You have to be using a random number seed. It's part of ECJ's parameters. I would check to see if it is set to a specific number.  You can see what the parameter values you're using are by running with -p print-params=true


On Jan 26, 2016, at 11:31 PM, bijoy patwal <[log in to unmask]> wrote:

> hi,
> thanks for the reply.
> I am not using random number seed.All the inputs are initialized.
> On Sat, Jan 23, 2016 at 4:01 AM, Sean Luke <[log in to unmask]> wrote:
> On Jan 22, 2016, at 1:32 AM, bijoy patwal <[log in to unmask]> wrote:
> > I am always getting the same fitness for every evolution though .
> Are you using the same random number seed?
> Try
>         seed.0 = time
> Sean