tikz pictures rendering

[Pol]

Hi all, 
​I don't know  if this a lyx software issue or a tikz programming issue (i 
am
rather new to tikz)

I would like to lower a bit the circle in the 'in line' command:

 \tikz \draw (0,-9pt) circle (4pt);

so that the circle appear shifted a little lower, with respect to the text
line it is in.
​inserting the latex command:

\tikz \draw (0,-9pt) circle (4pt);

​obtains:
1 - ​the ​picture​​,​ on the lyx display​,​ effectively shifted downward, but 
its lower part has been cut away.​ I would have a full circle in the text 
line.
​
​2 - T​he picture appears unmoved, in the pdf rendering

Any comments will be appreciated

thank you

paolo m.