Building a candlestick chart (stock chart)

We are just about to make a super leap. Until now we worked with charts that had one data point, two data points, and a few variations on them, and now we are moving into a new world of four data points in every bar. The stock chart is a way to showcase changes in the market in a given time frame (in our example this is one day). Each day stock prices change many times, but the most important factors are the low and high values of the day and the opening and closing prices. A stock analyst needs to be able to see the information quickly and understand overall trends. We are skipping three data points elements, but we will be back to them in the recipe Building a bubble chart in Chapter 4, Let's Curve Things Up.

The worst thing you can do is to assume that the only usage of four dimensions of data is in the stock market. This is where you can come up with the next big thing. Visualizing data in a clean and quick way and converting data into logic...