GettingAndCleaningData

ReadDataFileFile function:-> for reading dataset and merging all files

PrefixPath:-> path for datafile.

The SuffixFname:->File name suffix to create the complete file name.

This also subsets the data to extract only the measurements on the mean and standard deviation for each measurement.

The required columns in the subset is determined by selecting only those columns that have either "mean()" or "std()" in their names.

Subsetting is done early on to help reduce memory requirements.

read test data set, in a folder named "test", and data file names suffixed with "test"

read test data set, in a folder named "train", and data file names suffixed with "train"

Merge both train and test data sets

Also make the column names nicer

Add the activity names as another column

Combine training and test data sets and add the activity label as another column

Create a tidy data set that has the average of each variable for each activity and each subject.

Create the tidy data set and save it on to the named file