MATLAB integer to roman numeral

I am working on a lab that requires me to convert integers to roman numerals.

I have the following code:

function r = num2rom(x)
d = [ 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1];
c =  {'M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I'};
r = [];
for i = 1:numel(d)
    if x >= d(i)
        z = idivide(num, d(i));
        r = [r, repmat(c(i), z)];
    end
end
end

But I am getting several errors, these are the errors returning:

Undefined function 'ge' for input arguments of type 'cell'.

Error in Lab4>num2rom (line 112)
    if x >= d(i)

Error in Lab4 (line 76)
num = num2rom(num)

I have been scratching my head at this, any help would be appreciated.

[Rik]

There is no ge function anywhere in your question. Please make sure to quote all the code that is needed to reproduce the error, and then paste all the red text here.

Answer 1

[Rik]

I wouldn't hard-code the combinations, but use the rule instead. My proposal would look something like this:

1. convert the char array to a vector (using the cell you defined already)
2. mark all values that apear before a larger value negative
3. sum the vector elements

If you have trouble writing the code, just write a comment.