Using a smooth plot to connect points

TikZ can plot functions for us, either using a set of coordinate values or a mathematical parametrization. We will learn a lot about plotting in the next chapter; for now, let’s have just a first quick look at coordinate plots.

We will work with the set of points from the previous section. As said, we may need more points for more accuracy, so let’s look at Figure 12.2 again and choose two additional coordinates on the curve, such as two peak values (-1.3, 0.86) and (1.3, -0.86). TikZ can do a simple plot through all those points by the plot operation as follows:

\draw plot coordinates {
  (-3,-2.4) (-2,0.4) (-1.3,0.86) (-0.4,0.4)
  (0.4,-0.4) (1.3,-0.86) (2,-0.4) (3,2.4) };

These commands generate a sequence of straight linear segments:

Figure 12.5 – A plot through given coordinates

That’s not smooth yet, but add the smooth keyword as an option to plot:

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