<div dir="ltr">Hi Roberto --<div><br><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div>have you tried using the vstack command implemented in pymvpa?<br></div><div><a href="http://www.pymvpa.org/generated/mvpa2.base.dataset.vstack.html#mvpa2.base.dataset.vstack" target="_blank">http://www.pymvpa.org/generated/mvpa2.base.dataset.vstack.html#mvpa2.base.dataset.vstack</a></div></div></blockquote><div><br></div><div>That looks like just the thing.  I'll try it, thank you! </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div></div></div></blockquote></div><br></div></div><div class="gmail_extra">S</div></div>