Course project for getting and cleaning data, course on the data science John Hopkins specialization

The data should be in the same folder as the run_analysis.R

Replace PATH_TO_FILE with your actual path In R: source('/PATH TO FILE/run_analysis.R')

The output file is called tidy_dataset.txt, found in the same folder after running the code.

For each record it is provided a column variable:

• "subject": Is a number representing a test subject who performed the activity. Its range is from 1 to 30.
• "activity": Is the name of the activity performed by the subject. Character values.
• "activity_code": Codef of the activity performed by the subject. Its range is from 1 to 6.

Column variables contains '-XYZ' to denote 3-axial signals in the X, Y and Z directions of the following measurements:

• tBodyAcc-XYZ
• tGravityAcc-XYZ
• tBodyAccJerk-XYZ
• tBodyGyro-XYZ
• tBodyGyroJerk-XYZ
• tBodyAccMag
• tGravityAccMag
• tBodyAccJerkMag
• tBodyGyroMag
• tBodyGyroJerkMag
• fBodyAcc-XYZ
• fBodyAccJerk-XYZ
• fBodyGyro-XYZ
• fBodyAccMag
• fBodyAccJerkMag
• fBodyGyroMag
• fBodyGyroJerkMag

For each measurement, the mean and standard deviation is named with:

• mean()
• std()

Units:

• The angular velocity vector measured by the gyroscope for each window sample. The units are radians/second.
• 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.
• The body acceleration signal obtained by subtracting the gravity from the total acceleration.

• Features are normalized and bounded within [-1,1].