diff --git a/src/bin/flat/riemann.rs b/src/bin/flat/riemann.rs
index 2acbe50..fea378d 100644
--- a/src/bin/flat/riemann.rs
+++ b/src/bin/flat/riemann.rs
@@ -156,6 +156,7 @@ pub mod samples {
 	use super::{Decomp2, Metric};
 
 	pub struct ScaledMetric {
+		/// Specifies unit size in each cardinal direction. E.g. with scale=(2, 3), vector (1, 0) has length 2 while a unit vector with the same direction is (1/2, 0).
 		pub scale: Vec2,
 	}