LucasVidal/data-cleaning-assignment

Programming assignment for Data Cleaning course

Getting and Cleaning Data Course Project

Programming Assignment - Human Activity Recognition Using Smartphones Data Set

Behavior

When running the script, the indicated operations will ocurr:

1. Download data if needed
2. Produce a tidy dataset, assigning proper variable names, having one table per observational unit
3. Transforms the activity numbers into their labels to have more declarative data.
4. Creates a second tidy dataset, which contains all variables averaged grouped by activity and subject

Functions

download_data()

1. Download the dataset from the source
2. Unzips the data into a "data" folder

read_data(data.frame) -> data.frame

Solution to requests (1) and (4)

1. Loads the variable names dataset
2. Loads the test data, binding the subject column and the activity number column. Assigns the variable names read in step 1.
3. Loads the train data, binding the subject column and the activity number column. Assigns the variable names read in step 1.
4. Binds both test and train datasets into one.

extract_mean_sd(data.frame) -> data.frame

Solution to request (2)

Extracts columns which names matches "mean" or "std", while also keeping subject and activity columns

labels_to_factors(data.frame) -> data.frame

Solution to request (3)

Replaces label integer column with the correspondent activity names

produce_averages(data.frame) -> data.frame

Solution to request (5)

Average all variables grouped by activity and subject.