## Helpful tips before we start

### TROUBLESHOOTING: Common new user mistakes we have seen

- Check the file path -- is the file there?  
- Typos (R is **case sensitive**, `x` and `X` are different)  
- Open ended quotes, parentheses, and brackets     
- Deleting part of the code chunk  
- For any function, you can write `?FUNCTION_NAME`, or `help("FUNCTION_NAME")` to look at the help file

### R Projects

R Projects can help you keep files organized and avoid issues with working directories. Check out our resource here: https://daseh.org/resources/R_Projects.html


## Lab

In this lab you can use the interactive console to explore or **Knit** the document. 
Remember anything you type here can be "sent" to the console with Cmd-Enter (OS-X) or Ctrl-Enter (Windows/Linux) in an R code chunk.

```{r}
# Load the necessary package
library(readr)
```

### 1.1

Use the manual import method (File > Import Dataset > From Text (`readr`)) to read in Haloacetic Acids (HAA5) Exposure for WA Populations on Public Water Systems data from this URL:

https://daseh.org/data/HAA5_Exposure_for_WA_Public_Water_Systems_data.csv.

These data were collected by the Washington Tracking Network. You can learn more about the data here: https://fortress.wa.gov/doh/wtn/WTNPortal/#!q0=674

### 1.2

What is the dataset object called? You can find this information in the Console or the Environment. Enter your answer as a comment using `#`.

```{r 1.2response}

```

### 1.3

Preview the data by clicking the table button in the Environment. How many observations and variables are there? Enter your answer as a comment using `#`.

```{r 1.3response}

```

### 1.4

Read Haloacetic Acids (HAA5) Exposure for WA Populations on Public Water Systems data from https://daseh.org/data/HAA5_Exposure_for_WA_Public_Water_Systems_data.csv.
and assign it to an object named `exposure`. Use the code structure below.

```
# General format
library(readr)
# OBJECT <- read_csv(FILE)
```

```{r 1.4response}

```

### 1.5

Take a look at the data. Do these data objects (`HAA5_Exposure_for_WA_Public_Water_Systems_data` and `exposure`) appear to be the same? Why or why not?

```{r 1.5response}

```

### 1.6

Learn your working directory by running `getwd()`. This is where R will look for files unless you tell it otherwise.

```{r 1.6response}

```


# Practice on Your Own!

### P.1

Load the `readxl` package with the `library()` command. 

If it is not installed, install it via: `RStudio --> Tools --> Install Packages`. You can also try `install.packages("readxl")`.

```{r P.1response}

```

### P.2

Download the dataset of nitrate levels in the public water systems: https://daseh.org/data/Nitrate_Exposure_for_WA_Public_Water_Systems_data.xlsx file to `nitrate.xlsx` by running the following code chunk. This only downloads the file, it does NOT bring the file into R.

```{r}
download.file(
  url = "https://daseh.org/data/Nitrate_Exposure_for_WA_Public_Water_Systems_data.xlsx",
  destfile = "nitrate.xlsx",
  overwrite = TRUE,
  mode = "wb"
)
```

Note: the "wb" option makes sure the file can be read correctly on Windows and Apple machines.

### P.3

Use the `read_excel()` function in the `readxl` package to read the `nitrate.xlsx` file and call the output `nitrate`. 

```{r P.3response}

```

### P.4

Run the following code - is there a problem? How do you know?

```{r}
exposure <- read_delim("https://daseh.org/data/HAA5_Exposure_for_WA_Public_Water_Systems_data.csv", delim = "\t")
exposure
```

```{r P.4response}

```
