[R] How to create a warning inside the factorial function for decimal numbers

[peter dalgaard]

You might check that n %% 1 == 0.

(Factorials do exist for fractional numbers -- check e.g. factorial(6.5). And please don't send HTML because, well, you can see the result below)

- pd

> On 1 Jun 2020, at 12:49 , Vahid Borji <vahid.borji65 using gmail.com> wrote:
> 
> I am writing a code for the factorial function. My code is as follows:
> 
>> f<- function(n){+ factorial <- 1+ if( n < 0 )+ print("Factorial of negative numbers is not possible")+ else if( n == 0 )+ print("Factorial of 0 is 1")+ else {+ for(i in 1:n)+ factorial <- factorial * i+ print(paste("Factorial of ",n," is ",factorial))+ }+ }
> 
> My problem with this code is for decimal numbers as input. For example for
> f(6.5) my code computes 720, but we know 6.5 ! does not exist. For decimal
> numbers like, or sqrt(2) I would like to see a message like
> 
> "The factorial for this number does not exist".
> 
> How can I fix this problem in my code?
> 
> 	[[alternative HTML version deleted]]
> 
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-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
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