Hi I tried to run the following and it keeps giving me the following. Can somebody help me fix it.

close all clear all

%Question # 1D

alpha=1 beta=2 sigma=2 BetaOLS_Vector=ones(1000,2) for i=1:1000 x=normrnd(2,1,[200,1]); e=normrnd(0,sigma,[200,1]); y=alpha + beta*x +e(i); Con=ones(200,1); xn=[Con x]; BetaOLS_Vector(i)= inv(xn'*xn)*xn'*y end

In an assignment A(I) = B, the number of elements in B and I must be the same.

Error in ProblemTwoQuestionOne (line 16) BetaOLS_Vector(i)= inv(xn'*xn)*xn'*y

[José-Luis]

http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

Answer 1

[Roger Stafford]

The problem here is that inv(xn'*xn)*xn'*y has two elements in a size 2 x 1 vector, while you are trying to place them in a single element position in BetaOLS_Vector(i). Matlab doesn't like that.

Probably you mean this:

   BetaOLS_Vector(i,:)= inv(xn'*xn)*xn'*y;

[Solomon Gofere]

Thanks Roger, I corrected based on your recommendation, it works!

Answer 2

[Image Analyst]

BetaOLS_Vector(i must be a single number. Evidently inv(xn'*xn)*xn'*y is not a single number. Check the dimensions of xn and y and make sure it works out to a scalar.

[Solomon Gofere]

Thanks, I have now some idea about where it went wrong!