Obj-C: Calculate the standard deviation of an NSArray of NSNumber objects?

Question

If I have an NSArray of NSNumber objects, how do I calculate the standard deviation of the numbers in the array?

Answer 1

Here's a link to an algorithm you could use. I don't know of any built-in Objective C statistics libraries, so I would just implement the algorithm myself. The link does it in Java, but it should be easy to convert.