Index: /trunk/psLib/src/math/psSpline.c
===================================================================
--- /trunk/psLib/src/math/psSpline.c	(revision 42822)
+++ /trunk/psLib/src/math/psSpline.c	(revision 42823)
@@ -194,8 +194,8 @@
  *****************************************************************************/
 psSpline1D *psSpline1DFitVector(
-    const psVector* x,                  ///< Ordinates.
-    const psVector* y,                  ///< Coordinates.
-    psF32 dyLower,			///< 1st derivative at lower bound
-    psF32 dyUpper)			///< 1st derivative at upper bound
+    const psVector* x,	      ///< Ordinates.
+    const psVector* y,	      ///< Coordinates.
+    psF32 dyLower,	      ///< if not NAN, lower-bound 1st derivative is defined
+    psF32 dyUpper)	      ///< if not NAN, lower-bound 1st derivative is defined
 {
     psTrace("psLib.math", 3, "---- %s() begin ----\n", __func__);
Index: /trunk/psLib/src/math/psSpline.h
===================================================================
--- /trunk/psLib/src/math/psSpline.h	(revision 42822)
+++ /trunk/psLib/src/math/psSpline.h	(revision 42823)
@@ -36,11 +36,11 @@
 {
     unsigned int n;    ///< The number of knots
-    psF32 *xKnots; ///< x-coordinate of the knots
-    psF32 *yKnots; ///< y-coordinate of the knots
-    psF32 *d2yKnots; ///< 2nd derivative of y at the knots
-    bool equalSpacing; // if knots are equally spaced, the seqment choice can be optimized
-    psF32 xMin; // for equally-spaced knots, the value at the lower bound (xKnots[0])
-    psF32 xMax; // for equally-spaced knots, the value at the upper bound (xKnots[n])
-    psF32 xDel; // for equally-spaced knots, the spacing (xKnots[n] - xKnots[0])/n
+    psF32 *xKnots;     ///< x-coordinate of the knots
+    psF32 *yKnots;     ///< y-coordinate of the knots
+    psF32 *d2yKnots;   ///< 2nd derivative of y at the knots
+    bool equalSpacing; ///< if knots are equally spaced, the seqment choice can be optimized
+    psF32 xMin;	       ///< for equally-spaced knots, the value at the lower bound (xKnots[0])
+    psF32 xMax;	       ///< for equally-spaced knots, the value at the upper bound (xKnots[n])
+    psF32 xDel;	       ///< for equally-spaced knots, the spacing (xKnots[n] - xKnots[0])/n
 }
 psSpline1D;