Animation is surprisingly easy. The sliderInput() function, which provides an HTML widget that allows us to select a number along a line, has an optional animation function that will increment a variable by a set amount every time a specified unit of time elapses. This allows you to very easily produce a graphic that is animated.
In the following example, we are going to look at the monthly graph and plot a linear trend line through the first 20% of the data (0-20% of the data). Then, we are going to increment the percentage value that selects the portion of the data by 5% and plot a linear through that portion of data (5-25% of the data). Then, increment by 10-30% and plot another line, and so on.
The slider input is set up as follows, with an ID, label, minimum value, maximum value, initial value, step between values, and the animation options, giving the delay in...