  We find the nine bulk--flow and shear moments from the SFI++ survey, as well
as for subsamples of group and field galaxies. We constrain the velocity power
spectrum shape parameter $\Gamma$ in linear theory using these moments. A
likelihood function for $\Gamma$ was found after marginalizing over the power
spectrum amplitude $\sigma_8\Omega_m^{0.6}$ using constraints obtained from
comparisons between redshift surveys and peculiar velocity data. We have
estimated the velocity noise $\sigma_*$ from the data since without it our
results may be biased. We also performed a statistical analysis of the
difference between the field and group catalogues and found that the results
from each reflect the same underlying large scale flows. We found that we can
constrain the power spectrum shape parameter to be
$\Gamma=0.15^{+0.18}_{-0.08}$ for the groups catalogue and
$\Gamma=0.09^{+0.04}_{-0.04}$ for the field galaxy catalogue in fair agreement
with the value from WMAP.
