---
title: "Influence"
output: html_notebook
---
```{r}
library(tidyverse)
```


```{r}
ggplot(cars,aes(speed,dist)) + geom_point() + geom_smooth()
```

```{r}
cars.fit <- lm(dist~speed,data=cars)
cars.fit
```
```{r}
plot(cars.fit)
```

```{r}
influence(cars.fit)
```
$$ b_i = \frac{x_i - \bar x}{Var(x)}$$

```{r}
bi <- (cars$speed-mean(cars$speed))/var(cars$speed)
plot(bi,influence(cars.fit)$hat)
```
```{r}
plot(bi,influence(cars.fit)$coef[,2]) 
```
```{r}
ggplot(cars,aes(speed,dist)) + geom_point() + geom_smooth()
```
```{r}
ggplot(cars,aes(speed,dist)) + geom_jitter() + geom_smooth()
```
```{r}
library(rstanarm)
```
```{r}
ggplot(mtcars,aes(vs,mpg)) + geom_jitter(height=0,width=.05) + geom_smooth(method="lm")
```