Who worked with charts?

Question

JavaScript

Hello! I work for a company that sells ventilation equipment, in particular industrial fans, and now I'm working on a fan selection program. The program works, but there is a problem, the problem is that my program draws straight lines, my program draws such a graph:

In the catalog, this line of an identical fan is slightly curved


: and draws a line, this line is straight.

I'm wondering why this line is curved (arc-shaped)? Of course, I can make this line of the curve stupidly put the third point on the graph and fit it to the graph from the magazine, but I want it to be wise and as it should be!

The people who faced such a task? Is there a calculation formula?

In the company where I work, I can’t explain anything intelligibly to me, they say it should be a curve and that’s it!

Answer 1

You can get the formula by approximating several points, but it's easier to just adjust the result - points A, B and some kind of curvature. https://habrahabr.ru/post/264191/