R Tutorial : Visualizing numerical data

Want to learn more? Take the full course at https://learn.datacamp.com/courses/introduction-to-data at your own pace. More than a video, you'll learn hands-on coding & quickly apply skills to your daily work. --- The most logical and most useful first step of any data analysis is an exploratory analysis. And a very important and informative component of exploratory data analysis is visualization. You will learn a lot more about data visualization in the exploratory data analysis course, so we won't go into too much detail on data visualization in this course. Let's, however, make a simple scatter plot to visualize the relationship between two numerical variables so that you can get some exposure to constructing plots in R and how to interpret them. There are many ways of visualizing data in R, but in this course we will focus on using the ggplot2 package. We chose ggplot2 because this package makes modern looking hassle-free plots that take care of fiddly details like drawing legends. Additionally, once you learn how to make simple bivariate plots, it is easy to extend your code to create a visualization that displays the relationship between many variables at once without having to learn too much more syntax. Another attractive feature of ggplot2 is that it works iteratively, as in, you can start with a layer showing the raw data, and then add layers of annotations and statistical summaries. This is an attractive feature for learning the syntax, as we can go step-by-step, starting with a simple plot and slowly building up to more complex ones. Let's load the ggplot2 package using the library function. We'll visualize the relationship between the math and science scores of the students in the High School and Beyond dataset. Here is the complete code to create this plot. Let's pause for a moment and review the code. We use the ggplot function to create plots. The first argument is the data frame containing the data we wish to plot. In the aesthetics arg