Michael Galarnyk mGalarnyk

Exploratory Data Analysis Quiz 1 (JHU) Coursera

Question 1

Which of the following is a principle of analytic graphics?

Make judicious use of color in your scatterplots (NO)
Don't plot more than two variables at at time (NO)

Exploratory Data Analysis Quiz 2 (JHU) Coursera

Question 1

Under the lattice graphics system, what do the primary plotting functions like xyplot() and bwplot() return?

nothing; only a plot is made
an object of class "lattice"

Exploratory Data Analysis Project 1

This assignment uses data from the UC Irvine Machine Learning Repository, a popular repository for machine learning datasets. In particular, we will be using the “Individual household electric power consumption Data Set” which I have made available on the course web site:

Dataset: Electric power consumption [20Mb]
Description: Measurements of electric power consumption in one household with a one-minute sampling rate over a period of almost 4 years. Different electrical quantities and some sub-metering values are available.

library("data.table")

Exploratory Data Analysis Project 2 (JHU) Coursera

Unzipping and Loading Files

library("data.table")
path <- getwd()
download.file(url = "https://d396qusza40orc.cloudfront.net/exdata%2Fdata%2FNEI_data.zip"
              , destfile = paste(path, "dataFiles.zip", sep = "/"))
unzip(zipfile = "dataFiles.zip")

R Programming Quiz 1 (JHU) Coursera

github repo for rest of specialization: Data Science Coursera

Question 1

R was developed by statisticians working at...

Answer

The University of Auckland

R Programming Quiz 2

github repo for rest of specialization: Data Science Coursera

Question 1

Suppose I define the following function in R

R Programming Quiz 3

github repo for rest of specialization: Data Science Coursera

Question 1

Take a look at the 'iris' dataset that comes with R. The data can be loaded with the code:

library(datasets)

R Programming Quiz 4

github repo for rest of specialization: Data Science Coursera

Question 1

What is produced at the end of this snippet of R code?

set.seed(1)

	# Getting and Cleaning Data Project John Hopkins Coursera
	# Author: Michael Galarnyk

	# 1. Merges the training and the test sets to create one data set.
	# 2. Extracts only the measurements on the mean and standard deviation for each measurement.
	# 3. Uses descriptive activity names to name the activities in the data set
	# 4. Appropriately labels the data set with descriptive variable names.
	# 5. 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.

	# Load Packages and get the Data

	<html>
	<header><title>This is title</title></header>
	<body>
	Hello world
	</body>
	</html>