| title | author | date | output |
|---|---|---|---|
README |
Xiaoyun Yang |
Thursday, May 21, 2015 |
html_document |
Step 1:Reading
read.table is used to read the .txt file as R objects
Step 2:Merging
I used the rbind command to merge the data since there are no repetitive subjects between train and test data sets and this will save some processing time also.
Step 3:Extraction
grep function is used to select the columns with variables which contain "mean" or "std";
Step 4:Rename
Rename the variable with descriptive name given in feature.txt; convert the activity code into activity labels
Step 5:Attach
Attach the subject and activity column to the data set
Step 6:Average
Average each variable grouped by subject and activity
Step 7:Remove
Remove extra columns introduced by aggregate function
step 8:Write
Write the data set to .txt file