[P] _ms_build_info -- Building extra factor-variables information into
_ms_build_info matrix_name [if] [in] [weight] [, row elabels]
_ms_build_info builds some factor-variables information from the dataset
and stores it with the column stripe for matrix_name. This information
identifies empty cells in factors and interactions in the column stripe.
row specifies that the information come from the row stripe. The default
is the column stripe.
elabels specifies that value labels attached to factor variables in the
column stripe of matrix_name be copied into the current estimation
This option, when combined with row, makes the value labels available
for better labeled output when matrix_name is used with
_matrix_table; see _matrix_table.
_ms_build_info stores its results directly in the stripe information
associated with matrix_name.
With option elabels, _ms_build_info also invisibly adds value-label
information to the current estimation results.