
p + geom_point()
p + layer(
  mapping = NULL, # uses the default from the ggplot()
  data = NULL, # uses the default from the ggplot()
  geom = "point",
  stat = "identity", # keep data as-is
  position = "identity"
)
```
Different data on layers

```{r}
mod <- loess(hwy ~ displ, data = mpg)
grid <- tibble(displ = seq(min(mpg$displ), max(mpg$displ), length = 50))
grid$hwy <- predict(mod, newdata = grid)

grid

std_resid <- resid(mod) / mod$s
outlier <- filter(mpg, abs(std_resid) > 2)
outlier
```

```{r}
ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  geom_line(data = grid, color = "blue", size = 1.5) +
  geom_text(data = outlier, aes(label = model))
```

```{r}
ggplot(mapping = aes(displ, hwy)) +
  geom_point(data = mpg) +
  geom_line(data = grid) +
  geom_text(data = outlier, aes(label = model))
```

Aesthetic mappings

```{r}
# all the same plot result

ggplot(mpg, aes(displ, hwy, color = class)) +
  geom_point()

ggplot(mpg, aes(displ, hwy)) +
  geom_point(aes(color = class))

ggplot(mpg, aes(displ)) +
  geom_point(aes(y = hwy, color = class))

ggplot(mpg) +
  geom_point(aes(displ, hwy, color = class))
```

```{r}
ggplot(mpg, aes(displ, hwy, color = class)) +
  geom_point() +
  geom_smooth(method = "lm", se = FALSE) +
  theme(legend.position = "none")

# one line
ggplot(mpg, aes(displ, hwy)) +
  geom_point(aes(color = class)) +
  geom_smooth(method = "lm", se = FALSE) + #color class set in the point
  theme(legend.position = "none")
```

Setting vs mapping

```{r}
ggplot(mpg, aes(cty, hwy)) +
  geom_point(color = "darkblue")

ggplot(mpg, aes(cty, hwy)) +
  geom_point(aes(color = "darkblue"))
```

```{r}
ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  geom_smooth(aes(color = "loess"), method = "loess", se = FALSE) +
  geom_smooth(aes(color = "lm"), method = "lm", se = FALSE) +
  labs(color = "Method")
```

```{r}
ggplot(mpg, aes(displ, hwy)) +
  geom_rug()
```

```{r}
recent <- economics[economics$date > as.Date("2013-01-01"), ]
ggplot(recent, aes(date, unemploy)) + geom_line()
ggplot(recent, aes(date, unemploy)) + geom_step()
```

```{r}
# very handy
ggplot(mpg, aes(trans, cty)) +
  geom_point() +
  stat_summary(geom = "point", fun = "mean", color = "red", size = 4)

ggplot(mpg, aes(trans, cty)) +
  geom_point() +
  geom_point(stat = "summary", fun = "mean", color = "red", size = 4)
```
```{r}
ggplot(diamonds, aes(price)) + 
  geom_histogram(binwidth = 500)
ggplot(diamonds, aes(price)) + 
  geom_histogram(aes(y = after_stat(density)), binwidth = 500)
```

Standardize area
```{r}
ggplot(diamonds, aes(price, color = cut)) +
  geom_freqpoly(binwidth = 500) +
  theme(legend.position = "none")

ggplot(diamonds, aes(price, color = cut)) +
  geom_freqpoly(aes(y = after_stat(density)), binwidth = 500) +
  theme(legend.position = "none")
```

Position Adjustments
```{r}
dplot <- ggplot(diamonds, aes(color, fill = cut)) +
  xlab(NULL) +
  ylab(NULL) +
  theme(legend.position = "none")

dplot + geom_bar()
dplot + geom_bar(position = "fill")
dplot + geom_bar(position = "dodge")
dplot + geom_bar(position = "identity", alpha = 1/2, color = "grey50")

ggplot(diamonds, aes(color, color = cut)) +
  geom_line(aes(group = cut), stat = "count") +
  xlab(NULL) +
  ylab(NULL) +
  theme(legend.position = "none")
```
```{r}
ggplot(mpg, aes(displ, hwy)) + 
  geom_point(position = "jitter")
ggplot(mpg, aes(displ, hwy)) + 
  geom_point(position = position_jitter(width = 0.05, height = 0.5))
ggplot(mpg, aes(displ, hwy)) + 
  geom_jitter(width = 0.05, height = 0.5)
```