Data Set Code Book: "Getting and Cleaning Data" Course Project
This project works with the Human Activity Recognition Using Smartphones Dataset (data downloadable here). The raw data was a given and the details of it's capture are beyond the scope of this project.
The data is stored in a text file in a space-delimited table. This data can be read into R with the following command:
tidy.data <- read.table("tidy_data.txt", header=TRUE)
The study included 30 subjects each engaging in 6 activities and the underlying data included numerous statistics for several dozen different measurements. Our study focuses on the measurements that include average and standard deviation statistics, of where there were 33, giving a total of 66 "average measurement" variables in our derived data set.
These "average measurements" are averages taken over the std and mean measurements from the original data set, averaging over the data grouped by Subject and Activity. These measurement variables are named as follows:
Measurement.[Coordinate.]Domain.Statistic
Measurement is the particular type of sensor measurement, optionally followed by a coordinate (X, Y, or Z) for vector measurements.
Domain is "Time" or "Freq" for statistics that are calculated in the time-domain or the frequency (fast-fourier-transform) domain.
Statistic is "Mean" or "StdDev" for the average or the standard deviation of the underlying raw data.
These names are directly derived from the feature names described in the features_info.txt and enumerated in the features.txt files of the original data set.
See the ReadMe.md file for a detailed description of the steps used to derive the resulting data set from the raw data.
| Variable | Description | Type | Values |
|---|---|---|---|
| Subject | Subject ID | factor | Subject_1, Subject_2, ..., Subject_30 |
| Activity | Activity name | factor | Laying, Sitting, Standing, Walking, Walking_Downstairs, Walking_Upstairs |
| BodyAcc.X.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAcc.Y.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAcc.Z.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAcc.X.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAcc.Y.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAcc.Z.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| GravityAcc.X.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| GravityAcc.Y.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| GravityAcc.Z.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| GravityAcc.X.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| GravityAcc.Y.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| GravityAcc.Z.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.X.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.Y.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.Z.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.X.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.Y.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.Z.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.X.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.Y.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.Z.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.X.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.Y.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.Z.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroJerk.X.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroJerk.Y.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroJerk.Z.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroJerk.X.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroJerk.Y.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroJerk.Z.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccMag.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccMag.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| GravityAccMag.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| GravityAccMag.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerkMag.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerkMag.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroMag.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroMag.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroJerkMag.Time.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroJerkMag.Time.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAcc.X.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAcc.Y.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAcc.Z.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAcc.X.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAcc.Y.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAcc.Z.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.X.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.Y.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.Z.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.X.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.Y.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerk.Z.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.X.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.Y.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.Z.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.X.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.Y.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyro.Z.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccMag.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccMag.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerkMag.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyAccJerkMag.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroMag.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroMag.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroJerkMag.Freq.Mean | Average Measurement | numeric | normalized and bounded within [-1,1] |
| BodyGyroJerkMag.Freq.StdDev | Average Measurement | numeric | normalized and bounded within [-1,1] |