+/*
+PSPP - a program for statistical analysis.
+Copyright (C) 2017 Free Software Foundation, Inc.
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
#ifndef EXPRESSIONS_HELPERS_H
#define EXPRESSIONS_HELPERS_H
double idf_fdist (double P, double a, double b);
+double round_nearest (double x, double mult, double fuzzbits);
+double round_zero (double x, double mult, double fuzzbits);
+
+struct substring replace_string (struct expression *,
+ struct substring haystack,
+ struct substring needle,
+ struct substring replacement,
+ double n);
+
+double median (double *, size_t n);
+
#endif /* expressions/helpers.h */