Charts with input values

I would like to create a graph. It would have a table of four numeric inputs that someone could put their own values into and then click a button. The page would then use these values and apply a few formula to them to create a graph below it.

My Question:

What is the best method to do this? I have seen there are a number of chart tools for wordpress, although as far as I can tell they are for charts with fixed values instead of ones where people can put in their own to generate a graph. I don’t know if it makes a difference, but the graph produced would have curves and have an x and y axis, where the y axis can go into negative values.