diff --git a/src/main/java/info/istlab/Zemi01/numeric/NormalDistribution.java b/src/main/java/info/istlab/Zemi01/numeric/NormalDistribution.java
index d7638e9..b4649e6 100644
--- a/src/main/java/info/istlab/Zemi01/numeric/NormalDistribution.java
+++ b/src/main/java/info/istlab/Zemi01/numeric/NormalDistribution.java
@@ -69,7 +69,7 @@
 		double d1 = 1.0 / Math.sqrt(2 * Math.PI * xvarp);
 		double d2 = Math.exp(-Math.pow(x - xavg, 2) / (2 * xvarp));
 		double ret = d1 * d2 * 10000;
-		System.out.println(ret);
+		// System.out.println(ret);
 		return ret;
 	}
 
@@ -87,7 +87,7 @@
 		xavg = Ttest.avg(dat);
 		// 標準偏差を更新する
 		xvarp = Ttest.varp(dat);
-		System.out.println("μ " + xavg + "  σ^2 " + xvarp);
+		// System.out.println("μ " + xavg + "  σ^2 " + xvarp);
 
 	}
 
diff --git a/src/main/java/info/istlab/Zemi01/numeric/WelchTtest.java b/src/main/java/info/istlab/Zemi01/numeric/WelchTtest.java
new file mode 100644
index 0000000..02cb95d
--- /dev/null
+++ b/src/main/java/info/istlab/Zemi01/numeric/WelchTtest.java
@@ -0,0 +1,415 @@
+package info.istlab.Zemi01.numeric;
+
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.RenderingHints;
+import java.awt.event.KeyEvent;
+import java.awt.event.KeyListener;
+import java.awt.event.MouseEvent;
+import java.awt.event.MouseListener;
+import java.awt.event.MouseMotionListener;
+import java.awt.geom.Point2D;
+import java.util.ArrayList;
+import java.util.Random;
+
+import javax.swing.JFrame;
+import javax.swing.JPanel;
+
+import info.istlab.Zemi01.Launcher;
+import info.istlab.Zemi01.miuramath.Ttest;
+
+/**
+ * 正規分布、ガウス分布
+ */
+
+public class WelchTtest extends JPanel implements MouseListener, MouseMotionListener, KeyListener {
+
+	private static final long serialVersionUID = -919448575666487391L;
+	public static JFrame jf;
+
+	/**
+	 * @param args
+	 */
+	public static void main(String[] args) {
+		jf = new JFrame("正規分布、ガウス分布");
+		jf.getContentPane().add(new WelchTtest());
+		jf.pack();
+		jf.setVisible(true);
+		jf.setLocation(Launcher.centerOfScreen(jf.getSize()));
+
+		jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+		System.out.println("正規分布、ガウス分布 ");
+		System.out.println("つかいかた：(1)右クリックで、点を追加 (2)左ドラッグで、点移動 or グラフ移動 (3) 点の上で右クリックすると、点が消えます。");
+	}
+
+	Point2D offset;
+
+	ND[] normdist = new ND[2];
+	Dimension dim;
+	Point2D pointingPmath;
+	Point2D pressP;
+	static int psize = 10;
+
+	public Dimension getPreferredSize() {
+		return dim;
+	}
+
+	public WelchTtest() {
+		offset = new Point2D.Double(0, 100);
+
+		dim = new Dimension(500, 400);
+		addMouseListener(this);
+		addMouseMotionListener(this);
+		addKeyListener(this);
+		this.setFocusable(true);
+		this.requestFocusInWindow();
+
+		normdist[0] = new ND(Color.blue, 0, 0);
+		normdist[1] = new ND(Color.green, 20, -30);
+
+		setBackground(Color.white);
+		setForeground(Color.black);
+
+		updateNormDist();
+
+	}
+
+	public void paint(Graphics g) {
+		paintComponent(g);
+	}
+
+	public void paintComponent(Graphics g) {
+		Graphics2D g2d = (Graphics2D) g;
+		RenderingHints rh = new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+		g2d.setRenderingHints(rh);
+
+		// g2d.setBackground(Color.white);
+		// g2d.setColor(Color.black);
+		g2d.clearRect(0, 0, getWidth(), getHeight());
+
+		paintGrid(g2d);
+
+		if (pointingPmath != null) {
+			g2d.setColor(Color.red);
+			paintPoint(g2d, pointingPmath);
+		}
+
+		for (ND nd : normdist) {
+			nd.paintND(g2d, this);
+		}
+
+		if (p2 < 0.05) {
+			g2d.setColor(Color.cyan);
+		} else {
+			g2d.setColor(Color.YELLOW);
+		}
+		for (int i = -2; i < 3; i++)
+			for (int j = -2; j < 3; j++) {
+				// g2d.drawRect(10, 50, 100, 10);
+				g2d.drawString("t (" + String.format("%4.2f", df2) + ") = " + String.format("%5.3f", welch_t),
+						(int) (-getWidth() / 2 + 30 - offset.getX() + i),
+						(int) (-getHeight() / 2 + 320 - offset.getY()) + j);
+				g2d.drawString("p = " + String.format("%5.3f", p2),
+						(int) (-getWidth() / 2 + 30 - offset.getX() + i),
+						(int) (-getHeight() / 2 + 345 - offset.getY()) + j);
+			}
+		if (p2 < 0.05) {
+			g2d.setColor(Color.blue);
+		} else {
+			g2d.setColor(Color.red);
+		}
+		// g2d.drawRect(10, 50, 100, 10);
+		g2d.drawString("t (" + String.format("%4.2f", df2) + ") = " + String.format("%5.3f", welch_t),
+				(int) (-getWidth() / 2 + 30 - offset.getX()),
+				(int) (-getHeight() / 2 + 320 - offset.getY()));
+		g2d.drawString("p = " + String.format("%5.3f", p2),
+				(int) (-getWidth() / 2 + 30 - offset.getX()),
+				(int) (-getHeight() / 2 + 345 - offset.getY()));
+	}
+
+	private void updateNormDist() {
+		for (ND nd : normdist) {
+			nd.updateNormDist();
+		}
+		updateTdist();
+	}
+
+	double welch_t;
+	double df2;
+	double p2;
+
+	private void updateTdist() {
+		welch_t = Ttest.welch_t(normdist[1].data(), normdist[0].data());
+		df2 = Ttest.welch_degree_of_freedom(normdist[1].data(), normdist[0].data());
+		p2 = Ttest.tdist(welch_t, df2, 2);
+		// System.out.println("p2 = "+p2);
+	}
+
+	public void paintPoint(Graphics2D g2d, Point2D p) {
+		g2d.setColor(Color.red);
+		g2d.fillOval((int) (p.getX() - WelchTtest.psize / 2),
+				(int) (-(p.getY() + WelchTtest.psize / 2)), WelchTtest.psize, WelchTtest.psize);
+		// g2d.drawString(String.valueOf(num), (int)p.getX()+10, (int)p.getY());
+	}
+
+	public void paintGrid(Graphics2D g2d) {
+		g2d.setColor(new Color(230, 230, 230));
+
+		g2d.translate(getWidth() / 2 + offset.getX(), getHeight() / 2 + offset.getY());
+		// System.out.println(g2d.getTransform().getTranslateX()+"
+		// "+g2d.getTransform().getTranslateY());
+
+		for (int i = 0; i < getWidth(); i += 20) {
+			g2d.drawLine(i, -getHeight(), i, getHeight());
+			g2d.drawLine(-i, -getHeight(), -i, getHeight());
+		}
+		for (int i = 0; i < getHeight(); i += 20) {
+			g2d.drawLine(-getWidth(), i, getWidth(), i);
+			g2d.drawLine(-getWidth(), -i, getWidth(), -i);
+		}
+		g2d.setColor(Color.black);
+		g2d.drawLine(0, getHeight() * 3, 0, -getHeight() * 3);
+		g2d.drawLine(-getWidth() * 3, 0, getWidth() * 3, 0);
+
+		// g2d.translate(-(getWidth()/2+offset.getX()), -(getHeight()/2+offset.getY()));
+	}
+
+	public Point2D scr2math(Point2D p) {
+		double x = p.getX();
+		double y = p.getY();
+		x = x - offset.getX() - getWidth() / 2;
+		y = y - offset.getY() - getHeight() / 2;
+		y = -y;
+		// System.out.println("scr2math "+x+", "+y);
+		return new Point2D.Double(x, y);
+	}
+
+	public Point2D math2scr(Point2D p) {
+		return new Point2D.Double(p.getX(), -p.getY());
+	}
+
+	public void mouseClicked(MouseEvent e) {
+		if (e.getButton() == 3) {
+			Point2D pointing = findPointing(e.getPoint());
+			if (pointing == null)
+				normdist[0].points.add(scr2math(e.getPoint()));
+			else {
+				if (normdist[0].points.size() > 2)
+					normdist[0].points.remove(pointing);
+			}
+			updateNormDist();
+			repaint();
+		}
+	}
+
+	public void mouseEntered(MouseEvent e) {
+	}
+
+	public void mouseExited(MouseEvent e) {
+	}
+
+	public Point2D findPointing(Point2D mp) {
+		// Point2D nearest = null;
+		Point2D mPmath = scr2math(mp);
+		Point2D nP = null;
+		for (ND n : normdist) {
+			nP = n.nearestPoint(mPmath);
+			if (nP != null)
+				break;
+		}
+		return nP;
+		// pointingPmath = nP;
+
+		// for (Point2D p : points) {
+		// if (mPmath.distance(p) < 8) {
+		// nearest = p;
+		// }
+		// }
+		// return nearest;
+	}
+
+	public void mousePressed(MouseEvent e) {
+		mouseMoved(e);
+	}
+
+	public void mouseReleased(MouseEvent e) {
+		pointingPmath = null;
+		repaint();
+	}
+
+	public void mouseDragged(MouseEvent e) {
+		if (pointingPmath != null) {
+			pointingPmath.setLocation(scr2math(e.getPoint()));
+			updateNormDist();
+			repaint();
+		} else {
+			// e.translatePoint((int)offset.getX(), (int)offset.getY());
+			offset.setLocation(offset.getX() + (e.getPoint().getX() - pressP.getX()),
+					offset.getY() + (e.getPoint().getY() - pressP.getY()));
+			pressP = e.getPoint();
+			updateNormDist();
+			repaint();
+		}
+	}
+
+	public void mouseMoved(MouseEvent e) {
+		scr2math(e.getPoint());
+		pressP = e.getPoint();
+		Point2D pressPmath = scr2math(pressP);
+		Point2D nP = null;
+		for (ND n : normdist) {
+			nP = n.nearestPoint(pressPmath);
+			if (nP != null)
+				break;
+		}
+		pointingPmath = nP;
+		updateNormDist();
+		repaint();
+	}
+
+	@Override
+	public void keyTyped(KeyEvent e) {
+		// TODO Auto-generated method stub
+
+	}
+
+	@Override
+	public void keyPressed(KeyEvent e) {
+		if (e.getKeyCode() == KeyEvent.VK_ENTER) {
+			System.out.println(e.getKeyCode());
+
+			normdist[0] = new ND(Color.blue, 0, 0);
+			normdist[1] = new ND(Color.green, 20, -30);
+			updateNormDist();
+			repaint();
+		}
+
+	}
+
+	@Override
+	public void keyReleased(KeyEvent e) {
+		// TODO Auto-generated method stub
+
+	}
+
+}
+
+class ND {
+	ArrayList<Point2D> points;
+	Color color;
+	int offsetx = 0;
+	int offsety = 0;
+
+	public ND(Color c, int _offsetx, int _offsety) {
+		color = c;
+		offsetx = _offsetx;
+		offsety = _offsety;
+		points = new ArrayList<Point2D>();
+
+		Random rand = new Random();
+		for (int i = 0; i < 7; i++) {
+			int randx = rand.nextInt(-40 + offsetx, 40 + offsetx);
+			int randy = rand.nextInt(-10 + offsety, offsety);
+			points.add(new Point2D.Double(randx, randy));
+		}
+		updateNormDist();
+	}
+
+	double[] ddat;
+
+	public double[] data() {
+		return ddat;
+	}
+
+	// 平均と分散
+	double xavg = 0;
+	double xvarp = 1;
+
+	/**
+	 * ガウス関数、ただし、μとσ^2は、xavg, xvarp から計算する
+	 * 
+	 * @param x
+	 * @return
+	 */
+	public double gauss_function(double x) {
+		double d1 = 1.0 / Math.sqrt(2 * Math.PI * xvarp);
+		double d2 = Math.exp(-Math.pow(x - xavg, 2) / (2 * xvarp));
+		double ret = d1 * d2 * 10000;
+		// System.out.println(ret);
+		return ret;
+	}
+
+	/**
+	 * 点のx座標から、ガウス関数のパラメータ μとσ^2は、xavg, xvarp を更新する
+	 */
+	public void updateNormDist() {
+		ddat = new double[points.size()];
+		int i = 0;
+		for (Point2D p : points) {
+			ddat[i] = p.getX();
+			i++;
+		}
+		// 平均値を更新する
+		xavg = Ttest.avg(ddat);
+		// 標準偏差を更新する
+		xvarp = Ttest.varp(ddat);
+		// System.out.println("μ " + xavg + " σ^2 " + xvarp);
+	}
+
+	public void paintND(Graphics2D g2d, WelchTtest wtest) {
+
+		g2d.setColor(Color.black);
+		for (Point2D p : points) {
+			paintPoint(g2d, p);
+		}
+
+		Point2D prep = null;
+		g2d.setColor(color);
+		for (double x = -wtest.getWidth() / 2 - wtest.offset.getX(); x < wtest.getWidth() / 2
+				- wtest.offset.getX(); x += 1.0) {
+			Point2D p1 = wtest.math2scr(new Point2D.Double(x, gauss_function(x)));
+			if (prep == null)
+				prep = p1;
+			g2d.drawLine((int) p1.getX(), (int) p1.getY(), (int) prep.getX(), (int) prep.getY());
+			prep = p1;
+		}
+		if (offsetx > 10) {
+			g2d.drawString("μ = " + String.format("%6.4f", xavg), (int) (wtest.getWidth() / 5 - wtest.offset.getX()),
+					(int) (-wtest.getHeight() / 2 + 20 - wtest.offset.getY()));
+			g2d.drawString("σ = " + String.format("%6.4f", Math.sqrt(xvarp)),
+					(int) (wtest.getWidth() / 5 - wtest.offset.getX()),
+					(int) (-wtest.getHeight() / 2 + 38 - wtest.offset.getY()));
+			g2d.drawString("σ^2 = " + String.format("%6.4f", xvarp), (int) (wtest.getWidth() / 5 - wtest.offset.getX()),
+					(int) (-wtest.getHeight() / 2 + 56 - wtest.offset.getY()));
+
+		} else {
+			g2d.drawString("μ = " + String.format("%6.4f", xavg), (int) (-wtest.getWidth() / 2 + 10 - wtest.offset.getX()),
+					(int) (-wtest.getHeight() / 2 + 20 - wtest.offset.getY()));
+			g2d.drawString("σ = " + String.format("%6.4f", Math.sqrt(xvarp)),
+					(int) (-wtest.getWidth() / 2 + 10 - wtest.offset.getX()),
+					(int) (-wtest.getHeight() / 2 + 38 - wtest.offset.getY()));
+			g2d.drawString("σ^2 = " + String.format("%6.4f", xvarp), (int) (-wtest.getWidth() / 2 + 10 - wtest.offset.getX()),
+					(int) (-wtest.getHeight() / 2 + 56 - wtest.offset.getY()));
+		}
+
+	}
+
+	public void paintPoint(Graphics2D g2d, Point2D p) {
+		g2d.fillOval((int) (p.getX() - WelchTtest.psize / 2),
+				(int) (-(p.getY() + WelchTtest.psize / 2)), WelchTtest.psize, WelchTtest.psize);
+		// g2d.drawString(String.valueOf(num), (int)p.getX()+10, (int)p.getY());
+	}
+
+	public Point2D nearestPoint(Point2D pressPmath) {
+		Point2D nearest = null;
+		for (Point2D p : points) {
+			if (pressPmath.distance(p) < 8) {
+				nearest = p;
+			}
+		}
+		return nearest;
+	}
+
+}