Constructing a flowchart

In the previous recipe, Building smart diagrams, we used predefined chart types. In a case when we would need more flexibility, we can do it ourselves from scratch. It's also not too hard, and it's a very good way of learning to draw with TikZ.

We will create a flowchart depicting the decision-making procedure for choosing a math environment.

Similar to what we saw in our description diagram of the first recipe, we will do the following:

1. Define shapes and colors.

2. Place nodes using a matrix.

3. Insert labeled arrows between selected nodes.

Of course, whatever is done in each step may be modified at any time. It's usual to place nodes and arrows at first, and then start fine-tuning shapes and colors.

So let's tackle it. Go through the following steps, and also look at the graphical output shown after them to understand the meaning of your drawing tasks:

1. Start with a document class:

   \documentclass{article}

2. We load the geometry package and specify a vertical margin so that the long...