This project contains one R script, run_analysis.R, that:

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

This script will detect whether the file activity.zip is present in the current working directory. If it isn't, it will retrieve the data file.

If the /data subdirectory is present in the working directory, the script will assume the raw file has been unpacked. Otherwise it will unpack the activity.zip file into /data.

Produces a file mean_observed_values.txt in the working directory as output.

In bullet five, "each variable" is taken to mean only those variables extracted in bullet two.