  We present a systematic study of the effects due to initial condition
fluctuations in systems formed by heavy-ion collisions using the hydrodynamical
simulation code NeXSPheRIO. The study was based on a sample of events generated
simulating Au+Au collisions at center of mass energy of 200 GeV per nucleon
pair with impact parameter ranging from most central to peripheral collisions.
The capability of the NeXSPheRIO code to control and save the initial condition
(IC) as well as the final state particles after the 3D hydrodynamical evolution
allows for the investigation of the sensitivity of the experimental observables
to the characteristics of the early IC. Comparisons of results from simulated
events generated using fluctuating initial conditions and smooth initial
condition are presented for the experimental observable elliptic flow parameter
($v_2$) as a function of the transverse momentum, $p_t$, and centrality. We
compare $v_2$ values estimated using different methods, and how each method
responds to effects of fluctuations in the initial condition. Finally, we
quantify the flow fluctuations and compare to the fluctuations of the initial
eccentricity of the energy density distribution in the transverse plane.
