Getting_And_Cleaning_Data_Project

The purpose of this project is to demonstrate your ability to collect, work with, and clean a data set.

Review criterialess The submitted data set is tidy. The Github repo contains the required scripts. GitHub contains a code book that modifies and updates the available codebooks with the data to indicate all the variables and summaries calculated, along with units, and any other relevant information. The README that explains the analysis files is clear and understandable. The work submitted for this project is the work of the student who submitted it. Getting and Cleaning Data Course Projectless The purpose of this project is to demonstrate your ability to collect, work with, and clean a data set. The goal is to prepare tidy data that can be used for later analysis. You will be graded by your peers on a series of yes/no questions related to the project. You will be required to submit: 1) a tidy data set as described below, 2) a link to a Github repository with your script for performing the analysis, and 3) a code book that describes the variables, the data, and any transformations or work that you performed to clean up the data called CodeBook.md. You should also include a README.md in the repo with your scripts. This repo explains how all of the scripts work and how they are connected.

One of the most exciting areas in all of data science right now is wearable computing - see for example this article . Companies like Fitbit, Nike, and Jawbone Up are racing to develop the most advanced algorithms to attract new users. The data linked to from the course website 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

Here are the data for the project:

https://d396qusza40orc.cloudfront.net/getdata%2Fprojectfiles%2FUCI%20HAR%20Dataset.zip

You should create one R script called run_analysis.R that does the following.

Merges the training and the test sets to create one data set. Extracts only the measurements on the mean and standard deviation for each measurement. Uses descriptive activity names to name the activities in the data set Appropriately labels the data set with descriptive variable names. From the data set in step 4, creates a second, independent tidy data set with the average of each variable for each activity and each subject. Good luck!

Code Book

For each record it is provided:

• Triaxial acceleration from the accelerometer (total acceleration) and the estimated body acceleration.
• Triaxial Angular velocity from the gyroscope.
• A 561-feature vector with time and frequency domain variables.
• Its activity label.
• An identifier of the subject who carried out the experiment.

The dataset includes the following files:

• 'README.txt'

• 'features_info.txt': Shows information about the variables used on the feature vector.

• 'features.txt': List of all features.

• 'activity_labels.txt': Links the class labels with their activity name.

• 'train/X_train.txt': Training set.

• 'train/y_train.txt': Training labels.

• 'test/X_test.txt': Test set.

• 'test/y_test.txt': Test labels.

The following files are available for the train and test data. Their descriptions are equivalent.

• 'train/subject_train.txt': Each row identifies the subject who performed the activity for each window sample. Its range is from 1 to 30.

• 'train/Inertial Signals/total_acc_x_train.txt': The acceleration signal from the smartphone accelerometer X axis in standard gravity units 'g'. Every row shows a 128 element vector. The same description applies for the 'total_acc_x_train.txt' and 'total_acc_z_train.txt' files for the Y and Z axis.

• 'train/Inertial Signals/body_acc_x_train.txt': The body acceleration signal obtained by subtracting the gravity from the total acceleration.

• 'train/Inertial Signals/body_gyro_x_train.txt': The angular velocity vector measured by the gyroscope for each window sample. The units are radians/second.

Variables Description

tbodyaccmeanx time body accelerometer signal in x direction mean

tbodyaccmeany time body accelerometer signal in y direction mean

tbodyaccmeanz time body accelerometer signal in z direction mean

tbodyaccstdx time body accelerometer signal in x direction standard deviation

tbodyaccstdy time body accelerometer signal in y direction standard deviation

tbodyaccstdz time body accelerometer signal in z direction standard deviation

tgravityaccmeanx gravity accelerometer signal in x direction mean

tgravityaccmeany time gravity accelerometer signal in y direction mean

tgravityaccmeanz time gravity accelerometer signal in z direction mean

tgravityaccstdx time gravity accelerometer signal in x direction standard deviation

tgravityaccstdy time gravity accelerometer signal in y direction standard deviation

tgravityaccstdz time gravity accelerometer signal in z direction standard deviation

tbodyaccjerkmeanx time body accelerometer jerk signal in x direction mean

tbodyaccjerkmeany time body accelerometer jerk signal in y direction mean

tbodyaccjerkmeanz time body accelerometer jerk signal in z direction mean

tbodyaccjerkstdx time body accelerometer jerk signal in x direction standard deviation

tbodyaccjerkstdy time body accelerometer jerk signal in y direction standard deviation

tbodyaccjerkstdz time body accelerometer jerk signal in z direction standard deviation

tbodygyromeanx time body gyroscope signal in x direction mean

tbodygyromeany time body gyroscope signal in y direction mean

tbodygyromeanz time body gyroscope signal in z direction mean

tbodygyrostdx time body gyroscope signal in x direction standard deviation

tbodygyrostdy time body gyroscope signal in y direction standard deviation

tbodygyrostdz time body gyroscope signal in z direction standard deviation

tbodygyrojerkmeanx time body gyroscope jerk signal in x direction mean

tbodygyrojerkmeany time body gyroscope jerk signal in y direction mean

tbodygyrojerkmeanz time body gyroscope jerk signal in z direction mean

tbodygyrojerkstdx time body gyroscope jerk signal in x direction standard deviation

tbodygyrojerkstdy time body gyroscope jerk signal in y direction standard deviation

tbodygyrojerkstdz time body gyroscope jerk signal in z direction standard deviation

tbodyaccmagmean time body gyroscope accelerometer mean signal

tbodyaccmagstd time body gyroscope accelerometer mean standard deviation

tgravityaccmagmean time gravity accelerometer magnitude signal mean

tgravityaccmagstd time gravity accelerometer magnitude signal standard deviation

tbodyaccjerkmagmean time body accelerometer jerk magnitude mean

tbodyaccjerkmagstd time body accelerometer jerk magnitude standard deviation

tbodygyromagmean time body gyroscope magnitude mean

tbodygyromagstd time body gyroscope magnitude standard deviation

tbodygyrojerkmagmean time body gyroscope jerk magnitude mean

tbodygyrojerkmagstd time body gyroscope jerk magnitude standard deviation

fbodyaccmeanx frequency body accelerometer signal in x direction mean

fbodyaccmeany frequency body accelerometer signal in y direction mean

fbodyaccmeanz frequency body accelerometer signal in z direction mean

fbodyaccstdx frequency body accelerometer signal in x direction standard deviation

fbodyaccstdy frequency body accelerometer signal in y direction standard deviation

fbodyaccstdz frequency body accelerometer signal in z direction standard deviation

fbodyaccjerkmeanx frequency body accelerometer jerk signal in x direction mean

fbodyaccjerkmeany frequency body accelerometer jerk signal in y direction mean

fbodyaccjerkmeanz frequency body accelerometer jerk signal in z direction mean

fbodyaccjerkstdx frequency body accelerometer jerk signal in x direction standard deviation

fbodyaccjerkstdy frequency body accelerometer jerk signal in y direction standard deviation

fbodyaccjerkstdz frequency body accelerometer jerk signal in z direction standard deviation

fbodygyromeanx frequency body gyroscope signal in x direction mean

fbodygyromeany frequency body gyroscope signal in y direction mean

fbodygyromeanz frequency body gyroscope signal in z direction mean

fbodygyrostdx frequency body gyroscope signal in x direction standard deviation

fbodygyrostdy frequency body gyroscope signal in y direction standard deviation

fbodygyrostdz frequency body gyroscope signal in z direction standard deviation

fbodyaccmagmean frequency body accelerometer magnitude mean

fbodyaccmagstd frequency body accelerometer magnitude standard deviation

fbodybodyaccjerkmagmean frequency body accelerometer jerk magnitude mean

fbodybodyaccjerkmagstd frequency body accelerometer jerk magnitude standard deviation

fbodybodygyromagmean frequency body gyroscope magnitude mean

fbodybodygyromagstd frequency body gyroscope magnitude standard deviation

fbodybodygyrojerkmagmean frequency body gyroscope jerk magnitude mean

fbodybodygyrojerkmagstd frequency body gyroscope jerk magnitude standard deviation