 |
 |
Dear Johannes, You can try downsampling your data and then the default filter order might work. In general I don't think the filter order matters too much for this particular application because you don't necessarily need a sharp cutoff so as long as it works it should be fine. Vladimir On 17 Nov 2011, at 16:26, Johannes Gehrig <[log in to unmask]> wrote: Dear DCM-experts, I'm trying to use DCM to model phase-coupling. In the beta band it seems to work. Unfortunately in lower bands I get the error: "Calculated filter coefficients have poles on or outside the unit circle and will not be stable. Try a higher cutoff frequency or a different type/order of filter." I changed the filter order from 5 to 4 now I'm able to calculate phase-coupling in the alpha-band when I change it to 3 I'm able to go down to 2Hz. Do I still get reasonable results by cahnging the filter order? Should I use the same order for all frequency-bands I'm going to analyse or adapt it to the highest possible filter order per frequency-band? Thanks! Johannes SMS schreiben mit WEB.DE FreeMail - einfach, schnell und kostenguenstig. Jetzt gleich testen! *http://f.web.de/?mc=021192*<http://f.web.de/?mc=021192>