This directory contains an R script called run_analysis.R for the Getting and Cleaning Data course project. The script requires these data files:
- X_train.txt
- X_test.txt
- y_train.txt
- y_test.txt
- subject_train.txt
- subject_test.txt
- activity_labels.txt
- features.txt
The script run_analysis.R first loads all the features from X_train.txt and X_test.txt and collates them in a single file. Then it adds the target data - the activities, and the subject identifiers.
With this data it calculates means and standard deviations of each of the 561 measured features and saves them in the file means.and.sds.txt.
The script finally calculates means and sds for every subject and for every activity separately and stores all of these means and sds in the file all.means.and.sds.txt.
In all.means.and.sds.txt , as well as the 561 named features, there are columns Class.Type which distinguishes between statistics for a subject and statistics for an activity, the identifier that identifies a subject or activity (Identifier) and the specific statistic (Statistic).
Numerical labels are used for subjects, the text labels from activity_labels.txt for labelling the six activities, and the labels from features.txt for labelling features. Note: the latter may need renaming for some types of further processing.