Course Project
This is a code book for explaining the variable names. We have 180 observations of 68 variables in the ouput of the R script. Here are the explanations for the variable names in the tidy_set.txt.
The subject, tagged as 1 to 30, comes from the test and train set.
The body signals captured by the smarphone can be classified into 6 categories: WALKING, WALKING_UPSTARIS, WALKING_DOWNSTRAIRS, SITTING, STANDING, LAYING.
These signals are measured by the acclerometer and gyroscope and they fall into two domains: Time （prefix ‘time’） and Frequency (prefix ‘frequency). These set of body signals are estimated by the mean() and std() function. Here is the list of the signal names from the tidy_set.txt.
timeBodyAccmeanX
timeBodyAccmeanY
timeBodyAccmeanZ
timeBodyAccstdX
timeBodyAccstdY
timeBodyAccstdZ
timeGravityAccmeanX
timeGravityAccmeanY
timeGravityAccmeanZ
timeGravityAccstdX
timeGravityAccstdY
timeGravityAccstdZ
timeBodyAccJerkmeanX
timeBodyAccJerkmeanY
timeBodyAccJerkmeanZ
timeBodyAccJerkstdX
timeBodyAccJerkstdY
timeBodyAccJerkstdZ
timeBodyGyromeanX
timeBodyGyromeanY
timeBodyGyromeanZ
timeBodyGyrostdX
timeBodyGyrostdY
timeBodyGyrostdZ
timeBodyGyroJerkmeanX
timeBodyGyroJerkmeanY
timeBodyGyroJerkmeanZ
timeBodyGyroJerkstdX
timeBodyGyroJerkstdY
timeBodyGyroJerkstdZ
timeBodyAccMagmean
timeBodyAccMagstd
timeGravityAccMagmean
timeGravityAccMagstd
timeBodyAccJerkMagmean
timeBodyAccJerkMagstd
timeBodyGyroMagmean
timeBodyGyroMagstd
timeBodyGyroJerkMagmean
timeBodyGyroJerkMagstd
frequencyBodyAccmeanX
frequencyBodyAccmeanY
frequencyBodyAccmeanZ
frequencyBodyAccstdX
frequencyBodyAccstdY
frequencyBodyAccstdZ
frequencyBodyAccJerkmeanX
frequencyBodyAccJerkmeanY
frequencyBodyAccJerkmeanZ
frequencyBodyAccJerkstdX
frequencyBodyAccJerkstdY
frequencyBodyAccJerkstdZ
frequencyBodyGyromeanX
frequencyBodyGyromeanY
frequencyBodyGyromeanZ
frequencyBodyGyrostdX
frequencyBodyGyrostdY
frequencyBodyGyrostdZ
frequencyBodyAccMagmean
frequencyBodyAccMagstd
frequencyBodyBodyAccJerkMagmean
frequencyBodyBodyAccJerkMagstd
frequencyBodyBodyGyroMagmean
frequencyBodyBodyGyroMagstd
frequencyBodyBodyGyroJerkMagmean
frequencyBodyBodyGyroJerkMagstd