Help to work with matrix in STATA 12

[Rafaella Stradiotto]

I'm calculating some indexes in the STATA 12 and I'm putting together the schedule so that you can run without error, but in one of those steps I ran into the following error:
matrix operators that return matrices not allowed in this context
r (509);

The commands I'm using were:
gen KK1 = J1 * Z

I'm trying to generate a variable KK1, from the multiplication of another variable J1 and an matrix Z

To generate J1 I used:
gen J1=(1/5564)*QLa
list J1


What am I doing wrong?
Can someone help me?

[Hua Peng (StataCorp)]

Rafaella,

Your question is a general Stata question, hence may get more responses in the General forum.

That said, multiplication between a variable and a Stata matrix is not allowed since it is generally ambiguous. Imaging the following, J1 has 3 observations, Z is a 1 by 4 matrix, do you want the resulted J1*Z to be a 3 by 4 matrix as a 3 by1 matrix multiply a 1 by 4 matrix? How is the result assigned back to a variable if that is the case?

For me or other users to be able offer more help, you need describable what the matrix Z looks like,

mat list Z

and what do you want to get for the resulted KK1.

[Rafaella Stradiotto]

Z is an matrix of dimension (1x5564)
and J1 is a scalar variable according to localities considered (J1j), and has a particular value, for each j (region) total 5564 localities (or region).
The commands to generate Z, I used:
const gene = 1
mkmat const, matrix (1)
matrix V = i '
matrix list V (1x5564)
The matrix V is formed by a matrix a vector of dimension (1x5564) and the S is the matrix of spatial weight (S) of dimension (5564x5564).
matrix Z = V * S
matrix list Z
I want to generate a new variable, called KKK1, from the multiplication of J1 and the matrix Z of dimension (1x5564):
gen KKK1 = J1 * Z
And is giving the following error:
matrix operators that return matrices not allowed in this context
r (509);