Code Book
The original data represent data collected from the accelerometers from the Samsung Galaxy S smartphone. A full description is available at the site where the data was obtained:
http://archive.ics.uci.edu/ml/datasets/Human+Activity+Recognition+Using+Smartphones
Variables
subject.id: The subject who performed the activity. activity.description: The activity performed. Following variables contains the average of each variable with same name in the original dataset, for each activity and each subject.
tBodyAcc-mean()-X tBodyAcc-mean()-Y tBodyAcc-mean()-Z tBodyAcc-std()-X tBodyAcc-std()-Y tBodyAcc-std()-Z tGravityAcc-mean()-X tGravityAcc-mean()-Y tGravityAcc-mean()-Z tGravityAcc-std()-X tGravityAcc-std()-Y tGravityAcc-std()-Z tBodyAccJerk-mean()-X tBodyAccJerk-mean()-Y tBodyAccJerk-mean()-Z tBodyAccJerk-std()-X tBodyAccJerk-std()-Y tBodyAccJerk-std()-Z tBodyGyro-mean()-X tBodyGyro-mean()-Y tBodyGyro-mean()-Z tBodyGyro-std()-X tBodyGyro-std()-Y tBodyGyro-std()-Z tBodyGyroJerk-mean()-X tBodyGyroJerk-mean()-Y tBodyGyroJerk-mean()-Z tBodyGyroJerk-std()-X tBodyGyroJerk-std()-Y tBodyGyroJerk-std()-Z tBodyAccMag-mean() tBodyAccMag-std() tGravityAccMag-mean() tGravityAccMag-std() tBodyAccJerkMag-mean() tBodyAccJerkMag-std() tBodyGyroMag-mean() tBodyGyroMag-std() tBodyGyroJerkMag-mean() tBodyGyroJerkMag-std() fBodyAcc-mean()-X fBodyAcc-mean()-Y fBodyAcc-mean()-Z fBodyAcc-std()-X fBodyAcc-std()-Y fBodyAcc-std()-Z fBodyAcc-meanFreq()-X fBodyAcc-meanFreq()-Y fBodyAcc-meanFreq()-Z fBodyAccJerk-mean()-X fBodyAccJerk-mean()-Y fBodyAccJerk-mean()-Z fBodyAccJerk-std()-X fBodyAccJerk-std()-Y fBodyAccJerk-std()-Z fBodyAccJerk-meanFreq()-X fBodyAccJerk-meanFreq()-Y fBodyAccJerk-meanFreq()-Z fBodyGyro-mean()-X fBodyGyro-mean()-Y fBodyGyro-mean()-Z fBodyGyro-std()-X fBodyGyro-std()-Y fBodyGyro-std()-Z fBodyGyro-meanFreq()-X fBodyGyro-meanFreq()-Y fBodyGyro-meanFreq()-Z fBodyAccMag-mean() fBodyAccMag-std() fBodyAccMag-meanFreq() fBodyBodyAccJerkMag-mean() fBodyBodyAccJerkMag-std() fBodyBodyAccJerkMag-meanFreq() fBodyBodyGyroMag-mean() fBodyBodyGyroMag-std() fBodyBodyGyroMag-meanFreq() fBodyBodyGyroJerkMag-mean() fBodyBodyGyroJerkMag-std() fBodyBodyGyroJerkMag-meanFreq() Transformations
Created the train and test datasets adding them the subject and the activity. Merged the training and the test sets to create one data set. Set the column names Extracted only the measurements on the mean and standard deviation for each measurement. Set descriptive activity names to name the activities in the data set Created the second, independent tidy data set with the average of each variable for each activity and each subject.