Is it possible to write a function according to the schedule?

Question

Mathematics

What's up, software.
If there is a graph (any), you can write a function on it?
I heard from a person the expression "Yes, what kind of schedule is this? You can't even write a function using it," at that moment he was just looking at the rating of programming languages.
If it is possible, send at once any trivial example.

Answer 1

You should look towards the following three terms: interpolation, extrapolation, approximation. A trivial example would be the construction of the equation of a straight line from two points, this is already analytic geometry.

Answer 2

It depends on what knowledge and approaches you have. You can go the way of analytics and look for similar features. A whole branch of calculus and linear algebra deals with this. You can go the way of algorithms and try to bring the picture to some kind of dense, there are sections for this in numerical methods. You can use a probabilistic way and look for a function as a probability density (or their sum).