diff --git a/source/net/yacy/visualization/CircleTool.java b/source/net/yacy/visualization/CircleTool.java
index 153bccf60..3da15f086 100644
--- a/source/net/yacy/visualization/CircleTool.java
+++ b/source/net/yacy/visualization/CircleTool.java
@@ -62,15 +62,15 @@ public class CircleTool {
             r1 = (short) (r + 1);
             crc = new ArrayList<short[]>();
             for (short a = 0; a < 2 * (r + 1); a++) {
-                x = (short) (r1 * Math.cos(Math.PI * a / (4 * r1)));
-                y = (short) (r1 * Math.sin(Math.PI * a / (4 * r1)));
+                x = (short) (r1 * Math.cos(RasterPlotter.PI4 * a / r1));
+                y = (short) (r1 * Math.sin(RasterPlotter.PI4 * a / r1));
                 co = x + "|" + y;
                 if (!(crds.contains(co))) {
                     crc.add(new short[]{x, y});
                     crds.add(co);
                 }
-                x = (short) ((r + 0.5) * Math.cos(Math.PI * a / (4 * r1)));
-                y = (short) ((r + 0.5) * Math.sin(Math.PI * a / (4 * r1)));
+                x = (short) ((r + 0.5) * Math.cos(RasterPlotter.PI4 * a / r1));
+                y = (short) ((r + 0.5) * Math.sin(RasterPlotter.PI4 * a / r1));
                 co = x + "|" + y;
                 if (!(crds.contains(co))) {
                     crc.add(new short[]{x, y});
diff --git a/source/net/yacy/visualization/GraphPlotter.java b/source/net/yacy/visualization/GraphPlotter.java
index 5731bfc53..6db6eb919 100644
--- a/source/net/yacy/visualization/GraphPlotter.java
+++ b/source/net/yacy/visualization/GraphPlotter.java
@@ -103,9 +103,6 @@ public class GraphPlotter implements Cloneable {
         }
     }
 
-    private final static double p2 = Math.PI / 2.0;
-    private final static double p23 = p2 * 3.0;
-
     public static void force(Point calcPoint, Point currentPoint, Point otherPoint, Ribbon r) {
         double dx = otherPoint.x - currentPoint.x;
         double dy = otherPoint.y - currentPoint.y;
@@ -121,10 +118,10 @@ public class GraphPlotter implements Cloneable {
         assert !(!attraction && a < Math.PI) || y1 <= 0 : "attraction = " + attraction + ", a = " + a + ", y1 = " + y1;
         assert !(attraction && a > Math.PI) || y1 <= 0 : "attraction = " + attraction + ", a = " + a + ", y1 = " + y1;
         assert !(!attraction && a > Math.PI) || y1 >= 0 : "attraction = " + attraction + ", a = " + a + ", y1 = " + y1;
-        assert !(attraction && (a < p2 || a > p23)) || x1 >= 0  : "attraction = " + attraction + ", a = " + a + ", x1 = " + x1;
-        assert !(!attraction && (a < p2 || a > p23)) || x1 <= 0  : "attraction = " + attraction + ", a = " + a + ", x1 = " + x1;
-        assert !(attraction && !(a < p2 || a > p23)) || x1 <= 0  : "attraction = " + attraction + ", a = " + a + ", x1 = " + x1;
-        assert !(!attraction && !(a < p2 || a > p23)) || x1 >= 0  : "attraction = " + attraction + ", a = " + a + ", x1 = " + x1;
+        assert !(attraction && (a < RasterPlotter.PI2 || a > RasterPlotter.PI32)) || x1 >= 0  : "attraction = " + attraction + ", a = " + a + ", x1 = " + x1;
+        assert !(!attraction && (a < RasterPlotter.PI2 || a > RasterPlotter.PI32)) || x1 <= 0  : "attraction = " + attraction + ", a = " + a + ", x1 = " + x1;
+        assert !(attraction && !(a < RasterPlotter.PI2 || a > RasterPlotter.PI32)) || x1 <= 0  : "attraction = " + attraction + ", a = " + a + ", x1 = " + x1;
+        assert !(!attraction && !(a < RasterPlotter.PI2 || a > RasterPlotter.PI32)) || x1 >= 0  : "attraction = " + attraction + ", a = " + a + ", x1 = " + x1;
         calcPoint.x += x1;
         calcPoint.y += y1;
     }
diff --git a/source/net/yacy/visualization/RasterPlotter.java b/source/net/yacy/visualization/RasterPlotter.java
index 4f21f4d1e..1494c6a75 100644
--- a/source/net/yacy/visualization/RasterPlotter.java
+++ b/source/net/yacy/visualization/RasterPlotter.java
@@ -4,10 +4,6 @@
 //
 // This is a part of YaCy, a peer-to-peer based web search engine
 //
-// $LastChangedDate$
-// $LastChangedRevision$
-// $LastChangedBy$
-//
 // LICENSE
 //
 // This program is free software; you can redistribute it and/or modify
@@ -46,7 +42,6 @@ import java.awt.image.DataBufferByte;
 import java.awt.image.Raster;
 import java.awt.image.WritableRaster;
 import java.io.BufferedOutputStream;
-import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
@@ -66,6 +61,10 @@ public class RasterPlotter {
     public final Log log = new Log("RasterPlotter");
 
     public static final double PI180 = Math.PI / 180.0d;
+    public static final double PI4 = Math.PI / 4.0d;
+    public static final double PI2 = Math.PI / 2.0d;
+    public static final double PI32 = PI2 * 3.0d;
+    public static final double TL = Math.sqrt(3) / 2;
 
     // colors regarding RGB Color Model
     public static final long RED    = 0xFF0000;
@@ -380,9 +379,6 @@ public class RasterPlotter {
         line(x2, y2, xt, yt, 100); // left line
         line(x3, y3, xt, yt, 100); // right line
     }
-
-    private final static double TL = Math.sqrt(3) / 2;
-    private final static double PI2 = Math.PI / 2;
     
     public int[] getColor(final int x, final int y) {
         final int[] c = new int[3];
@@ -836,10 +832,9 @@ public class RasterPlotter {
         int i = 0;
         for (int row = 0; row < height; row++) {
             compBytes.write(0);
-            for (int column = 0; column < width; column++) {
-                compBytes.write(frame, i, 3); // this replaces the whole PixelGrabber process which makes it probably more than 800x faster. See http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4835595
-                i += 3;
-            }
+            // this replaces the whole PixelGrabber process which makes it probably more than 800x faster. See http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4835595
+            compBytes.write(frame, i, 3 * width);
+            i += 3 * width;
         }
         compBytes.close();