The problem lies in the following functions:
8 UIKit -[UILabel setFrame:] + 233 9 Infectious -[SusceptibilityHistoryController buildHistogram:] + 9648
You call label.frame = ... and probably calculate the value in some way, and the result is NaN, which means "not a number", and, as you correctly assumed, this could be the result of the "divide by zero" operation, But it can appear for many other reasons: http://en.wikipedia.org/wiki/NaN
Go through the "buildHistogram:" function, find the call to either "setFrame" or ".frame =" and find how the calculated position becomes NaN. If there is division, it is likely to be division by zero.
source share