OK, this is unrelated to the asymmetry question of this thread, but
still has to do with the band option.
I get an error (with gretl 2016c) about missing values when I do this.
That information in the message is correct, but AFAIK gretl's 'gnuplot'
command normally deals with missing values simply by not showing
anything there, so in that sense the non-handling looks like a bug to me.
thanks,
sven