Note: column names from the original dataset have special characters (like '-()') replaced with '.' because of column name restrictions
subject
The subject number whom the measurements were obtained from. There were 30 subjects in the test
activity
The activity the subject performed while the measurements were obtained - in the study there were 6 activities Values:
| Original Code | Code Description Found in tidyds.txt |
|---|---|
| 1 | WALKING |
| 2 | WALKING_UPSTAIRS |
| 3 | WALKING_DOWNSTAIRS |
| 4 | SITTING |
| 5 | STANDING |
| 6 | LAYING |
The following columns are all means or standard deviations of the raw accelerometer and gyroscope signals
From the original dataset file features_info.txt:
The features selected for this database come from the accelerometer and gyroscope 3-axial raw signals tAcc-XYZ and >tGyro-XYZ. These time domain signals (prefix 't' to denote time) were captured at a constant rate of 50 Hz. Then they >were filtered using a median filter and a 3rd order low pass Butterworth filter with a corner frequency of 20 Hz to >remove noise. Similarly, the acceleration signal was then separated into body and gravity acceleration signals >(tBodyAcc-XYZ and tGravityAcc-XYZ) using another low pass Butterworth filter with a corner frequency of 0.3 Hz.
Subsequently, the body linear acceleration and angular velocity were derived in time to obtain Jerk signals (tBodyAcc>Jerk-XYZ and tBodyGyroJerk-XYZ). Also the magnitude of these three-dimensional signals were calculated using the >Euclidean norm (tBodyAccMag, tGravityAccMag, tBodyAccJerkMag, tBodyGyroMag, tBodyGyroJerkMag).
Finally a Fast Fourier Transform (FFT) was applied to some of these signals producing fBodyAcc-XYZ, fBodyAccJerk-XYZ, >fBodyGyro-XYZ, fBodyAccJerkMag, fBodyGyroMag, fBodyGyroJerkMag. (Note the 'f' to indicate frequency domain signals).
These signals were used to estimate variables of the feature vector for each pattern: '-XYZ' is used to denote 3-axial signals in the X, Y and Z directions.
tBodyAcc.mean...X
tBodyAcc.mean...Y
tBodyAcc.mean...Z
tGravityAcc.mean...X
tGravityAcc.mean...Y
tGravityAcc.mean...Z
tBodyAccJerk.mean...X
tBodyAccJerk.mean...Y
tBodyAccJerk.mean...Z
tBodyGyro.mean...X
tBodyGyro.mean...Y
tBodyGyro.mean...Z
tBodyGyroJerk.mean...X
tBodyGyroJerk.mean...Y
tBodyGyroJerk.mean...Z
tBodyAccMag.mean..
tGravityAccMag.mean..
tBodyAccJerkMag.mean..
tBodyGyroMag.mean..
tBodyGyroJerkMag.mean..
fBodyAcc.mean...X
fBodyAcc.mean...Y
fBodyAcc.mean...Z
fBodyAcc.meanFreq...X
fBodyAcc.meanFreq...Y
fBodyAcc.meanFreq...Z
fBodyAccJerk.mean...X
fBodyAccJerk.mean...Y
fBodyAccJerk.mean...Z
fBodyAccJerk.meanFreq...X
fBodyAccJerk.meanFreq...Y
fBodyAccJerk.meanFreq...Z
fBodyGyro.mean...X
fBodyGyro.mean...Y
fBodyGyro.mean...Z
fBodyGyro.meanFreq...X
fBodyGyro.meanFreq...Y
fBodyGyro.meanFreq...Z
fBodyAccMag.mean..
fBodyAccMag.meanFreq..
fBodyBodyAccJerkMag.mean..
fBodyBodyAccJerkMag.meanFreq..
fBodyBodyGyroMag.mean..
fBodyBodyGyroMag.meanFreq..
fBodyBodyGyroJerkMag.mean..
fBodyBodyGyroJerkMag.meanFreq..
angle.tBodyAccMean.gravity.
angle.tBodyAccJerkMean..gravityMean.
angle.tBodyGyroMean.gravityMean.
angle.tBodyGyroJerkMean.gravityMean.
angle.X.gravityMean.
angle.Y.gravityMean.
angle.Z.gravityMean.
tBodyAcc.std...X
tBodyAcc.std...Y
tBodyAcc.std...Z
tGravityAcc.std...X
tGravityAcc.std...Y
tGravityAcc.std...Z
tBodyAccJerk.std...X
tBodyAccJerk.std...Y
tBodyAccJerk.std...Z
tBodyGyro.std...X
tBodyGyro.std...Y
tBodyGyro.std...Z
tBodyGyroJerk.std...X
tBodyGyroJerk.std...Y
tBodyGyroJerk.std...Z
tBodyAccMag.std..
tGravityAccMag.std..
tBodyAccJerkMag.std..
tBodyGyroMag.std..
tBodyGyroJerkMag.std..
fBodyAcc.std...X
fBodyAcc.std...Y
fBodyAcc.std...Z
fBodyAccJerk.std...X
fBodyAccJerk.std...Y
fBodyAccJerk.std...Z
fBodyGyro.std...X
fBodyGyro.std...Y
fBodyGyro.std...Z
fBodyAccMag.std..
fBodyBodyAccJerkMag.std..
fBodyBodyGyroMag.std..
fBodyBodyGyroJerkMag.std..