  High $p_\perp$ theory and data are commonly used to study high $p_\perp$
parton interactions with QGP, while low $p_\perp$ data and corresponding models
are employed to infer QGP bulk properties. On the other hand, with a proper
description of high $p_\perp$ parton-medium interactions, high $p_\perp$ probes
become also powerful tomography tools, since they are sensitive to global QGP
features, such as different temperature profiles or initial conditions. This
tomographic role of high $p_\perp$ probes can be utilized to assess the spatial
anisotropy of the QCD matter. With our dynamical energy loss formalism, we show
that a (modified) ratio of $R_{AA}$ and $v_2$ presents a reliable and robust
observable for straightforward extraction of initial state anisotropy. We
analytically estimated the proportionality between the $v_2/(1-R_{AA})$ and
anisotropy coefficient $\epsilon_{2L}$, and found surprisingly good agreement
with full-fledged numerical calculations. Within the current error bars, the
extraction of the anisotropy from the existing data using this approach is
still inaccessible. However, with the expected accuracy improvement in the
upcoming LHC runs, the anisotropy of the QGP formed in heavy ion collisions can
be straightforwardly derived from the data. Such a data-based anisotropy
parameter would present an important test to models describing the initial
stages of heavy-ion collision and formation of QGP, and demonstrate the
usefulness of high $p_\perp$ theory and data in obtaining QGP properties.
