Can someone help me write out this equation for chi-square please

I am having trouble writing this equation out in matlab, am a beginner. This is my attempt so far: CS= sum(((y-m)./err_y).^2). Any help would be much appreciated!

Answer 1

[Alan Stevens]

As long as y, m and err_y have the same number of elements then your expression should work ok.

[Kelley Kehoe]

So for what I am trying to do I have two different function models. the first yields an output of 17,800 for CS and the model doesn't fit the data points in a plot but the second does more so and yields 500 for CS. Does this sound reasonable?

[Alan Stevens]

It is reasonable that the better fitting model produces a smaller value of chi-squared.

Your expression for chi-square looks somewhat unusual to me

(see https://www.statisticshowto.com/probability-and-statistics/chi-square/ for example), however, I'm no statistics expert.

[Kelley Kehoe]

yes it is somewhat irregular, this is an assignment for class the equation differs slightly.