A question on reading data from a file

Hi everyone,

I know this is basic, yet I would like to know the reason why this happens.

I'm playing with fortran doing the standard, suppose I have a initial condition between [0:2pi]

with a chaoticity parameter K=1.0. If I want to repeat the experiment numerically I read from

a file the initial condition that I use in the first experiment. I check the results by looking at it

and I notice that although I read and start with the same number (e.g. 0.475265000237136  2.58735041435918)

after 3 or 5 steps of applying the map over this initial conditions I see differences in the numerical results.

This obviously says that there's something different between the data read from a file and the data that one

creates to to calculations on the fly. Why is that?

Thanks,

Adrian