How to calculate regression with dummy variables?

Hi, I am trying to use 2nd degree polynomial regression with dummy variables. Which function should I use? Thanks for any help!

Answer 1

[the cyclist]

If you have the Statistics and Machine Learning Toolbox, take a look at the fitlm function.

You might also find the dummyvar command useful for creating dummy variables.

Take a look at Regression with Categorical Covariates for an example.

[JFz]

Thanks! But fitlm is linear model. I need polynomial (2 degree or 3 degree). What function should I use? Should I use fitnlm or polyfit? Thanks again! Jennifer

[the cyclist]

Do you mean that you have polynomials for your independent variables, like

y = a + b*x + c*x^2

That is a linear model. "Linear" refers to the coefficients, not the powers (or whatever) of the variables.

On the other hand, something like

y = a + x^b

is nonlinear in the coefficient. Yes, you would need fitnlm for something like that.