Dear friends - I have a data.frame hh with columns Na ID fit time 135 13 134.7945 60 133 13 132.9084 120 131 13 131.0848 180 129 13 129.3372 240 127 13 127.5546 300 126 13 125.8162 360 124 13 124.1836 420 123 13 122.6077 480 When I use lattice xyplot(Na+fit~time|ID,hh,type=c("smooth","g","p"), auto.key=list(lines=TRUE)) the curve for Na after time 240 takes some wild swings, and a warning is issued Warning messages: 1: pseudoinverse used at 482.1 2: neighborhood radius 242.1 3: reciprocal condition number 0 4: at 360 5: radius 14400 6: all data on boundary of neighborhood. make span bigger 7: There are other near singularities as well. 14400 8: pseudoinverse used at 482.1 9: neighborhood radius 242.1 10: reciprocal condition number 0 11: at 360 12: radius 14400 13: all data on boundary of neighborhood. make span bigger 14: There are other near singularities as well. 14400 Otherwise for the whole dataset of 16 pigs it works quite OK - but only this pig number 13 makes troubles. I wonder what occurs. Best wishes Troels -- Troels Ring - - Department of nephrology - - Aalborg Hospital 9100 Aalborg, Denmark - - +45 99326629 - - tring at gvdnet.dk