how to make a function that convert roman number to arabic number

Hi everyone;

I am going to attempt that question:

"function called roman that takes a string representing an integer between 1 and 20 inclusive using Roman numerals and returns the Arabic equivalent as a number of type uint8. If the input is illegal or its value is larger than 20, roman returns 0 instead. The rules for Roman numerals can be found here: http://en.wikipedia.org/wiki/Roman_numerals. Use the definition at the beginning of the page under the “Reading Roman Numerals” heading. In order to have unambiguous one-to-one mapping from roman to Arabic numbers, consider only the shortest possible roman representation as legal. Therefore, only three consecutive symbols can be the same (IIII or VIIII are illegal, but IV and IX are fine), and a subtractive notation cannot be followed by an additive one using the same symbols making strange combinations, such as IXI for 10 or IXX for 19, illegal also."

i am using that code:

function myarabic=roman(n)
switch n
    case 'I'
        myarabic=1;
    case 'II'
        myarabic=2;
    case 'III'
        myarabic=3;
    case 'IV'
        myarabic=4;
    case 'V'
        myarabic=5;
    case 'VI'
        myarabic=6;
    case 'VII'
        myarabic=7;
    case 'VIII'
        myarabic=8;
    case 'IX'
        myarabic=9;
    case 'X'
        myarabic=10;
    case 'XI'
        myarabic=11;
    case 'XII'
        myarabic=12;
    case 'XIII'
        myarabic=13;
    case 'XIV'
        myarabic=14;
    case 'XV'
        myarabic=15;
    case 'XVI'
        myarabic=16;
    case 'XVII'
        myarabic=17;
    case 'XVIII'
        myarabic=18;
    case 'XIX'
        myarabic=19;
    case 'XX'
        myarabic=20;
    otherwise
             myarabic=0;
end
end

but when i test this code i got an error :

   Feedback: Your function made an error for argument(s) 'I'

      Your solution is _not_ correct.

Thanks in advance for assistance....

[Muhammad Usman Saleem]

Guide me about my corrections. Very thanks in advance...

Answer 1

[Muhammad Usman Saleem]

I find the error : we have to return uint8 arabic number in output..

[Christos Vyzantios]

this syntax ?? otherwise myarabic=0; or myarabic=uint8;

[Christos Vyzantios]

I write this code based above but the problem stil exists

function myarabic=roman(n)
switch n
    case 'I'
        myarabic=1;
    case 'II'
        myarabic=2;
    case 'III'
        myarabic=3;
    case 'IV'
        myarabic=4;
    case 'V'
        myarabic=5;
    case 'VI'
        myarabic=6;
    case 'VII'
        myarabic=7;
    case 'VIII'
        myarabic=8;
    case 'IX'
        myarabic=9;
    case 'X'
        myarabic=10;
    case 'XI'
        myarabic=11;
    case 'XII'
        myarabic=12;
    case 'XIII'
        myarabic=13;
    case 'XIV'
        myarabic=14;
    case 'XV'
        myarabic=15;
    case 'XVI'
        myarabic=16;
    case 'XVII'
        myarabic=17;
    case 'XVIII'
        myarabic=18;
    case 'XIX'
        myarabic=19;
    case 'XX'
        myarabic=20;

      otherwise
          myarabic=('uint8'); 

          %myarabic=0; 

             % myarabic=uint8; %#ok<NASGU>

           % myarabic='uint8'; %
  end
  end

[Christos Vyzantios]

No the problem still exists...The grader does not accept the solution and i dont know why...

[Walter Roberson]

The code there does not return the numbers as uint8() numbers, and the code there does not return uint8(0) for invalid strings.

Answer 2

[Ingrid]

how do you test your code?

When I do

roman('I')

ans =

       1

or

roman('XX')

ans =

      20

the answer is as expected so it is not really clear what your problem is?

[Muhammad Usman Saleem]

@ Ingrid thanks for contributions.. Actually i have grader which will run and test whether my program makes sense or not? I have posted complete question above. Please read this and check whether i am doing correct or not?

Answer 3

[Tai Kieu]

Can you explain more about making the ouput uint8? I don't really quite understand about it.

[Walter Roberson]

double_7 = 7.0;
uint8_7 = uint8(double_7);