In this project, you could find a R script run_analysis.R, it contains the function to implement the data analysis process which required by the coursera lecture Getting and Cleaning Data. Before you assess the program, please read this file first.

1. Please download the data of this project from[https://d396qusza40orc.cloudfront.net/getdata%2Fprojectfiles%2FUCI%20HAR%20Dataset.zip(https://d396qusza40orc.cloudfront.net/getdata%2Fprojectfiles%2FUCI%20HAR%20Dataset.zip)], and unzip it.

2. Please move the folder which contains the required data to the root of this project. You should have the structure like this:

   • Getting-CleaningData-->UCI HAR Dataset-->test
   • -------------------------------------------------------->train
   • -------------------------------------------------------->...

   Or, please specify the path of the folder by using path paramenter.

3. Run the script run_analysis.R and you will get the output (by default, it is output.txt, you can also specify it by using file.name parameter) in the root of this project.

4. If you want to observer the process of this script, please specify parameter debug as TRUE, then you will get some details when you runing it.

1. The data are extracted which only contain mean or std in their column name.
2. The row of the output file indicating 30 different subjects, and the column of the output file indicating activity label and measurements.

The output file is created by the following processes:

1. Read x, y and subject both in train and test folder.
2. Merge train and test data.
3. Label the column of x according to features.txt.
4. Extract colmns of x according to the key words mean and std.
5. Label the column of y, and replace its value with descriptive names.
6. Label the column of subject.
7. Merge x, y and subject into one called data.
8. Split data according to activity_labels.
9. Aggregate data according to subject in each activity.
10. Output result.