Guards against two behaviors of QCA::truthTable() (observed with
QCA 3.25 / admisc 0.40) that can affect programmatic, repeated calls such
as threshold sweeps. For sparse truth tables the incl/PRI
columns may be returned as character rather than numeric,
and logical-remainder rows (observed n = 0) may carry the string
"-". Passing such a truth table to QCA::minimize() can, for
some truth table structures, cause the minimization to hang or return
misleading fit values. This helper coerces incl/PRI to
numeric and sets the remainder rows to 0.
sanitize_truthtable(tt)A truth table object returned by QCA::truthTable().
The same object with numeric incl/PRI columns and
no NA in those columns. Returns the input unchanged if it is
NULL or lacks a $tt data frame.
The OUT column is deliberately left untouched: minimize()
uses OUT (with the symbolic "?" for remainders) to identify
positive, negative, and remainder rows, so setting incl/PRI
to 0 on remainder rows does not alter remainder handling.