In jr-packages/jrBig: Jumping Rivers: R for Big Data

Exercise 1

1. Load the ff package r library("ff")
2. Obtain the filename of the example data set r filename = jrBig::get_rand() and compare the read times of read.csv.ffdf and read.csv

ffx = read.csv.ffdf(file = filename, header = TRUE)
dd = read.csv(file = filename, header = TRUE)

Exercise 2

Suppose we have $n$ chunks. Can you think of how we could calculate

• The mean
• The variance
• The median

If it makes things easier, set $n=5$

jr-packages/jrBig documentation built on Jan. 1, 2020, 2:02 p.m.