1 files changed, 3 insertions, 0 deletions
diff --git a/src/mathfunc.h b/src/mathfunc.h
index 42e76e5..0d791a1 100644
--- a/src/mathfunc.h
+++ b/src/mathfunc.h
@@ -28,6 +28,9 @@
 
 using namespace std;
 
+inline bool is_nan(double f) {
+  return (std::isnan(f));
+}
 
 bool has_nan(const vector<double> v);
 bool has_nan(const gsl_vector *v);