Thread: blank lines in chart

i have a collection of data showing attainment of children. Am able to plot a line graph against time for an individual pupil, but when time is in future or there is missing data the line drops to zero, very off putting, any way of doing two things
1 dates/plots in future line is blank or does not plot
2 missing data leaves a space in line

any help much appreciated
steve

many thnaks, interpolation seems to do the trick, although when there is a gap of more than two piueces of data the line goes weird, however, my application should not have more than two missing pieces together.