Human Activity Recognition database built from the recordings of 30 subjects performing activities of daily living (ADL) while carrying a waist-mounted smartphone with embedded inertial sensors. This dataset is available here for download and use for analysis. I have downloaded the data through the run_analysis.R script and used for analysis.
1. Download the dataset: Download the dataset here and extract the files under "UCI HAR Dataset" folder
2. Read and Assign data to Variables:
-a. Read data from features.txt file and assing to features variable
-b. Read data from activity_labels.txt file and assing to activities variable
-c. Read data from subject_test.txt file and assing to subject_test variable
-d. Read data from X_test.txt file and assing to x_test variable
-e. Read data from Y_test.txt file and assing to y_test variable
-f. Read data from subject_train.txt file and assing to subject_train variable
-g. Read data from X_train.txt file and assing to x_train variable
-h. Read data from Y_train.txt file and assing to y_train variable
3. Merge both (test and train) data to create one set of data
-a. rbind() function is used for merging x_train, x_test, y_train, y_test, subject_train,
subject_test data and created new variables X, Y and Subject
-b. cbind() fucntion is used for merging X, Y and Subject data into Merged_Data
4. Extracts only the mean and standard deviation for each measurement
-a. TidyData is created by subsetting Merged_Data
-b. Selecting only columns: subject, code and the measurements on the mean and standard
deviation(std) for each measurement
5. Use descrtptive activity names for the activities in the data set
-a. Entire numbers in code column of the TidyData replaced with corresponding activity taken from
second column of the activities variable
6. Label the dataset variables with descriptive/meaningful names
-a. code column in TidyData renamed to activities
-b. "Acc" in column name replaced by "Accelerometer"
-c. "Gyro" in column name replaced by "Gyroscope"
-d. "BodyBody" in column name replaced by "Body"
-e. "Mag" in column name replaced by "Magnitude"
-f. All start with character f in column’s name replaced by "Frequency"
-g. All start with character t in column’s name replaced by "Time"
7. 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
-a. AnalyzedData is created by sumarizing TidyData taking the means of each
variable for each activity and each subject, after groupped by subject and activity.
-b. Export AnalyzedData into AnalyzedData.txt file.