Getting and Cleaning Data Project

Objectives

This project will create an R script called run_analysis.R that does the following:

1. Merges the training and the test sets to create one data set.
2. Extracts only the measurements on the mean and standard deviation for each measurement.
3. Uses descriptive activity names to name the activities in the data set
4. Appropriately labels the data set with descriptive activity names.
5. Creates a second, independent tidy data set with the average of each variable for each activity and each subject.

Procedures

1. Download the R script run_analysis.R onto your hard drive, preferrably your R working directory
2. Run source("run_analysis.R") in R. The program assumes a folder called data exists in your working directory, and a subfolder called UCI HAR Dataset folder under the data folder containing the unzipped data downloaded from the given web site.
3. If data or UCI HAR Dataset does not exist in your working directory, the program will create them, download the necessary UCI_HAR_data.zip file from the given web site, and then unzip to the UCI HAR Dataset subfolder.
4. The program generates two tidy datasets, one in CSV format and the other in TXT format in the data folder. The UCI_HAR_tidy.csv is easier to read as a spreadsheet, and the UCI_HAR_tidy.txt file is for project submission.

Dependencies

run_analysis.R file assumes "plyr" package is already installed.