--- title: "Example Markdown File" author: "Your Name Here" date: "01/28/2026" output: html_document --- ```{r setup, include=FALSE} knitr::opts_chunk$set(echo = TRUE, eval = TRUE) ``` ## R Markdown This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see . Additionally, there is a useful cheat sheet of commands [here.](https://www.rstudio.com/wp-content/uploads/2015/02/rmarkdown-cheatsheet.pdf) When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this: ### 1-1 ```{r pset1_1, eval=T, echo=T} data('attitude') #Preloaded dataset summary(attitude$critical) #My answer is this as a comment. ``` Or my answer can be written here ### Example: Privileges ```{r, echo = F, eval = T} summary(attitude$privileges) ``` ```{r, echo = T} plot(attitude$learning, attitude$complaints) ``` ## Regularly Scheduled Lab ```{r} library(dplyr) census_data <- read.csv('https://github.com/apodkul/ppol6803_03/raw/main/Data/census_demo.csv') summary(census_data) head(census_data) ``` ### Using Piping ```{r, eval = F, echo = T} glimpse(census_data) # provides summary of the data #... is equivalent to census_data %>% glimpse() # why didn't this one print on the page? ``` ### Creating New Variables ```{r, eval = F, echo = T} census_data %>% mutate(total_aa = AA_MALE + AA_FEMALE) census_data %>% mutate(maj_white = white_alone_perc > .5) ``` ```{r} census_data <- census_data %>% mutate(total_aa = AA_MALE + AA_FEMALE, maj_white = white_alone_perc > .5) ``` ### Subsetting Data ```{r, eval = F, echo = T} census_data %>% select(STNAME, TOT_POP, hispanic_perc) census_data %>% filter(STNAME == 'New Jersey') census_data %>% filter(STNAME != 'New Jersey' | white_alone_perc < .7) ``` ### Joining Data Frames ```{r, eval = F} census_regions <- read.csv('https://github.com/apodkul/ppol6803_03/raw/main/Data/census_regions.csv') census_data %>% select(STNAME, CTYNAME, hispanic_perc) census_data %>% select(STNAME, CTYNAME, hispanic_perc) %>% left_join(y = census_regions, by = c('STNAME' = 'State.Name')) table(census_data$STNAME) table(census_regions$State.Name) ``` ```{r, eval = T, echo = T} census_regions <- read.csv('https://github.com/apodkul/ppol6803_03/raw/main/Data/census_regions.csv') census_data <- census_data %>% left_join(y = census_regions, by = c('STNAME' = 'State.Name')) ``` ### Collapsing ```{r eval=F, echo=F} census_data %>% summarise(Population = sum(TOT_POP)) census_data %>% group_by(Region) %>% summarise(Population = sum(TOT_POP)) ``` ### Reshaping Data ```{r, echo = T} library(tidyr) #Creating a more manageable dataset test_data <- census_data %>% select(STNAME, CTYNAME, TOT_POP, TOT_MALE, TOT_FEMALE) #From wide to long test_data_w <- test_data %>% pivot_longer(cols = TOT_POP:TOT_FEMALE, names_to = "var_name") #Going back (long to wide) test_data_l <- test_data_w %>% pivot_wider(id_cols = STNAME:CTYNAME, names_from = var_name, values_from = value) ```