  We analyze non-central heavy-ion collisions at the relativistic energy within
a full (3+1) dimensional hydrodynamic model. First, the initial parameters in
the hydrodynamic model are chosen so that we reproduce the experimental data of
both the rapidity distribution and the slope of transverse mass distribution in
central Pb + Pb collisions at 158 $A$ GeV at the CERN SPS. We next study the
validity of the ansatz of wounded nucleon scaling for the initial condition of
the hydrodynamic model through analysis of the rapidity distribution of
negative pions in non-central collisions. Moreover, a simple Monte Carlo method
is introduced to exactly calculate the particle distribution from resonance
decays.
