This file describes how run_analysis.R script works.
- First, unzip the data from https://d396qusza40orc.cloudfront.net/getdata%2Fprojectfiles%2FUCI%20HAR%20Dataset.zip.
- Make sure the folder "UCI HAR Dataset" and the run_analysis.R script are both in the current working directory.
- Second, use source("run_analysis.R") command in RStudio.
- Third, you will find two output files are generated in the current working directory:
- merged_data.txt (7.9 Mb): it contains a data frame called cleanedData with 10299*68 dimension.
- cleanData_with_mean.txt (220 Kb): it contains a data frame called result with 180*68 dimension.
- Finally, use data <- read.table("cleanData_with_mean.txt") command in RStudio to read the file. Since we are required to get the average of each variable for each activity and each subject, and there are 6 activities in total and 30 subjects in total, we have 180 rows with all combinations for each of the 66 features.