math: Improve comments.

[pspp] / src / math / np.h

diff --git a/src/math/np.h b/src/math/np.h
index 2fa009f90aa8b2a6465a0435adc356ac2e6d018b..998bee089e20fd66f83288fe4d42fb4de1ea8b9c 100644 (file)
--- a/src/math/np.h
+++ b/src/math/np.h
@@ -29,6 +29,8 @@ enum
     n_NP_IDX
   };
 
+/* Statistics needed to produce a normal probability plot with
+   np_plot_create(). */
 struct np
 {
   struct order_stats parent;