--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/model/WstValueTable.java	Fri Feb 17 11:29:41 2012 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/model/WstValueTable.java	Fri Feb 17 12:59:56 2012 +0000
@@ -496,6 +496,28 @@
 
             return qs.toNativeArray();
         }
+
+        public double [] getMinMaxW(double [] result) {
+            double minW =  Double.MAX_VALUE;
+            double maxW = -Double.MAX_VALUE;
+            for (int i = 0; i < ws.length; ++i) {
+                double w = ws[i];
+                if (w < minW) minW = w;
+                if (w > maxW) maxW = w;
+            }
+            result[0] = minW;
+            result[1] = maxW;
+            return result;
+        }
+
+        public double [] getMinMaxW(Row other, double km, double [] result) {
+            double [] m1 = this .getMinMaxW(new double [2]);
+            double [] m2 = other.getMinMaxW(new double [2]);
+            double factor = Linear.factor(km, this.km, other.km);
+            result[0] = Linear.weight(factor, m1[0], m2[0]);
+            result[1] = Linear.weight(factor, m1[1], m2[1]);
+            return result;
+        }
     } // class Row
 
     /** Rows in table. */
@@ -585,6 +607,64 @@
         return ws;
     }
 
+    public double [] getMinMaxW(double km) {
+        return getMinMaxW(km, new double [2]);
+
+    }
+    public double [] getMinMaxW(double km, double [] result) {
+        int rowIndex = Collections.binarySearch(rows, new Row(km));
+
+        if (rowIndex >= 0) {
+            return rows.get(rowIndex).getMinMaxW(result);
+        }
+
+        rowIndex = -rowIndex -1;
+
+        if (rowIndex < 1 || rowIndex >= rows.size()) {
+            // do not extrapolate
+            return null;
+        }
+
+        Row r1 = rows.get(rowIndex-1);
+        Row r2 = rows.get(rowIndex);
+
+        return r1.getMinMaxW(r2, km, result);
+    }
+
+    public double [] getMinMaxW(double from, double to, double step) {
+        double [] result = new double[2];
+
+        double minW =  Double.MAX_VALUE;
+        double maxW = -Double.MAX_VALUE;
+
+        if (from > to) {
+            double tmp = from;
+            from = to;
+            to = tmp;
+        }
+
+        step = Math.max(Math.abs(step), 0.0001);
+
+        double d = from;
+        for (; d <= to; d += step) {
+            if (getMinMaxW(d, result) != null) {
+                if (result[0] < minW) minW = result[0];
+                if (result[1] > maxW) maxW = result[1];
+            }
+        }
+
+        if (d != to) {
+            if (getMinMaxW(to, result) != null) {
+                if (result[0] < minW) minW = result[0];
+                if (result[1] > maxW) maxW = result[1];
+            }
+        }
+
+        return minW < Double.MAX_VALUE
+            ? new double [] { minW, maxW }
+            : null;
+    }
+
     /**
      * Interpolate W and Q values at a given km.
      */