Re: [math] - Least squares appx. of quadratic equations

2010-12-31 Thread Luc Maisonobe
Le 31/12/2010 19:17, Vladimir Blagojevic a écrit : > Mikkel, > > I looked at the example but I was not able to load my sample data and > find coefficients of a quadratic equation. Lets say that I have data > points for quadratic equation: > double data[][] = { { 0, 1 }, { 1, 6 }, { 2, 17 } }; whic

Re: [math] - Least squares appx. of quadratic equations

2010-12-31 Thread Mikkel Meyer Andersen
Hi, Quick answer. Remember that x*x has to be treated as an additional variable. Think design matrices. Cheers, Mikkel Den 31/12/2010 19.18 skrev "Vladimir Blagojevic" : > Mikkel, > > I looked at the example but I was not able to load my sample data and > find coefficients of a quadratic equation

Re: [math] - Least squares appx. of quadratic equations

2010-12-31 Thread Vladimir Blagojevic
Mikkel, I looked at the example but I was not able to load my sample data and find coefficients of a quadratic equation. Lets say that I have data points for quadratic equation: double data[][] = { { 0, 1 }, { 1, 6 }, { 2, 17 } }; which is in fact y(x) = 1 + 2x + 3x^2 How would I setup either OLS

Re: [math] - Least squares appx. of quadratic equations

2010-12-30 Thread Mikkel Meyer Andersen
Hi, Try to have a look at the examples provided at http://commons.apache.org/math/userguide/stat.html#a1.5_Multiple_linear_regression . Both OLS and GLS are supported. If you have further questions, do not hesitate to ask! Cheers, Mikkel. 2010/12/30 Vladimir Blagojevic : > Hi, > > I am not sure

[math] - Least squares appx. of quadratic equations

2010-12-30 Thread Vladimir Blagojevic
Hi, I am not sure how, if at all, I can use math package to apply least-squares approximation to find coefficients to n-order equation: y = a0*X^0 + a1*X^1 + ... + an*X^n. More specifically, given a set of x,y data points I would like to find quadratic equations that best fits the input data point