other thoughts about bar graphs that may be obvious:
if you're using an array of strings they should follow the pattern "x ", "xx ","xxx ",.. so that trailing spaces overwrite what was left over from last time. If you use the for loop and single character print you want to do the same thing--print spaces over the old bar. Using clear takes 2 milliseconds and then you have to reconstruct the whole screen.
A program that does bar graphs is likely to want to divide somewhere and if you can work it out so that >> will do, that is a LOT faster. so putting a short label on the line and having 16 or 32 segments in the bar may have a big payoff in speed.