06.2026

2026-06-24 13:28:45 +02:00
parent b658ce0a15
commit 97ecbd2af2
113 changed files with 5193 additions and 456368 deletions
@@ -0,0 +1,89 @@
+package sparseviewer.interp;
+
+public class NearestInterpolator {
+
+    public static InterpolationResult interpolate(double[] x,
+                                                  double[] y,
+                                                  double[] z,
+                                                  int width,
+                                                  int height) {
+        Grid2D grid = createGrid(x, y, width, height);
+        float[] out = new float[width * height];
+
+        for (int iy = 0; iy < height; iy++) {
+            double gy = grid.yAt(iy);
+
+            for (int ix = 0; ix < width; ix++) {
+                double gx = grid.xAt(ix);
+
+                int best = -1;
+                double bestD2 = Double.POSITIVE_INFINITY;
+
+                for (int i = 0; i < x.length; i++) {
+                    if (!isFinite(x[i]) || !isFinite(y[i]) || !isFinite(z[i])) {
+                        continue;
+                    }
+
+                    double dx = x[i] - gx;
+                    double dy = y[i] - gy;
+                    double d2 = dx * dx + dy * dy;
+
+                    if (d2 < bestD2) {
+                        bestD2 = d2;
+                        best = i;
+                    }
+                }
+
+                if (best >= 0) {
+                    out[iy * width + ix] = (float) z[best];
+                } else {
+                    out[iy * width + ix] = Float.NaN;
+                }
+            }
+        }
+
+        return new InterpolationResult(grid, out);
+    }
+
+    private static Grid2D createGrid(double[] x, double[] y, int width, int height) {
+        double xmin = Double.POSITIVE_INFINITY;
+        double xmax = Double.NEGATIVE_INFINITY;
+        double ymin = Double.POSITIVE_INFINITY;
+        double ymax = Double.NEGATIVE_INFINITY;
+
+        for (int i = 0; i < x.length; i++) {
+            if (isFinite(x[i])) {
+                if (x[i] < xmin) xmin = x[i];
+                if (x[i] > xmax) xmax = x[i];
+            }
+
+            if (isFinite(y[i])) {
+                if (y[i] < ymin) ymin = y[i];
+                if (y[i] > ymax) ymax = y[i];
+            }
+        }
+
+        if (xmin == xmax) {
+            xmin -= 1.0;
+            xmax += 1.0;
+        }
+
+        if (ymin == ymax) {
+            ymin -= 1.0;
+            ymax += 1.0;
+        }
+
+        double xpad = 0.03 * (xmax - xmin);
+        double ypad = 0.03 * (ymax - ymin);
+
+        return new Grid2D(width, height,
+                xmin - xpad,
+                xmax + xpad,
+                ymin - ypad,
+                ymax + ypad);
+    }
+
+    private static boolean isFinite(double v) {
+        return !Double.isNaN(v) && !Double.isInfinite(v);
+    }
+}