Borrower Race and Ethnicity by Year (II)
In this exercise, you'll use both iotools and bigtabulate to tabulate borrower race and ethnicity by year.
Bu egzersiz
Scalable Data Processing in R
kursunun bir parçasıdırEgzersiz talimatları
iotools and bigtabulate are loaded in your workspace.
- Create a function
make_table()that reads in chunk as a matrix and then tabulates it by borrower race and year. - Use
chunk.apply()to import the data from the file connection we created for you. - Convert
race_year_tableto a data frame.
Uygulamalı interaktif egzersiz
Bu örnek kodu tamamlayarak bu egzersizi bitirin.
# Open a connection to the file and skip the header
fc <- file("mortgage-sample.csv", "rb")
readLines(fc, n = 1)
# Create a function to read chunks
make_table <- function(chunk) {
# Create a matrix
m <- ___(chunk, sep = ",", type = "integer")
colnames(m) <- mort_names
# Create the output table
___(m, c("borrower_race", "year"))
}
# Import data using chunk.apply
race_year_table <- ___(fc, make_table)
# Close connection
close(fc)
# Cast it to a data frame
rydf <- ___(race_year_table)
# Create a new column Race with race/ethnicity
rydf$Race <- race_cat