caokyhieu / Assignment-for-cleaning-data

Train Data:

• First, use data.table package, read X_train.txt and features.txt to tables, take value from features table to make column names for X_train table.
• Read file y_train.txt with column name is "activity"
• join two tables above (X_train and y_train) to make trainData table

Test Data

• Similar like train data, make testData.

Concatenate trainData to testData by rbind() -> dat table

read activity_labels.txt to table with column names "code" and "activity.labels"

mege two tables (dat and acitivty_labels) with parameter sort=FALSE, eliminate the first column (code) -> mergeData

select features with mean() and std() (mean and standard diviation) in features table(66 features) plus two features "activity" and "activity.labels"

make subset table from mergeData table by 68 features above

use lapply() to calculate everage values of features for each person and each activity.