Example_Assign1

The following is a barebones example of what a completed assignment 1 that meets all of the non-Piazza related criteria.

Read and load libraries

The code below will first load the tidyverse library and read in the flouride and arsenic data. notice that I don’t have any warnings or messages in my html file. That is because I set code chunk to warning=FALSE and message=FALSE.

library(tidyverse)
library(knitr)
fluoride <- read.csv(url("http://jamessuleiman.com/teaching/datasets/fluoride.csv"),
                    stringsAsFactors = FALSE)
arsenic <- read.csv(url("http://jamessuleiman.com/teaching/datasets/arsenic.csv"),
                    stringsAsFactors = FALSE)

Join tables

The assignment states: “Prepare a report that has an interesting narrative that focuses on a subset of the data you find interesting that includes both arsenic and fluoride data.” and also explicitly requests: “you must create a data frame or tibble that joins both arsenic and fluoride by location.”. So first, I’ll join the tables and display a table of the flouride and arsenic levels for the five highest combined arsenic + fluoride locations with at least 50 wells tested. I use kable make the table prettier.

arsenic_fluoride <- arsenic %>% inner_join(fluoride, by = "location")
arsenic_fluoride <- arsenic_fluoride %>%
  mutate(combined_avg_level = (n_wells_tested.x * percent_wells_above_guideline.x +
                                 n_wells_tested.y * percent_wells_above_guideline.y)/
           (n_wells_tested.x + n_wells_tested.y))
combined_wells_top_5 <- arsenic_fluoride %>% select(location,
                                  n_wells_tested_arsenic = n_wells_tested.x,
                                  n_wells_tested_flouride = n_wells_tested.y,
                                  percent_high_arsenic = percent_wells_above_guideline.x,
                                  percent_high_fluoride = percent_wells_above_guideline.y,
                                  combined_avg_level) %>% 
  arrange(desc(combined_avg_level)) %>%
  slice(1:5)
kable(combined_wells_top_5)

location	n_wells_tested_arsenic	n_wells_tested_flouride	percent_high_arsenic	percent_high_fluoride	combined_avg_level
Otis	53	60	39.6	30.0	34.50265
Manchester	275	276	58.9	3.3	31.04955
Surry	181	175	40.3	18.3	29.48539
Blue Hill	241	209	42.7	9.6	27.32689
Mercer	33	32	36.4	15.6	26.16000

Chart

The assignment also requires:

• a chart with the code that creates it not displayed - I’ll set echo = false in the code chunk to accomplish this.
• a list with two bullets – this is the second bullet on the two bullet list.

To keep things simple, I’ll just to a column chart of the top five table above ordered by combined average.

Notice, you don’t see the code that generated the chart above.