Indeed, findchangepts is a Signal Processing Toolbox function that was introduced in 2016a. If you're simply looking for steps larger than some threshold, you can use diff, which tells you the difference between each element and the one before it. For example,
y = [1 2 3 200 201 200 2 1]
The step sizes using diff are
dy = [0 diff(y)]
dy =
0 1 1 197 1 -1 -198 -1
If you want to find every step bigger than 100,
changepoints = find(abs(dy)>100)
changepoints =
4 7
The fourth and seventh elements in y jumped or dropped by a magnitude of more than 100.
