--- a/flys-artifacts/ChangeLog	Thu Jun 23 13:42:47 2011 +0000
+++ b/flys-artifacts/ChangeLog	Thu Jun 23 15:50:44 2011 +0000
@@ -1,3 +1,9 @@
+2011-06-23  Sascha L. Teichmann <sascha.teichmann@intevation.de>
+
+	* src/main/java/de/intevation/flys/exports/ATWriter.java: New.
+	  Writer for AT files. New code because our data model differs
+	  from Desktop-FLYS. Needs testing.
+
 2011-06-23  Ingo Weinzierl <ingo@intevation.de>
 
 	  flys/issue157 (Diagramm: Ursprung berechnete Abflusskurve)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/exports/ATWriter.java	Thu Jun 23 15:50:44 2011 +0000
@@ -0,0 +1,149 @@
+package de.intevation.flys.exports;
+
+import java.io.IOException;
+import java.io.Writer;
+import java.io.PrintWriter;
+
+import java.util.Locale;
+
+import de.intevation.flys.artifacts.model.WQ;
+
+import org.apache.commons.math.analysis.interpolation.SplineInterpolator;
+
+import org.apache.commons.math.analysis.polynomials.PolynomialSplineFunction;
+
+import org.apache.commons.math.ArgumentOutsideDomainException;
+
+import org.apache.log4j.Logger;
+
+public class ATWriter
+{
+    private static Logger logger = Logger.getLogger(ATWriter.class);
+
+    public static final int COLUMNS = 10;
+
+    public static final String EMPTY = "             ";
+
+    protected double minW;
+    protected double maxW;
+    protected double minQ;
+    protected double maxQ;
+
+    protected PolynomialSplineFunction qFunc;
+
+    public ATWriter() {
+    }
+
+    public ATWriter(WQ wq) throws IllegalArgumentException {
+
+        int maxIndex = maxIncreasingWIndex(wq);
+
+        if (maxIndex < 1) { // Only first w can be written out.
+            minW = maxW = wq.getW(0);
+            minQ = maxQ = wq.getQ(0);
+            return;
+        }
+
+        double [] ws = new double[maxIndex+1];
+        double [] qs = new double[ws.length];
+
+        for (int i = 0; i < ws.length; ++i) {
+            ws[i] = wq.getW(i);
+            qs[i] = wq.getQ(i);
+        }
+
+        SplineInterpolator interpolator = new SplineInterpolator();
+
+        qFunc = interpolator.interpolate(ws, qs);
+
+        minW = wq.getW(0);
+        maxW = wq.getW(maxIndex);
+        minQ = wq.getQ(0);
+        maxQ = wq.getQ(maxIndex);
+    }
+
+    public static int maxIncreasingWIndex(WQ wq) {
+
+        int N = wq.size();
+
+        if (N < 2) {
+            return N-1;
+        }
+
+        double last = wq.getW(0);
+
+        for (int i = 1; i < N; ++i) {
+            double current = wq.getW(i);
+            if (current <= last) {
+                return i-1;
+            }
+        }
+
+        return N-1;
+    }
+
+    public double getQ(double w) {
+
+        try {
+            return qFunc.value(w);
+        }
+        catch (ArgumentOutsideDomainException aode) {
+            // should not happen
+            logger.warn("spline interpolation failed", aode);
+            return w <= minW ? minQ : maxQ;
+        }
+    }
+
+    protected static void printQ(PrintWriter out, double q) {
+        String format;
+             if (q <   1) format = " % 8.3f";
+        else if (q <  10) format = " % 8.2f";
+        else if (q < 100) format = " % 8.1f";
+        else {
+            format = " % 8.0f";
+            if (q > 1000) q = Math.rint(q/10)*10;
+        }
+        out.printf(Locale.US, format, q);
+    }
+
+    public void write(Writer writer) throws IOException {
+
+        PrintWriter out = new PrintWriter(writer);
+
+        double range = COLUMNS;
+
+        double rest = Math.abs(minW % range);
+
+        int startW = (int)(minW - rest);
+        if (rest >= 1d) {
+            out.printf(Locale.US, "%8d", startW);
+            int columns = (int)Math.floor(rest);
+            for (int i = columns; i < COLUMNS; ++i) {
+                out.print(EMPTY);
+            }
+            for (int i = 0, N = COLUMNS-columns; i < N; ++i) {
+                printQ(out, getQ(startW + (COLUMNS-i-1)));
+            }
+            startW += COLUMNS;
+        }
+
+        int col = 0;
+        for (int w = startW; w <= maxW; ++w) {
+            if (col == 0) out.printf(Locale.US, "%8d", w);
+
+            printQ(out, getQ(w));
+
+            if (++col >= COLUMNS) {
+                out.println();
+                col = 0;
+            }
+        }
+
+        if (col > 0) {
+            out.println();
+        }
+
+        out.flush();
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :