task3_soap_flexdashboard.Rmd

---
title: "Simple Soap Report"
author: "Emi Tanaka"
output: 
  flexdashboard::flex_dashboard:
    orientation: rows
    vertical_layout: fill
---

```{r setup, include=FALSE}
library(flexdashboard)
dat <- read.table("data/soap.txt", header=T)
```

Row {.tabset .tabset-fade}
-----------------------------------------------------------------------


### Why R-Ladies

<h1>Why R-Ladies</h1>

* R-Ladies promotes gender diversity within the R community. 
* R package contribution is predominately by (cis)-male. 
* Diversity is a great step forward for science and the community in general. This is also true for the agricultural area where maintaining genetic diversity for food security is *vital*.
* **What would you hope to learn from coming to R-Ladies?**

### Introduction

This data set was obtained from [OzDASL](http://www.statsci.org/data/oz/soap.html).

According to Rex Boggs:


> I had a hypothesis that the daily weight of my bar of soap [in grams] in my shower wasn't a linear function, the reason being that the tiny little bar of soap at the end of its life seemed to hang around for just about ever. I wanted to throw it out, but I felt I shouldn't do so until it became unusable. And that seemed to take weeks. Also I had recently bought some digital kitchen scales and felt I needed to use them to justify the cost. I hypothesized that the daily weight of a bar of soap might be dependent upon surface area, and hence would be a quadratic function ... .

The data ends at day 22. On day 23 the soap broke into two pieces and one piece went down the plughole.

Row {data-height=500}
-----------------------------------------------------------------------

### Scatter Plot

```{r}
plot(dat$Day, dat$Weight, xlab="Day", ylab="Weight (in g)", main="Soap Usage")
fit <- lm(Weight ~ Day, data=dat) # fit a simple linear regression
abline(coef(fit)) # draw the fitted line
```

### Residual Plot

```{r}
plot(dat$Day, resid(fit), xlab="Day", ylab="Residual", main="Residual Plot") 
abline(h=0)
```