Weird answer for function when dividing two fractions

function c = c_div(r, s)  % Divides vectors 
 
  % Compute c = r / s, where r, s and c are rational numbers defined as 
  % 2-vectors
 
  c(1) = r(1) * s(2); % numerator
  c(2) = r(2) * s(1); % denominator
  
  c = c / gcd(c(1), c(2)); % using gcd to leave the c in its simplest form
  
end

I want to divide:

r = [4501700 1000] 
s = [128 202042]

So I use myc_div(r, s) and the answer is:

ans =
   1.0e+09 *
   4.547662357000000   0.000000640000000

What does this mean as the answer should be 7105722.433

Answer 1

[Robert U]

Hi Katy Soto,

type the following to command line to prevent Matlab from shortening output:

format long g

Then output of your function is

c_div(r, s)

ans =

                4547662357                       640
                

This is the rational number in the same format as the input.

ans(1)/ans(2)

ans =

           7105722.4328125

Kind regards,

Robert

[Katy Soto]

Thank you!