Hello, I have the following problem.(adsbygoogle = window.adsbygoogle || []).push({});

I have a system of differential equations, with two parameters that satisfy certain condition.

0 < 1.5(1-a) < b < 1.

So when I fix the value of a I can find values of b satisfying this and its associated equilibrium point.

When I calculate (with computer) the equilibrium points for this values and plot them I obtain the following:

https://dl.dropboxusercontent.com/u/38427886/plot.png [Broken]

And when I plot them on the same graph I have

https://dl.dropboxusercontent.com/u/38427886/plots.png [Broken]

As you can see, they seem to be on the same curve, so I made a polynomial fit of second degree. Now, from the fact that all the points for different a, seem to have the same behavior I would like to know how they deviate from the fit that I made to the last set (because it has more points to work with).

Here's where I'm stuck, because I don't know exactly what can I do.

The only idea that I have is to take the distance for every point to the curve, then square that, sum all the distances and finally divide for the number of points.

The think is, I want to know if anyone knows an intelligent way to know how well my discrete set of points adjust to a given curve.

P.S. (I know my English is terrible, I apologize)

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# How good is a fit for a set of points?

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