can I convert a decimal number into rational number in matlab and how can i write a factorial of large number like 30 completely i.e. in complete integral from instead of decimal form

can I convert a decimal number into rational number in matlab. How can I write a factorial of large number like 30 completely i.e. in complete integral from instead of decimal form.

Answer 1

[Stephen23]

Try using rat or rats:

>> [N,D] = rat(0.8)
N =
     4
D =
     5
>> rats(0.8)
ans =
      4/5

Answer 2

[Star Strider]

To get the full numeric precision for ‘factorial(30)’, you would need the Symbolic Math Toolbox (although I believe John D’Errico has a File Exchange contribution that will provide the same results).

Example:

fd = factorial(30)                                              % Double-Precision Representation
fs = vpa(factorial(30), 40)                                     % Symbolic Math Toolbox ‘vpa’ Representation

fd =
      2.65252859812191e+32

fs =
265252859812191032188804700045312.0

[Walter Roberson]

You need factorial(sym(30))