Can't find the Dataset Boston in MASS

Wenwen · October 10, 2018, 5:18pm

I am trying to load Boston into the environment from package MASS. For some reason, it keeps telling me there's no such data. I have tried:

library(MASS)
data(Boston)

library(MASS)
boston <- Boston
dim(boston)

The result is NULL

I downloaded the newest version of R-studio.

Could anyone help me with this problem? Thank you.

rywhale · October 10, 2018, 5:30pm

Weird works fine for me. Maybe trying reinstalling MASS?

library(MASS)
boston <- Boston
dim(boston)
#> [1] 506  14

^{Created on 2018-10-10 by the reprex package (v0.2.1)}

Wenwen · October 10, 2018, 5:33pm

I have redownloaded it, but still not working.

rywhale · October 10, 2018, 5:35pm

Well that's about the extent of my troubleshooting knowledge. For the sake of others, can you post the output of sessionInfo()

Wenwen · October 10, 2018, 6:04pm

nwerth · October 10, 2018, 6:09pm

The data() function doesn't return a loaded object. It loads the objects into your environment, assigns it the predetermined name, and then returns a character vector of the name(s).

So Boston <- data(Boston) does the following:

data(Boston) loads the dataset and assigns it to the Boston variable. Then it returns the vector "Boston".
Boston <- ... takes that character vector and assigns it to the Boston variable, replacing the dataset with "Boston".

If you just use data(Boston) as it's own line, it'll work how you want.

Wenwen · October 10, 2018, 6:12pm

Both:
library(MASS)
Boston <- Boston
dim(Boston)

library(MASS)
Boston <- "Boston"
dim(Boston)

return to Null

nwerth · October 10, 2018, 6:18pm

If dim(Boston) returns NULL, that means the Boston object already exists. Otherwise, you'd get an error. Because there's a local version, R uses that instead of looking into any attached packages.

Restart your R session (CTRL + SHIFT + F10) and try it again.

Wenwen · October 10, 2018, 6:41pm

Thank you so much for the help!