Testing Poisson distribution CDF in objective c and get wrong results

Hello, I am using Poisson distribution CDF function in objective c and I am getting different results than the one calculated on the website. For example after inserting 5, 7.3, true as input I am getting 0.7360 and not 0.264043 as it should be.

Any idea on how to debug it or where my problem may be?

Thanks,

Ofer

I would have expected this code to work in objective C, however its possible that they're handling of data types is a little different.

As this function rely upon several other functions, I would test each of these in turn against the values that the relevant CodeCogs pages give. This should narrow down the problem to one or two functions; we'll then look more closely at what is going on.