  Measurements of anisotropic flow Fourier coefficients ($v_n$) for inclusive
charged particles and identified hadrons $\pi^{\pm}$, $K^{\pm}$, $p$, and
$\bar{p}$ produced at midrapidity in Cu+Au collisions at $\sqrt{s_{_{NN}}}=200$
GeV are presented. The data were collected in 2012 by the PHENIX experiment at
the Relativistic Heavy Ion Collider (RHIC). The particle azimuthal
distributions with respect to different order symmetry planes $\Psi_n$, for
$n$~=~1, 2, and 3 are studied as a function of transverse momentum $p_T$ over a
broad range of collisions centralities. Mass ordering, as expected from
hydrodynamic flow, is observed for all three harmonics. The charged-particle
results are compared to hydrodynamical and transport model calculations. We
also compare these Cu$+$Au results with those in Cu$+$Cu and Au$+$Au collisions
at the same $\sqrt{s_{_{NN}}}$, and find that the $v_2$ and $v_3$, as a
function of transverse momentum, follow a common scaling with $1/(\varepsilon_n
N_{\rm part}^{1/3})$.
