diff --git a/src/data_plot.h b/src/data_plot.h
new file mode 100644
--- /dev/null
+++ b/src/data_plot.h
@@ -0,0 +1,86 @@
+/*
+ *
+ *  $Id$
+ *
+ *  This file is part of the Virtual Leaf.
+ *
+ *  The Virtual Leaf is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The Virtual Leaf is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with the Virtual Leaf.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *  Copyright 2010 Roeland Merks.
+ *
+ */
+
+#ifndef _DATA_PLOT_H_
+#define _DATA_PLOT_H_
+
+#include <QDialog>
+#include <qwt_plot.h>
+#include <iostream>
+#include <QFile>
+#include <QTextStream>
+#include <qwt_plot_curve.h>
+#include "curvecolors.h"
+
+const int PLOT_SIZE = 1000; 
+
+class DataPlot : public QwtPlot
+{
+    Q_OBJECT
+
+public:
+  DataPlot(QWidget *parent, const QString title, const QStringList curvenames);
+  virtual ~DataPlot(void);
+public slots:
+    //    void setTimerInterval(double interval);
+    void AddValue(double t, double *x);
+
+private:
+    void alignScales();
+
+    double *d_t; 
+    double **d_x; 
+
+    int d_interval; // timer in ms
+    int d_timerId;
+    
+    QwtPlotCurve *curves;
+    int data_pos;
+    int ncurves;
+    
+    CurveColors curvecolors;
+
+ protected:
+    // to write contents of DataPlot to a file
+    QFile *datfile;
+    QTextStream datstream;
+
+};
+
+class PlotDialog : public QDialog {
+
+Q_OBJECT
+ public:
+  PlotDialog(QWidget *parent, const QString title, const QStringList curvenames);
+  ~PlotDialog(void);
+  public slots:
+    //    void setTimerInterval(double interval);
+  void AddValue(double t, double *x) {
+    //std::cerr << "AddValue receives: " << t << ", " << y << ", " << z << std::endl;
+    plot->AddValue(t,x);
+  }
+ private:
+  DataPlot *plot;
+};
+
+#endif