Checking for decimals values in input

I am trying to write a function that wil display an error message if the input is not a whole number IE: the user the value 1.5 for the value of r in the code below.

Thank you.

function [R]=Newreshape(M,r,c)
                                    

Answer 1

[Stephen23]

assert(fix(r)==r,'Input r must be a whole number')

Answer 2

[Adam]

validateattributes( r, { 'numeric' }, { 'scalar', 'integer' } )

Answer 3

[Patirick Legare]

Thanks guys