Dear Gretl Community,<br><br>I&#39;m trying to perform a X-12-Arima analysis in a series but I&#39;m getting this error message:<br><br>&quot;Error messages generated from processing the X-12-ARIMA spec file teste.spc:<br>

<br>ERROR: Multiplicative or log additive seasonal adjustment cannot be performed when<br>preadjustment factors are derived from a regARIMA model for data which have not been<br>log transformed.<br><br>Check the values for the power or function arguments of the transform spec and mode<br>

of the x11 spec.&quot;<br><br>Looking at my data (attached) I think I&#39;d found what&#39;s going on: the series range goes<br>from 2001:01 to 2012.12, but my valid observations finish at 2010:07. The remaining<br>observations are empty entries.<br>

<br>The X-12-Arima are trying to use these empty entries in the analysis and due to this<br>are returning the error message.<br><br>In my humble opinion, it would be nice if X-12-Arima adjust the series range automatically,<br>

just like Gnuplot does when we plot the series.<br><br>What do you think?<br><br>Best regards,<br>-- <br>Henrique C. de Andrade<br>Doutorando em Economia Aplicada<br>Universidade Federal do Rio Grande do Sul<br><a href="http://www.ufrgs.br/ppge">www.ufrgs.br/ppge</a><br>