Welcome to the week three of our course in Programming Visualizations with D3.js. In the previous week, we have seen how we can use the web platform should develop some visualizations and how we can use D3 to manipulate those elements. In the week two, we were able to load some data and then transform this data in simple visualizations. However, some visualizations are more complex and require us to do some more work with the data in order to get to this data that we are looking for, or to the visualization that we're looking for. In this week, we want to show you some of the features in D3 that help you to convert your data to the actual format that you need, and that you can use to draw the visualization that we're looking for. So, for example, we want to start showing you how you can draw lines. So, drawing lines is a bit different from drawing bars or squares when you have each element representing one data point. With lines, the whole line is just a single line but the line itself represent multiple data points. D3 provide us some features that help us to create those lines and to draw those lines, and we will be seeing that throughout this week. We also will show you how you can deal with pies and data charts. Basically here, the big problem is that you want to map the information to angles harder than width and height and those angles has to be complementors. So, you can keep moving around your circle and close the circle at the end. So, D3 provide us some functions that will help us to first compute those angles and transform the data from the original information. So, information that represents the angles of each arc. Finally, we have the arc object that help us to actually draw our arcs since those are more complex to draw than squares or circles. We conclude by working with maps, and maps have a similar problem, so you will get a very complex shape if you are trying to draw the borders of a country or a state for example. So D3 has some features that help us to not only draw those borders, but also convert information from the latitude and longitude space that is basically the sphere space of the Earth to the 2D plane where you're trying to draw. We will be able to go to some different projections and see how we can use those projections to draw information of the map on the screen. Finally, how we can apply data on top of those maps in order to show the actual data that I'm looking to communicate to my users. So, at the end of this week, we will have the assessment where you have to code and to come up with solutions that use some of the features that we saw throughout this week. So, let's get started.