/Getting-and-Cleaning-Data-Project

Primary LanguageR

Getting and Cleaning Data Project

  • Unzip the source ( https://d396qusza40orc.cloudfront.net/getdata%2Fprojectfiles%2FUCI%20HAR%20Dataset.zip )

    into a folder on your local drive, say C:\Users\yourname\Documents\R\

  • Put run_analysis.R to C:\Users\yourname\Documents\R\UCI HAR Dataset\

  • in RStudio: setwd("C:\\Users\\yourname\\Documents\\R\\UCI HAR Dataset\\")

    and then: source("run_analysis.R")

  • The latter will run the R script, it will read the dataset and write these files:

    merged_clean_data.txt -- 8.35 Mb, a 10299x68 data frame

    data_set_with_the_averages.txt -- 0.225 Mb, a 180x68 data frame

    The script normally runs for ~30 seconds, but the exact number depends on your system.

  • Use data <- read.table("data_set_with_the_averages.txt") to read the latter. It is 180x68 because there are 30 subjects and 6 activities, thus "for each activity and each subject" means 30*6=180 rows. Note that the provided R script has no assumptions on numbers of records, only on locations of files.