  In the context of the longitudinally boost-invariant Bjorken flow with
transverse expansion, we use three different numerical methods to analyze the
emergence of the attractor solution in an ideal gas of massless particles
exhibiting constant shear viscosity to entropy density ({\eta}/s) ratio. The
fluid energy density is initialized using a Gaussian profile in the transverse
plane, while the ratio \chi = P_L / P_T between the longitudinal and transverse
pressures is set at initial time to a constant value \chi_0 throughout the
system using the Romatschke-Strickland distribution. We highlight the
transition between the regimes where the longitudinal and transverse expansions
dominate. We find that the hydrodynamization time required for the attractor
solution to be reached increases with the distance from the origin, as expected
based on the properties of the 0+1D system defined by the local initial
conditions. We argue that hydrodynamization is predominantly the effect of the
longitudinal expansion, being significantly influenced by the transverse
dynamics only for small systems or for large values of {\eta}/s.
