how convert fraction into integer?

hi, how convert fraction part into integer :

30.6789 to 6789

thanks

[huda nawaf]

i want add something

when i get 6789 for ex.

i want change it into 6790 for ex.

and return this no. into fraction such as: 30.6790

thanks

[Walter Roberson]

Why not just add .0001 ?

Answer 1

[Jonathan Sullivan]

Looks like you want to round to the nearest 0.001. You can do this with the following:

x = 30.6789 % Or whatever your data is
base = 0.001; % Or whatever you are rounding too.
x_rounded = round(x./base).*base;

Hope this helps!

[huda nawaf]

thanks,

but i need isolate the integer from fraction , then i can change the fraction as i need.

i need get the fraction part whatever it, i do not know it and do not know it's lengths.

i need the fraction part alone , then may hide in it bits then return it as fraction after modify it

[Walter Roberson]

The fraction you are looking for would have to be in base 10, but in base 10 it would be inappropriate to work at the *bit* level; instead you would have to work at the *dit* level (though the proper name for a "dit" is a "ban"; http://en.wikipedia.org/wiki/Ban_%28information%29)

Mixing base 10 and base 2 needs to be done very carefully!

Answer 2

[Image Analyst]

How about this:

a=30.6789;
out = (a - floor(a)) * 10000

You do need the base, for example 10000. Why? Because the fraction never ends as I'm sure you know because you've read the FAQ. Want proof? Check this out:

format long;
a  % Display it.  It won't be 30.6789!

>> a =
  30.678899999999999

So that's why you have to pick some number of decimal places.

[Walter Roberson]

For the benefit of those who might not have read the referenced FAQ,

http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F