Thanks Artur I think this is it. I found out that for some reason the first-to-be-generated vector "q" in my script below had lower dimension than the sample size. I don't know why that happened yet. But when I managed to obtain a "q" vector with the correct dimension, then the line

<<series qqq = sumr(q.*qq)>>

worked just fine, and gave me qqq as a series.

Thanks!

Alecos Papadopoulos PhD
Athens University of Economics and Business
web: alecospapadopoulos.wordpress.com/
cell:+30-6945-378680
skype:alecos.papadopoulos

Date: Fri, 26 Apr 2019 21:09:27 +0200
From: Artur Tarassow <atecon@posteo.de>
Subject: [Gretl-users] Re: Series from matrix
To: gretl-users@gretlml.univpm.it
Message-ID: <44aa51da-ae2c-5bdb-4362-3c61fad929f3@posteo.de>
Content-Type: text/plain; charset=iso-8859-7; format=flowed

Am 26.04.19 um 21:06 schrieb Alecos Papadopoulos:

Good afternoon.

Has something changed in Gretl related to how we get data out of a 
matrix column and into a series?

I had an old mle script that included

series qqq = sumr(q.*qq)

where the right hand side is  a column vector. It had worked in the 
past, but it doesn't appear to work any more, I get

<<Incompatible types in assignment: series = matrix . The formula 
'series qqq = sumr(q.*qq)' produced an error on execution>>

Hi Alecos,

I've experienced some similar behaviour a while ago. Could you check 
please that the length of the resulting vector exactly meets the length 
of the currently selected data set?

Artur