Advanced Summarizing

HI David, I still get that race_ethnicity not found?

I am also running your code, but for some reason I may be doing something wrong, everything works until I try to mutate the race/ethnicity using the str_remove, even when I run your code. I also noticed that we may need to add the dates x2019_2019 in quotation marks, currently in your code, it only has one quotation mark: mutate(race_ethnicity = str_remove(race_ethnicity, "x2018_2019)) %>%

I tried to use your code, please see below and I am not sure what is going one, as the race ethnicity object is not found:

enrollment_by_race_ethnicity_18_19 % select(-contains("grade")) %>% select(-contains("kindergarten")) %>% select(-contains("percent")) %>% pivot_longer(cols = -district_id, names_to = "race_ethnicity", values_to = "number_of_students") %>% mutate(number_of_students = na_if(number_of_students, "-")) %>% mutate(number_of_students = replace_na(number_of_students, 0)) %>% mutate(number_of_students = as.numeric(number_of_students))%>% mutate(race_ethnicity = str_remove(race_ethnicity,"x2018_2019")) mutate(race_ethnicity = case_when( race_ethnicity == "american_indian_alaska_native" ~ "American Indian Alaska Native", race_ethnicity == "asian" ~ "Asian", race_ethnicity == "black_african_american" ~ "Black/African American", race_ethnicity == "hispanic_latino" ~ "Hispanic/Latino", race_ethnicity == "multiracial" ~ "Multi-Racial", race_ethnicity == "native_hawaiian_pacific_islander" ~ "Pacific Islander", race_ethnicity == "white" ~ "White" )) %>% group_by(district_id) %>% mutate(pct = number_of_students / sum(number_of_students)) %>% ungroup()

Thanks, Atty

I have a question about the "My turn" example. You say that you use summarize in the first part (vs. mutate) because you aren't actually adding a new variable. I'm still having trouble understanding this conceptually, and more broadly, the difference between mutate and summarize for functions that can be called in both. I know you aren't adding a new variable in your example, but you are over-writing/replacing. Could you do the same by using summarize to create a total in a new variable? Would that not add to the data frame?

I had several of these problems happen for me too, including console processing code in blue but nothing happening in the data frame to change names (several tries). At one point when I ran David's solution code, all race_ethnicity turned to NA in the entire data frame. I still don't know exactly what happened to make it work, but I do have one small question:

Do the underscores() matter in the removing/renaming? For example with the variable "x2018-19_asian", if I remove x2018-19 (not x2018-19), but then only mutate "asian" (not _asian), what happens to that underscore?

Is there a difference between slice_max() and top_n() ?

Huh, very strange. We can definitely discuss more this week!