  A stochastic gravitational-wave background (SGWB) is expected from the
superposition of a wide variety of independent and unresolved astrophysical and
cosmological sources from different stages in the evolution of the Universe.
Radiometric techniques are used to make sky maps of anisotropies in the SGWB by
cross-correlating data from pairs of detectors. The conventional searches can
be made hundreds of times faster through the folding mechanism introduced
recently. Here we present a newly developed algorithm to perform the SGWB
searches in a highly efficient way. Taking advantage of the compactness of the
folded data we replaced the loops in the pipeline with matrix multiplications.
We also incorporated well-known HEALPix pixelization tools for further
standardization and optimization. Our Python-based implementation of the
algorithm is available as an open source package ${\tt PyStoch}$. Folding and
${\tt PyStoch}$ together has made the radiometer analysis $\textit{a few
thousand times}$ faster; it is now possible to make all-sky maps of a
stochastic background in just a few minutes on an ordinary laptop. Moreover,
${\tt PyStoch}$ generates a skymap at every frequency bin as an intermediate
data product. These techniques have turned SGWB searches very convenient and
will make computationally challenging analyses like blind all-sky narrowband
search feasible.
