This document describes the variables in the tidy_set.txt
file.
All variables are mean of other mean or standard deviation features in the raw data.
All variables are normalized and bounded within [-1,1].
The raw data is available here.
The key columns are categorical.
Each key column pair is unique and identify a row in the tidy set. The columns are:
- 1:
subject
- Identifier of the subject (person) who performed the activity.
- Value range
[1:30]
- 2:
activity
- Performed activity.
- Value set:
laying
,sitting
,standing
,walking
,walking_downstairs
,walking_upstairs
The variable columns are continuous in the interval [-1,1]. They are normalized and have no unit.
Each variable represents the mean of a feature in the raw data set, by subject and activity.
The following are the variables and the feature they are based on, in order:
- 3:
mean_time_body_accelerometer_x
: Based ontBodyAcc-mean()-X
. - 4:
mean_time_body_accelerometer_y
: Based ontBodyAcc-mean()-Y
. - 5:
mean_time_body_accelerometer_z
: Based ontBodyAcc-mean()-Z
. - 6:
standard_deviation_time_body_accelerometer_x
: Based ontBodyAcc-std()-X
. - 7:
standard_deviation_time_body_accelerometer_y
: Based ontBodyAcc-std()-Y
. - 8:
standard_deviation_time_body_accelerometer_z
: Based ontBodyAcc-std()-Z
. - 9:
mean_time_gravity_accelerometer_x
: Based ontGravityAcc-mean()-X
. - 10:
mean_time_gravity_accelerometer_y
: Based ontGravityAcc-mean()-Y
. - 11:
mean_time_gravity_accelerometer_z
: Based ontGravityAcc-mean()-Z
. - 12:
standard_deviation_time_gravity_accelerometer_x
: Based ontGravityAcc-std()-X
. - 13:
standard_deviation_time_gravity_accelerometer_y
: Based ontGravityAcc-std()-Y
. - 14:
standard_deviation_time_gravity_accelerometer_z
: Based ontGravityAcc-std()-Z
. - 15:
mean_time_body_accelerometer_jerk_x
: Based ontBodyAccJerk-mean()-X
. - 16:
mean_time_body_accelerometer_jerk_y
: Based ontBodyAccJerk-mean()-Y
. - 17:
mean_time_body_accelerometer_jerk_z
: Based ontBodyAccJerk-mean()-Z
. - 18:
standard_deviation_time_body_accelerometer_jerk_x
: Based ontBodyAccJerk-std()-X
. - 19:
standard_deviation_time_body_accelerometer_jerk_y
: Based ontBodyAccJerk-std()-Y
. - 20:
standard_deviation_time_body_accelerometer_jerk_z
: Based ontBodyAccJerk-std()-Z
. - 21:
mean_time_body_gyroscope_x
: Based ontBodyGyro-mean()-X
. - 22:
mean_time_body_gyroscope_y
: Based ontBodyGyro-mean()-Y
. - 23:
mean_time_body_gyroscope_z
: Based ontBodyGyro-mean()-Z
. - 24:
standard_deviation_time_body_gyroscope_x
: Based ontBodyGyro-std()-X
. - 25:
standard_deviation_time_body_gyroscope_y
: Based ontBodyGyro-std()-Y
. - 26:
standard_deviation_time_body_gyroscope_z
: Based ontBodyGyro-std()-Z
. - 27:
mean_time_body_gyroscope_jerk_x
: Based ontBodyGyroJerk-mean()-X
. - 28:
mean_time_body_gyroscope_jerk_y
: Based ontBodyGyroJerk-mean()-Y
. - 29:
mean_time_body_gyroscope_jerk_z
: Based ontBodyGyroJerk-mean()-Z
. - 30:
standard_deviation_time_body_gyroscope_jerk_x
: Based ontBodyGyroJerk-std()-X
. - 31:
standard_deviation_time_body_gyroscope_jerk_y
: Based ontBodyGyroJerk-std()-Y
. - 32:
standard_deviation_time_body_gyroscope_jerk_z
: Based ontBodyGyroJerk-std()-Z
. - 33:
mean_time_body_accelerometer_magnitude
: Based ontBodyAccMag-mean()
. - 34:
standard_deviation_time_body_accelerometer_magnitude
: Based ontBodyAccMag-std()
. - 35:
mean_time_gravity_accelerometer_magnitude
: Based ontGravityAccMag-mean()
. - 36:
standard_deviation_time_gravity_accelerometer_magnitude
: Based ontGravityAccMag-std()
. - 37:
mean_time_body_accelerometer_jerk_magnitude
: Based ontBodyAccJerkMag-mean()
. - 38:
standard_deviation_time_body_accelerometer_jerk_magnitude
: Based ontBodyAccJerkMag-std()
. - 39:
mean_time_body_gyroscope_magnitude
: Based ontBodyGyroMag-mean()
. - 40:
standard_deviation_time_body_gyroscope_magnitude
: Based ontBodyGyroMag-std()
. - 41:
mean_time_body_gyroscope_jerk_magnitude
: Based ontBodyGyroJerkMag-mean()
. - 42:
standard_deviation_time_body_gyroscope_jerk_magnitude
: Based ontBodyGyroJerkMag-std()
. - 43:
mean_frequency_body_accelerometer_x
: Based onfBodyAcc-mean()-X
. - 44:
mean_frequency_body_accelerometer_y
: Based onfBodyAcc-mean()-Y
. - 45:
mean_frequency_body_accelerometer_z
: Based onfBodyAcc-mean()-Z
. - 46:
standard_deviation_frequency_body_accelerometer_x
: Based onfBodyAcc-std()-X
. - 47:
standard_deviation_frequency_body_accelerometer_y
: Based onfBodyAcc-std()-Y
. - 48:
standard_deviation_frequency_body_accelerometer_z
: Based onfBodyAcc-std()-Z
. - 49:
mean_frequency_body_accelerometer_jerk_x
: Based onfBodyAccJerk-mean()-X
. - 50:
mean_frequency_body_accelerometer_jerk_y
: Based onfBodyAccJerk-mean()-Y
. - 51:
mean_frequency_body_accelerometer_jerk_z
: Based onfBodyAccJerk-mean()-Z
. - 52:
standard_deviation_frequency_body_accelerometer_jerk_x
: Based onfBodyAccJerk-std()-X
. - 53:
standard_deviation_frequency_body_accelerometer_jerk_y
: Based onfBodyAccJerk-std()-Y
. - 54:
standard_deviation_frequency_body_accelerometer_jerk_z
: Based onfBodyAccJerk-std()-Z
. - 55:
mean_frequency_body_gyroscope_x
: Based onfBodyGyro-mean()-X
. - 56:
mean_frequency_body_gyroscope_y
: Based onfBodyGyro-mean()-Y
. - 57:
mean_frequency_body_gyroscope_z
: Based onfBodyGyro-mean()-Z
. - 58:
standard_deviation_frequency_body_gyroscope_x
: Based onfBodyGyro-std()-X
. - 59:
standard_deviation_frequency_body_gyroscope_y
: Based onfBodyGyro-std()-Y
. - 60:
standard_deviation_frequency_body_gyroscope_z
: Based onfBodyGyro-std()-Z
. - 61:
mean_frequency_body_accelerometer_magnitude
: Based onfBodyAccMag-mean()
. - 62:
standard_deviation_frequency_body_accelerometer_magnitude
: Based onfBodyAccMag-std()
. - 63:
mean_frequency_body_body_accelerometer_jerk_magnitude
: Based onfBodyBodyAccJerkMag-mean()
. - 64:
standard_deviation_frequency_body_body_accelerometer_jerk_magnitude
: Based onfBodyBodyAccJerkMag-std()
. - 65:
mean_frequency_body_body_gyroscope_magnitude
: Based onfBodyBodyGyroMag-mean()
. - 66:
standard_deviation_frequency_body_body_gyroscope_magnitude
: Based onfBodyBodyGyroMag-std()
. - 67:
mean_frequency_body_body_gyroscope_jerk_magnitude
: Based onfBodyBodyGyroJerkMag-mean()
. - 68:
standard_deviation_frequency_body_body_gyroscope_jerk_magnitude
: Based onfBodyBodyGyroJerkMag-std()
.
Only direct mean and standard deviation variables are included from the raw data. Examples of features that are not used in the raw data set:
- fBodyAcc-meanFreq()-X
- fBodyAcc-meanFreq()-Y
- fBodyAcc-meanFreq()-Z
- fBodyAccJerk-meanFreq()-X
- fBodyAccJerk-meanFreq()-Y
- fBodyAccJerk-meanFreq()-Z
- fBodyGyro-meanFreq()-X
- fBodyGyro-meanFreq()-Y
- fBodyGyro-meanFreq()-Z
- fBodyAccMag-meanFreq()
- fBodyBodyAccJerkMag-meanFreq()
- fBodyBodyGyroMag-meanFreq()
- fBodyBodyGyroJerkMag-meanFreq()
- angle(tBodyAccMean,gravity)
- angle(tBodyAccJerkMean),gravityMean)
- angle(tBodyGyroMean,gravityMean)
- angle(tBodyGyroJerkMean,gravityMean)
- angle(X,gravityMean)
- angle(Y,gravityMean)
- angle(Z,gravityMean)
The motivation for not including them is that they appear to be based on mean variables but are not primary mean variables themselves.