interpolation: additional constructors

Signed-off-by: Christoph Ruegg <git@cdrnet.ch>

src/Numerics/Interpolation/Algorithms/CubicSplineInterpolation.cs

@@ -63,7 +63,38 @@ namespace MathNet.Numerics.Interpolation.Algorithms
             IList<double> sampleValues)
         {
             _spline = new CubicHermiteSplineInterpolation();
-            Initialize(samplePoints, sampleValues);
+
+            Initialize(
+                samplePoints,
+                sampleValues);
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the CubicSplineInterpolation class.
+        /// </summary>
+        /// <param name="samplePoints">Sample Points t, sorted ascending.</param>
+        /// <param name="sampleValues">Sample Values x(t)</param>
+        /// <param name="leftBoundaryCondition">Condition of the left boundary.</param>
+        /// <param name="leftBoundary">Left boundary value. Ignored in the parabolic case.</param>
+        /// <param name="rightBoundaryCondition">Condition of the right boundary.</param>
+        /// <param name="rightBoundary">Right boundary value. Ignored in the parabolic case.</param>
+        public CubicSplineInterpolation(
+            IList<double> samplePoints,
+            IList<double> sampleValues,
+            SplineBoundaryCondition leftBoundaryCondition,
+            double leftBoundary,
+            SplineBoundaryCondition rightBoundaryCondition,
+            double rightBoundary)
+        {
+            _spline = new CubicHermiteSplineInterpolation();
+
+            Initialize(
+                samplePoints,
+                sampleValues,
+                leftBoundaryCondition,
+                leftBoundary,
+                rightBoundaryCondition,
+                rightBoundary);
         }
 
         /// <summary>

src/Numerics/Interpolation/Algorithms/FloaterHormannRationalInterpolation.cs

@@ -65,6 +65,24 @@ namespace MathNet.Numerics.Interpolation.Algorithms
             Initialize(samplePoints, sampleValues);
         }
 
+        /// <summary>
+        /// Initializes a new instance of the FloaterHormannRationalInterpolation class.
+        /// </summary>
+        /// <param name="samplePoints">Sample Points t</param>
+        /// <param name="sampleValues">Sample Values x(t)</param>
+        /// <param name="order">
+        /// Order of the interpolation scheme, 0 &lt;= order &lt;= N.
+        /// In most cases a value between 3 and 8 gives good results.
+        /// </param>
+        public FloaterHormannRationalInterpolation(
+            IList<double> samplePoints,
+            IList<double> sampleValues,
+            int order)
+        {
+            _barycentric = new BarycentricInterpolation();
+            Initialize(samplePoints, sampleValues, order);
+        }
+
         /// <summary>
         /// Gets a value indicating whether the algorithm supports differentiation (interpolated derivative).
         /// </summary>