Dear Gretl Useres!<br>I&#39;ve 30 variables and want to generate vector n 
with number of valid observations for each variable. I&#39;m using &#39;ok&#39; 
function but something is wrong (see script below). Probably &#39;$i&#39; is not
 taken as a i-th variable but as a series containg only &quot;i&quot;. What do you
 think about it? How to be sure that &#39;$i&#39; is taken as a i-th variable?  <br>
<br>&lt;hansl&gt;<br>n=zeros(30,1)<br>loop i=1..30<br>    a=sum(ok($i))<br>    n[i,1]=a<br>endloop<br>print n<br clear="all"><br><br>Regards,<br>Mariusz<br clear="all"><br>-- <br>Mariusz Doszyń<br>