iOS Plotting graph on iphone

Using CGContext functions, I am trying to plot a line graph for a particular month. In the graph we have weekdays on x-axis and respective data on y-axis. I have to plot this graph for several month in such a way that all the graphs appears inside a scrollview so that the user can scroll them.
All this requires use of CGContext method so before going into it deeply I would like to know what effect it will have on application performance?
As plotting line graph is very urgent

I have already created about 80% of chart. My only point of worry is as I have to show a scrollview containing UIViews on which these charts are being plooted [Each UIView will have one chart on it]. Will it cause any performance related problem as I have to create chart for each month of the year. Though I think of limiting the number of pages [UIViews with charts] to some fixed count when that count exceeds then remove those UIViews and add another set of UIViews to the scrollview. Usig a lot of CGContext methods in drawRect of UIView will cause any performance problem that is my point of worry
Thanks
Arnieterm