+
+\f
+/*
+ Returns zero, if W is a missing value for WV or if it is less than zero.
+ Typically used to force a numerical value into a valid weight.
+
+ As a side effect, this function will emit a warning if the value
+ WARN_ON_INVALID points to a bool which is TRUE. That bool will be then
+ set to FALSE.
+ */
+double
+var_force_valid_weight (const struct variable *wv, double w, bool *warn_on_invalid)
+{
+ if (w < 0.0 || (wv && var_is_num_missing (wv, w, MV_ANY)))
+ w = 0.0;
+
+ if (w == 0.0 && warn_on_invalid != NULL && *warn_on_invalid)
+ {
+ *warn_on_invalid = false;
+ msg (SW, _("At least one case in the data file had a weight value "
+ "that was user-missing, system-missing, zero, or "
+ "negative. These case(s) were ignored."));
+ }
+
+ return w;
+}