The function requires plyr package
addSuffix - creates a suffix, used in the finaldataheaders to add ".mean"
First step is to get the data. The assumption is that "UCI HAR Dataset" folder is in the working directory. Get data files X_test.txt and Y_test.txt and subject_test.txt from both "test" and "train" subfolders into one file.
activitylabels - Creates activity labels to be used in the sensordatameanstd to name the activities in the dataset.
featurelabels - get the features labels from the features.txt
1 - merge the training and test datasets 2 - extract measurements on the mean and standard deviation 3 - name the activities in the dataset (uses activitylabels) 4 - label the dataset with the descriptive names (uses addSuffix) 5 - create a tidy dataset with the average of each variable for each activity and each subject.