# Reasons for -1.#IND ?

### » Wed Mar 25, 2009 4:57 pm

hi,
i am wondering about the possible ways to (inadvertendly) set a private variable to -1.#IND (undefined, i presume). i've got some simple TimeDelta-related math in a project, and it occasionally results in objects becoming invisible when their angle property is being calculated as -1.#IND
since the math is really simple, i've got no idea where to start looking. does somebody know the possible causes of this error?

( the cap is here. click & drag to scratch. occasionally bugs out, especially in debug mode & with unlimited framerate )
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### » Wed Mar 25, 2009 4:59 pm

It means you've done something mathematically impossible. Like divide by zero, take the square root of a negative number, et cetera. The object disappears if the angle, width, height, x or y is this value, because it is impossible to determine how to render the object.
Scirra Founder
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### » Wed Mar 25, 2009 5:03 pm

superfast! thank you very much! i'm guessing it is divide by zero, i'll have a close look.
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### » Thu Mar 26, 2009 7:51 pm

A good way to fix a divide by zero is to ensure that the number you are dividing by is over 0 before performing the arithmetic operation by inserting a condition "Value to divide by > 0". This might be common sense, but this is a note for anyone else that gets stuck on this and can't figure it out.
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