  We report the direct -- continuous in phase -- sampling of a regularized $P$
function, the so-called nonclassicality quasiprobability, for squeezed light.
Through their negativities, the resulting phase-space representation uncovers
the quantum character of the state. In contrast to discrete phase-locked
measurements, our approach allows an unconditional verification of
nonclassicality by getting rid of interpolation errors due to fixed phases. To
realize the equal phase distribution of measured quadratures, a data selection
is implemented with quantum random numbers created by measuring the vacuum
noise. The continuously measured squeezed field was generated in an optical
parametric amplifier. Suitable pattern functions for obtaining the regularized
$P$ function are investigated. The significance of detecting negativities in
our application is determined. The sampling of nonclassicality
quasiprobabilities is shown to be a powerful and universal method to visualize
quantum effects within arbitrary quantum states.
