示例#1
0
        /// <summary>
        ///     Fit the input x,y points using a 'geometric' strategy so that y does not have to be a single-valued
        ///     function of x.
        /// </summary>
        /// <param name="x">Input x coordinates.</param>
        /// <param name="y">Input y coordinates, do not need to be a single-valued function of x.</param>
        /// <param name="nOutputPoints">How many output points to create.</param>
        /// <param name="xs">Output (interpolated) x values.</param>
        /// <param name="ys">Output (interpolated) y values.</param>
        public static void FitGeometric(float[] x, float[] y, int nOutputPoints, out float[] xs, out float[] ys)
        {
            // Compute distances
            var n     = x.Length;
            var dists = new float[n]; // cumulative distance

            dists[0] = 0;
            float totalDist = 0;

            for (var i = 1; i < n; i++)
            {
                var dx   = x[i] - x[i - 1];
                var dy   = y[i] - y[i - 1];
                var dist = (float)Math.Sqrt(dx * dx + dy * dy);
                totalDist += dist;
                dists[i]   = totalDist;
            }

            // Create 'times' to interpolate to
            var dt    = totalDist / (nOutputPoints - 1);
            var times = new float[nOutputPoints];

            times[0] = 0;

            for (var i = 1; i < nOutputPoints; i++)
            {
                times[i] = times[i - 1] + dt;
            }

            // Spline fit both x and y to times
            var xSpline = new CubicSplineInterpolator();

            xs = xSpline.FitAndEval(dists, x, times);

            var ySpline = new CubicSplineInterpolator();

            ys = ySpline.FitAndEval(dists, y, times);
        }
示例#2
0
        /// <summary>
        ///     Static all-in-one method to fit the splines and evaluate at X coordinates.
        /// </summary>
        /// <param name="x">Input. X coordinates to fit.</param>
        /// <param name="y">Input. Y coordinates to fit.</param>
        /// <param name="xs">Input. X coordinates to evaluate the fitted curve at.</param>
        /// <param name="startSlope">Optional slope constraint for the first point. Single.NaN means no constraint.</param>
        /// <param name="endSlope">Optional slope constraint for the final point. Single.NaN means no constraint.</param>
        /// <param name="debug">Turn on console output. Default is false.</param>
        /// <returns>The computed y values for each xs.</returns>
        public static float[] Compute(float[] x, float[] y, float[] xs, float startSlope = float.NaN, float endSlope = float.NaN, bool debug = false)
        {
            var spline = new CubicSplineInterpolator();

            return(spline.FitAndEval(x, y, xs, startSlope, endSlope, debug));
        }