What is wrong with my "if is integer" code

I have a function roman= dectoroman(number) I want first to test out for if the number is an interger or not and I tried using the isinteger function but somehow its not working and not really sure why.

 if isinteger(number) 
   x = [ 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1]; % Array of intergers (x)
  y =  {'M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I'};% array of strings equalling intergers above respectivly (y)
  roman=[];%Instantiating 
  for ii = 1:numel(x) 
          number >= x(ii);  
          roman = [roman,repmat(y{ii},1,fix(number/x(ii)))];
          number = rem(number,x(ii));
else
error('error')
       end
             end
  end

wondering if there was anyway to test if its not an integer so i can just go if its to an integer ---> error end

[Azzi Abdelmalek]

where is your if?

[Walter Roberson]

Azzi, the first line, "if isinteger(number)"

Answer 1

[Azzi Abdelmalek]

because

isinteger(1)=0  % for example

try

if fix(a)==a

Answer 2

[Walter Roberson]

A number is an integer if mod(number,1) == 0