matrix A = { 1, 2, 3; 4, 5, 6 }
A

scalar a12 = 2
matrix A = { 1, a12, 3; 4, 5, 6 }
A

nulldata 10
series a1 = normal()
series a2 = uniform()

matrix A = { a1, a2 }
A

list alist = a1 a2
matrix A = { alist }
A

matrix A = { a1, abs(a1) }
A

matrix I5 = I(5)
I5

matrix A = ones(2,3)
A
matrix A = zeros(3,2)
A
matrix A = mnormal(5,2)
A

matrix idx = { 1, 4, 5 }
matrix B = A[idx,]
B

open engel
matrix y = { foodexp }
matrix X = { const income }
matrix b = inv(X'X)*X'y
b

ols foodexp const income
series uhat1 = $uhat
gnuplot uhat1 --time-series --with-lines

series yhat = $coeff(const)+$coeff(income)*income + normal(0,$sigma)
ols yhat 0 2
series uhat2 = $uhat
gnuplot uhat2 --time-series --with-lines