diff --git a/jtstoolkit/src/main/java/ec/tstoolkit/stats/NiidTests.java b/jtstoolkit/src/main/java/ec/tstoolkit/stats/NiidTests.java
index 28a19aacb..d17d22fed 100644
--- a/jtstoolkit/src/main/java/ec/tstoolkit/stats/NiidTests.java
+++ b/jtstoolkit/src/main/java/ec/tstoolkit/stats/NiidTests.java
@@ -13,8 +13,7 @@
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and 
 * limitations under the Licence.
-*/
-
+ */
 package ec.tstoolkit.stats;
 
 import ec.tstoolkit.data.DataBlock;
@@ -39,20 +38,20 @@ public class NiidTests {
     // / <param name="nhp">Number of hyper-parameters. Could be 0</param>
 
     /**
-     * 
+     *
      * @param freq
      * @return
      */
-    public static int calcLBLength(int freq)
-    {
-	int n = 0;
-	if (freq == 12)
-	    n = 24;
-	else if (freq == 1)
-	    n = 8;
-	else
-	    n = 4 * freq;
-	return n;
+    public static int calcLBLength(int freq) {
+        int n = 0;
+        if (freq == 12) {
+            n = 24;
+        } else if (freq == 1) {
+            n = 8;
+        } else {
+            n = 4 * freq;
+        }
+        return n;
     }
 
     private DescriptiveStatistics stats;
@@ -83,394 +82,374 @@ else if (freq == 1)
     private boolean m_seas;
 
     /**
-     * 
+     *
      * @param data
      * @param freq
      * @param nhp
      * @param seas
      */
-    public NiidTests(IReadDataBlock data, int freq, int nhp, boolean seas)
-    {
-	stats = new DescriptiveStatistics(data);
-	m_freq = freq;
-	m_seas = seas;
-	m_nhp = nhp;
-	ac = new AutoCorrelations(stats);
-	ac.setKMax(calcLBLength(freq <= 1 ? 6 : freq));
-	calcAC2();
-	ac2.setKMax(calcLBLength(freq <= 1 ? 6 : freq));
+    public NiidTests(IReadDataBlock data, int freq, int nhp, boolean seas) {
+        stats = new DescriptiveStatistics(data);
+        m_freq = freq;
+        m_seas = seas && freq > 1;
+        m_nhp = nhp;
+        ac = new AutoCorrelations(stats);
+        ac.setKMax(calcLBLength(freq <= 1 ? 6 : freq));
+        calcAC2();
+        ac2.setKMax(calcLBLength(freq <= 1 ? 6 : freq));
     }
 
     private void calcAC2() {
-	double[] data = stats.internalStorage();
-	double[] d2 = new double[data.length];
-	for (int i = 0; i < d2.length; ++i) {
-	    double cur = data[i];
-	    if (Double.isFinite(cur))
-		d2[i] = cur * cur;
-	    else
-		d2[i] = Double.NaN;
-	}
-	ac2 = new AutoCorrelations(new DataBlock(d2));
-	ac2.setCorrectedForMean(true);
+        double[] data = stats.internalStorage();
+        double[] d2 = new double[data.length];
+        for (int i = 0; i < d2.length; ++i) {
+            double cur = data[i];
+            if (Double.isFinite(cur)) {
+                d2[i] = cur * cur;
+            } else {
+                d2[i] = Double.NaN;
+            }
+        }
+        ac2 = new AutoCorrelations(new DataBlock(d2));
+        ac2.setCorrectedForMean(true);
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public AutoCorrelations getAutoCorrelations()
-    {
-	return ac;
+    public AutoCorrelations getAutoCorrelations() {
+        return ac;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public AutoCorrelations getAutoCorrelationsOnSquare()
-    {
-	return ac2;
+    public AutoCorrelations getAutoCorrelationsOnSquare() {
+        return ac2;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public BoxPierceTest getBoxPierce()
-    {
+    public BoxPierceTest getBoxPierce() {
 
-	if (m_bp == null)
+        if (m_bp == null)
 	    try {
-		int k = m_k != 0 ? m_k : calcLBLength(m_freq);
-
-		m_bp = new BoxPierceTest();
-		m_bp.setHyperParametersCount(m_nhp);
-		m_bp.setLag(1);
-		m_bp.setK(k);
-		m_bp.test(ac);
-	    } catch (StatException ex) {
-		m_bp = null;
-		return null;
-	    } catch (DStatException ex) {
-		m_runs = null;
-		return null;
-	    }
-	return m_bp.isValid() ? m_bp : null;
+            int k = m_k != 0 ? m_k : calcLBLength(m_freq);
+
+            m_bp = new BoxPierceTest();
+            m_bp.setHyperParametersCount(m_nhp);
+            m_bp.setLag(1);
+            m_bp.setK(k);
+            m_bp.test(ac);
+        } catch (StatException ex) {
+            m_bp = null;
+            return null;
+        } catch (DStatException ex) {
+            m_runs = null;
+            return null;
+        }
+        return m_bp.isValid() ? m_bp : null;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public BoxPierceTest getBoxPierceOnSquare()
-    {
-	if (m_bp2 == null)
+    public BoxPierceTest getBoxPierceOnSquare() {
+        if (m_bp2 == null)
 	    try {
-		int k = m_k != 0 ? m_k : calcLBLength(m_freq);
-
-		m_bp2 = new BoxPierceTest();
-		m_bp2.setHyperParametersCount(m_nhp);
-		m_bp2.setLag(1);
-		m_bp2.setK(k);
-		m_bp2.test(ac2);
-	    } catch (StatException ex) {
-		m_bp2 = null;
-		return null;
-	    } catch (DStatException ex) {
-		m_runs = null;
-		return null;
-	    }
-	return m_bp2.isValid() ? m_bp2 : null;
+            int k = m_k != 0 ? m_k : calcLBLength(m_freq);
+
+            m_bp2 = new BoxPierceTest();
+            m_bp2.setHyperParametersCount(m_nhp);
+            m_bp2.setLag(1);
+            m_bp2.setK(k);
+            m_bp2.test(ac2);
+        } catch (StatException ex) {
+            m_bp2 = null;
+            return null;
+        } catch (DStatException ex) {
+            m_runs = null;
+            return null;
+        }
+        return m_bp2.isValid() ? m_bp2 : null;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public int getFrequency()
-    {
-	return m_freq;
+    public int getFrequency() {
+        return m_freq;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public int getHyperParametersCount()
-    {
-	return m_nhp;
+    public int getHyperParametersCount() {
+        return m_nhp;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public int getK()
-    {
-	return m_k;
+    public int getK() {
+        return m_k;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public KurtosisTest getKurtosis()
-    {
-	if (m_kurtosis == null)
+    public KurtosisTest getKurtosis() {
+        if (m_kurtosis == null)
 	    try {
-		m_kurtosis = new KurtosisTest();
-		m_kurtosis.test(stats);
-	    } catch (StatException ex) {
-		m_kurtosis = null;
-		return null;
-	    } catch (DStatException ex) {
-		m_runs = null;
-		return null;
-	    }
-	return m_kurtosis.isValid() ? m_kurtosis : null;
+            m_kurtosis = new KurtosisTest();
+            m_kurtosis.test(stats);
+        } catch (StatException ex) {
+            m_kurtosis = null;
+            return null;
+        } catch (DStatException ex) {
+            m_runs = null;
+            return null;
+        }
+        return m_kurtosis.isValid() ? m_kurtosis : null;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public LjungBoxTest getLjungBox()
-    {
-	if (m_lb == null)
+    public LjungBoxTest getLjungBox() {
+        if (m_lb == null)
 	    try {
-		int k = m_k != 0 ? m_k : calcLBLength(m_freq);
-
-		m_lb = new LjungBoxTest();
-		m_lb.setHyperParametersCount(m_nhp);
-		m_lb.setLag(1);
-		m_lb.setK(k);
-		m_lb.test(ac);
-	    } catch (StatException ex) {
-		m_lb = null;
-		return null;
-	    }
-	return m_lb.isValid() ? m_lb : null;
+            int k = m_k != 0 ? m_k : calcLBLength(m_freq);
+
+            m_lb = new LjungBoxTest();
+            m_lb.setHyperParametersCount(m_nhp);
+            m_lb.setLag(1);
+            m_lb.setK(k);
+            m_lb.test(ac);
+        } catch (StatException ex) {
+            m_lb = null;
+            return null;
+        }
+        return m_lb.isValid() ? m_lb : null;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public LjungBoxTest getLjungBoxOnSquare()
-    {
-	if (m_lb2 == null)
+    public LjungBoxTest getLjungBoxOnSquare() {
+        if (m_lb2 == null)
 	    try {
-		int k = m_k != 0 ? m_k : calcLBLength(m_freq);
-
-		m_lb2 = new LjungBoxTest();
-		m_lb2.setHyperParametersCount(m_nhp);
-		m_lb2.setLag(1);
-		m_lb2.setK(k);
-		m_lb2.test(ac2);
-	    } catch (StatException ex) {
-		m_lb2 = null;
-		return null;
-	    } catch (DStatException ex) {
-		m_runs = null;
-		return null;
-	    }
-	return m_lb2.isValid() ? m_lb2 : null;
+            int k = m_k != 0 ? m_k : calcLBLength(m_freq);
+
+            m_lb2 = new LjungBoxTest();
+            m_lb2.setHyperParametersCount(m_nhp);
+            m_lb2.setLag(1);
+            m_lb2.setK(k);
+            m_lb2.test(ac2);
+        } catch (StatException ex) {
+            m_lb2 = null;
+            return null;
+        } catch (DStatException ex) {
+            m_runs = null;
+            return null;
+        }
+        return m_lb2.isValid() ? m_lb2 : null;
     }
 
     /**
-     * 
+     *
      * @return
-     * 
+     *
      */
-    public MeanTest getMeanTest()
-    {
-	if (m_mean == null)
+    public MeanTest getMeanTest() {
+        if (m_mean == null)
 	    try {
-		m_mean = new MeanTest();
-		m_mean.zeroMean(stats);
-	    } catch (StatException ex) {
-		m_mean = null;
-		return null;
-	    } catch (DStatException ex) {
-		m_runs = null;
-		return null;
-	    }
-	return m_mean.isValid() ? m_mean : null;
+            m_mean = new MeanTest();
+            m_mean.zeroMean(stats);
+        } catch (StatException ex) {
+            m_mean = null;
+            return null;
+        } catch (DStatException ex) {
+            m_runs = null;
+            return null;
+        }
+        return m_mean.isValid() ? m_mean : null;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public DoornikHansenTest getNormalityTest()
-    {
-	if (m_dh == null)
+    public DoornikHansenTest getNormalityTest() {
+        if (m_dh == null)
 	    try {
-		m_dh = new DoornikHansenTest();
-		m_dh.test(stats);
-	    } catch (StatException ex) {
-		m_dh = null;
-		return null;
-	    } catch (DStatException ex) {
-		m_runs = null;
-		return null;
-	    }
-	return m_dh.isValid() ? m_dh : null;
+            m_dh = new DoornikHansenTest();
+            m_dh.test(stats);
+        } catch (StatException ex) {
+            m_dh = null;
+            return null;
+        } catch (DStatException ex) {
+            m_runs = null;
+            return null;
+        }
+        return m_dh.isValid() ? m_dh : null;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public TestofRuns getRuns()
-    {
-	if (m_runs == null)
+    public TestofRuns getRuns() {
+        if (m_runs == null)
 	    try {
-		m_runs = new TestofRuns();
-		m_runs.test(stats);
-	    } catch (StatException | DStatException ex) {
-		m_runs = null;
-		return null;
-	    }
-	return m_runs.isValid() ? m_runs : null;
+            m_runs = new TestofRuns();
+            m_runs.test(stats);
+        } catch (StatException | DStatException ex) {
+            m_runs = null;
+            return null;
+        }
+        return m_runs.isValid() ? m_runs : null;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public BoxPierceTest getSeasonalBoxPierce()
-    {
-	if (!m_seas)
-	    return null;
-	if (m_bps == null)
+    public BoxPierceTest getSeasonalBoxPierce() {
+        if (!m_seas) {
+            return null;
+        }
+        if (m_bps == null)
 	    try {
-		int k = m_ks != 0 ? m_ks : 2;
-		m_bps = new BoxPierceTest();
-		m_bps.setHyperParametersCount(m_nhp);
-		m_bps.setLag(m_freq);
-		m_bps.setK(k);
-		m_bps.test(ac);
-	    } catch (StatException ex) {
-		m_bps = null;
-		return null;
-	    } catch (DStatException ex) {
-		m_runs = null;
-		return null;
-	    }
-	return m_bps.isValid() ? m_bps : null;
+            int k = m_ks != 0 ? m_ks : 2;
+            m_bps = new BoxPierceTest();
+            m_bps.setHyperParametersCount(m_nhp);
+            m_bps.setLag(m_freq);
+            m_bps.setK(k);
+            m_bps.test(ac);
+        } catch (StatException ex) {
+            m_bps = null;
+            return null;
+        } catch (DStatException ex) {
+            m_runs = null;
+            return null;
+        }
+        return m_bps.isValid() ? m_bps : null;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public LjungBoxTest getSeasonalLjungBox()
-    {
-	if (!m_seas)
-	    return null;
-	if (m_lbs == null)
+    public LjungBoxTest getSeasonalLjungBox() {
+        if (!m_seas) {
+            return null;
+        }
+        if (m_lbs == null)
 	    try {
-		int k = m_ks != 0 ? m_ks : 2;
-		m_lbs = new LjungBoxTest();
-		m_lbs.setHyperParametersCount(m_nhp);
-		m_lbs.setLag(m_freq);
-		m_lbs.setK(k);
-		m_lbs.test(ac);
-	    } catch (StatException ex) {
-		m_lbs = null;
-		return null;
-	    } catch (DStatException ex) {
-		m_runs = null;
-		return null;
-	    }
-	return m_lbs.isValid() ? m_lbs : null;
+            int k = m_ks != 0 ? m_ks : 2;
+            m_lbs = new LjungBoxTest();
+            m_lbs.setHyperParametersCount(m_nhp);
+            m_lbs.setLag(m_freq);
+            m_lbs.setK(k);
+            m_lbs.test(ac);
+        } catch (StatException ex) {
+            m_lbs = null;
+            return null;
+        } catch (DStatException ex) {
+            m_runs = null;
+            return null;
+        }
+        return m_lbs.isValid() ? m_lbs : null;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public int getsK()
-    {
-	return m_ks;
+    public int getsK() {
+        return m_ks;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public SkewnessTest getSkewness()
-    {
-	if (m_skewness == null)
+    public SkewnessTest getSkewness() {
+        if (m_skewness == null)
 	    try {
-		m_skewness = new SkewnessTest();
-		m_skewness.test(stats);
-	    } catch (StatException ex) {
-		m_skewness = null;
-		return null;
-	    } catch (DStatException ex) {
-		m_runs = null;
-		return null;
-	    }
-	return m_skewness.isValid() ? m_skewness : null;
+            m_skewness = new SkewnessTest();
+            m_skewness.test(stats);
+        } catch (StatException ex) {
+            m_skewness = null;
+            return null;
+        } catch (DStatException ex) {
+            m_runs = null;
+            return null;
+        }
+        return m_skewness.isValid() ? m_skewness : null;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public DescriptiveStatistics getStatistics()
-    {
-	return stats;
+    public DescriptiveStatistics getStatistics() {
+        return stats;
     }
 
     /**
-     * 
+     *
      * @return
      */
-    public TestofUpDownRuns getUpAndDownRuns()
-    {
-	if (m_udruns == null)
+    public TestofUpDownRuns getUpAndDownRuns() {
+        if (m_udruns == null)
 	    try {
-		m_udruns = new TestofUpDownRuns();
-		m_udruns.test(stats);
-	    } catch (StatException ex) {
-		m_udruns = null;
-		return null;
-	    } catch (DStatException ex) {
-		m_runs = null;
-		return null;
-	    }
-	return m_udruns.isValid() ? m_udruns : null;
+            m_udruns = new TestofUpDownRuns();
+            m_udruns.test(stats);
+        } catch (StatException ex) {
+            m_udruns = null;
+            return null;
+        } catch (DStatException ex) {
+            m_runs = null;
+            return null;
+        }
+        return m_udruns.isValid() ? m_udruns : null;
     }
 
     /**
-     * 
+     *
      * @param k
      */
-    public void prepare(final int k)
-    {
-	ac.setKMax(k);
-	ac2.setKMax(k);
+    public void prepare(final int k) {
+        ac.setKMax(k);
+        ac2.setKMax(k);
     }
 
     /**
-     * 
+     *
      * @param value
      */
-    public void setK(int value)
-    {
-	m_k = value;
+    public void setK(int value) {
+        m_k = value;
     }
 
     /**
-     * 
+     *
      * @param value
      */
-    public void setsK(int value)
-    {
-	m_ks = value;
+    public void setsK(int value) {
+        m_ks = value;
     }
 }