Fix to include also the first scan in case the retention time is 0.

chemclipse/plugins/org.eclipse.chemclipse.xxd.filter/src/org/eclipse/chemclipse/xxd/filter/core/CoordinateEvaluator.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2025 Lablicate GmbH.
+ * Copyright (c) 2025, 2026 Lablicate GmbH.
  *
  * This program and the accompanying materials are made
  * available under the terms of the Eclipse Public License 2.0
@@ -34,7 +34,11 @@ public static boolean isMatchPeak(IPeak peak, CoordinateOption coordinateOption,
 	public static boolean isMatchScan(IScan scan, CoordinateOption coordinateOption, RangeOption rangeOption, double coordinateValue) {
 
 		if(scan != null) {
-			double targetValue = 0;
+			/*
+			 * Use -1 as 0 is a valid retention time,
+			 * in most cases when GC-FID is used.
+			 */
+			double targetValue = -1;
 			switch(coordinateOption) {
 				case RETENTION_TIME_MS:
 					targetValue = scan.getRetentionTime();
@@ -43,15 +47,22 @@ public static boolean isMatchScan(IScan scan, CoordinateOption coordinateOption,
 					targetValue = scan.getRetentionTime() / IChromatogramOverview.MINUTE_CORRELATION_FACTOR;
 					break;
 				case RETENTION_INDEX:
-					targetValue = scan.getRetentionIndex();
+					/*
+					 * The retention index is 0 by default if not set.
+					 * Allowing 0 could lead to an empty chromatogram.
+					 */
+					double retentionIndex = scan.getRetentionIndex();
+					if(retentionIndex > 0) {
+						targetValue = retentionIndex;
+					}
 					break;
 				default:
 					break;
 			}
 			/*
 			 * Validate
 			 */
-			if(targetValue > 0) {
+			if(targetValue > -1) {
 				return isMatch(targetValue, rangeOption, coordinateValue);
 			}
 		}

chemclipse/tests/org.eclipse.chemclipse.xxd.filter.fragment.test/src/org/eclipse/chemclipse/xxd/filter/core/CoordinateEvaluator_6_Test.java

@@ -0,0 +1,59 @@
+/*******************************************************************************
+ * Copyright (c) 2026 Lablicate GmbH.
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ * 
+ * Contributors:
+ * Philip Wenig - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.chemclipse.xxd.filter.core;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.eclipse.chemclipse.model.core.IScan;
+import org.eclipse.chemclipse.xxd.filter.model.CoordinateOption;
+import org.eclipse.chemclipse.xxd.filter.model.RangeOption;
+import org.junit.jupiter.api.Test;
+
+public class CoordinateEvaluator_6_Test extends CoordinateEvaluatorTestCase {
+
+	@Test
+	public void test1() {
+
+		IScan scan = createScan(0, 0);
+		assertTrue(CoordinateEvaluator.isMatchScan(scan, CoordinateOption.RETENTION_TIME_MS, RangeOption.LOWER, 1000));
+	}
+
+	@Test
+	public void test2() {
+
+		IScan scan = createScan(0, 0);
+		assertTrue(CoordinateEvaluator.isMatchScan(scan, CoordinateOption.RETENTION_TIME_MIN, RangeOption.LOWER, 1));
+	}
+
+	@Test
+	public void test3() {
+
+		IScan scan = createScan(0, 0);
+		assertFalse(CoordinateEvaluator.isMatchScan(scan, CoordinateOption.RETENTION_INDEX, RangeOption.LOWER, 1));
+	}
+
+	@Test
+	public void test4() {
+
+		IScan scan = createScan(0, 1);
+		assertFalse(CoordinateEvaluator.isMatchScan(scan, CoordinateOption.RETENTION_INDEX, RangeOption.LOWER, 1));
+	}
+
+	@Test
+	public void test5() {
+
+		IScan scan = createScan(0, 1);
+		assertTrue(CoordinateEvaluator.isMatchScan(scan, CoordinateOption.RETENTION_INDEX, RangeOption.LOWER, 2));
+	}
+}