Homework 8

Load libraries

For this homework assignment, I will need tidyverse to clean up the dataset, RColorBrewer to select a color scheme for my plot, highcharter to create my plot, and dslabs to obtain the dataset.

library(tidyverse)

## ── Attaching packages ─────────────────────────────────────── tidyverse 1.3.0 ──

## ✓ ggplot2 3.3.2     ✓ purrr   0.3.4
## ✓ tibble  3.0.4     ✓ dplyr   1.0.2
## ✓ tidyr   1.1.2     ✓ stringr 1.4.0
## ✓ readr   1.4.0     ✓ forcats 0.5.0

## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## x dplyr::filter() masks stats::filter()
## x dplyr::lag()    masks stats::lag()

library(RColorBrewer)
library(highcharter)

## Registered S3 method overwritten by 'quantmod':
##   method            from
##   as.zoo.data.frame zoo

library(dslabs)

## 
## Attaching package: 'dslabs'

## The following object is masked from 'package:highcharter':
## 
##     stars

Stars dataset

I selected the stars dataset to visualize. I wanted to order the star types as factors based on their classification in order of increasing temperature. I also removed rows with missing data and used a summary to make sure there was a complete dataset. I saved this dataset as a CSV file to make sharing with others easier.

data("stars")

stars$type <- factor(stars$type, levels = c("M", "K", "G", "F", "A", "B", "O"))
stars <- drop_na(stars)
summary(stars)

##            star      magnitude           temp       type  
##  Altair      : 2   Min.   :-8.000   Min.   : 2500   M:32  
##  *40EridaniA : 1   1st Qu.:-2.150   1st Qu.: 3038   K:16  
##  *40EridaniC : 1   Median : 2.100   Median : 4900   G: 4  
##  *61CygniA   : 1   Mean   : 3.904   Mean   : 8617   F: 7  
##  *61CygniB   : 1   3rd Qu.:11.050   3rd Qu.: 9900   A:13  
##  *70OphiuchiA: 1   Max.   :17.000   Max.   :33600   B:19  
##  (Other)     :85                                    O: 1

write_csv(stars, "stars_dslabs.csv", na="")

Scatterplot

I chose to create a scatterplot with highcharter. I chose the Red-Yellow-Blue color scheme to mimic the color of stars as they increase in temperature. I decided to plot the temperature vs the brightness of the stars and use a tooltip to show the name of each star. The colors also group the stars by their classification.

# set color palette
cols <- brewer.pal(7, "RdYlBu")

my_scatterplot <- highchart() %>%
    hc_add_series(data = stars, type = "scatter", hcaes(x = temp, y = magnitude, group = type)) %>%
    hc_add_theme(hc_theme_darkunica()) %>% 
    hc_colors(cols) %>% 
    hc_xAxis(title = list(text="Temperature (K)")) %>%
    hc_yAxis(title = list(text="Brightness (absolute magnitude)")) %>%
    hc_title(text = "Brightness of a Star as Temperature increases") %>%
    hc_legend(align = "right", title = "Type") %>%
    hc_tooltip(shared = TRUE, pointFormat = "{point.star}", crosshairs = TRUE) %>%
    hc_chart(style = list(fontWeight = "bold"))

my_scatterplot

```