How to transform years into centuries

Hey guys. I need to creat a function that transforms years in to centuries. I suppose i can do it with 30 if statements, but was wandering how we can do it in a smarter way.

Write a function called centuries that takes a positive integer smaller than or equal to 3000 representing a year as its input and returns a char vector with the century the given year falls into. If the input is invalid, the function returns the empty char vector '' (there is no space between the apostrophes). Centuries are specified using roman numerals. Note that we require the shortest legal roman number. For a complete list, refer to: http://www.romannumerals.co/roman-numerals-1-to-30. Note that a century goes from year 1 to 100, so for example, the XXth century ended on December 31st, 2000. As an example, the call

>> cent = centuries(1864);

will make cent equal to ‘XIX’.

[Radoslav Gagov]

This is my solution for now:

 function cent = centuries(a)
    if  ~isscalar(a) || a<1 || a >3000 || a ~= fix(a)
        cent = '';
    else
       rest = mod(a,100);
       c = floor(a/100);
       if rest ~= 0
         c = c+1;
       end
       b = {'I','II','III','IV','V','VI','VII','VIII','IX','X','XI','XII','XIII','XIV','XV','XVI','XVII','XVIII','XIX','XX','XXI','XXII','XXIII','XXIV','XXV','XXVI','XXVII','XXVIII','XXIX','XXX'} ;
       cent = b{c};
    end

[Guillaume]

If it works then you should submit it. It may be possible to make the conversion to roman numeral more generic but for the purpose of the assignment it's certainly good enough.

The only thing I'd change is to give meaningful names to all the variable.

[Guillermo Varela Carbajal]

Better to use ceil instead of floor

function cent = centuries (year)
 if  ~isscalar(year) || year<1 || year>3000 || year~=fix(year)
    cent = '';
 else
    roman = {'I','II','III','IV','V','VI','VII','VIII','IX','X','XI','XII','XIII','XIV','XV','XVI','XVII','XVIII','XIX','XX','XXI','XXII','XXIII','XXIV','XXV','XXVI','XXVII','XXVIII','XXIX','XXX'};
    cent = roman{ceil(year/100)};
 end

Answer 1

[RAMAKANT SHAKYA]

function s= centuries(n)
p={'I','II','III','IV','V','VI','VII','VIII','IX','X','XI','XII','XIII','XIV','XV','XVI','XVII',' XVIII','XIX','XX','XXI','XXII','XXIII','XXIV','XXV','XXVI','XXVII','XXVIII','XXIX','XXX'};
d=length(n);
if d>1
    n=-1;
end
if n>0&&n<=100&&n==fix(n)
    s='I';  %for less than 100
elseif n>100&&n<=3000 && n==fix(n)
    m=n/100;
    r=ceil(m);
    s=p{r};
else
    s='';
end
end