worksheet column has been set to either x or y
if ycol is not given, assume only one x column is available
grori('datareza',3);
setxori('datareza',1);
grori('datareza',3);
grori('datareza');
grori('datareza');
setxori('datareza',3);
grori('datareza');
grori('datareza',[2:2:4],'reza');
grori('datareza',[2:2:4]);