Service Provider for applying enhancements

cdm/core/build.gradle

@@ -8,7 +8,7 @@ apply from: "$rootDir/gradle/any/protobuf.gradle"
 
 dependencies {
   api enforcedPlatform(project(':netcdf-java-platform'))
-  implementation 'commons-math:commons-math'
+  implementation 'org.apache.commons:commons-math3'
 
   testImplementation enforcedPlatform(project(':netcdf-java-testing-platform'))
 

cdm/core/src/main/java/ucar/nc2/dataset/VariableDS.java

@@ -34,6 +34,8 @@
  */
 public class VariableDS extends Variable implements VariableEnhanced, EnhanceScaleMissingUnsigned {
 
+
+
   /**
    * Constructor when there's no underlying variable.
    * You must also set the values by doing one of:
@@ -269,8 +271,10 @@ Array convert(Array data, Set<NetcdfDataset.Enhance> enhancements) {
       // datatype of the result depends on what enhancements were applied
       DataType convertedType = data.getDataType();
 
+
       // TODO: change to a provider for extensible Enhancements
       List<Enhancement> toApply = new ArrayList<>();
+
       if (enhancements.contains(Enhance.ConvertUnsigned) && unsignedConversion != null) {
         toApply.add(unsignedConversion);
         convertedType = unsignedConversion.getOutType();
@@ -283,15 +287,9 @@ Array convert(Array data, Set<NetcdfDataset.Enhance> enhancements) {
         toApply.add(scaleOffset);
         convertedType = scaleOffset.getScaledOffsetType();
       }
-      if (enhancements.contains(Enhance.ApplyStandardizer) && standardizer != null) {
-        toApply.add(standardizer);
-      }
-      if (enhancements.contains(Enhance.ApplyNormalizer) && normalizer != null) {
-        toApply.add(normalizer);
-      }
-      if (enhancements.contains(Enhance.ApplyClassifier) && classifier != null) {
-        toApply.add(classifier);
-      }
+
+      toApply.addAll(loadedEnhancements);
+
 
       double[] dataArray = (double[]) data.get1DJavaArray(DataType.DOUBLE);
 
@@ -866,9 +864,8 @@ public Array convert(Array in, boolean convertUnsigned, boolean applyScaleOffset
   // TODO make immutable in version 6
   private UnsignedConversion unsignedConversion;
   private ScaleOffset scaleOffset;
-  private Standardizer standardizer;
-  private Normalizer normalizer;
-  private Classifier classifier;
+  private List<Enhancement> loadedEnhancements = new ArrayList<>();
+
   private ConvertMissing convertMissing;
   private Set<Enhance> enhanceMode = EnumSet.noneOf(Enhance.class); // The set of enhancements that were made.
 
@@ -935,18 +932,14 @@ private void createEnhancements() {
       }
       this.dataType = scaleOffset != null ? scaleOffset.getScaledOffsetType() : this.dataType;
     }
-    Attribute standardizerAtt = findAttribute(CDM.STANDARDIZE);
-    if (standardizerAtt != null && this.enhanceMode.contains(Enhance.ApplyStandardizer) && dataType.isFloatingPoint()) {
-      this.standardizer = Standardizer.createFromVariable(this);
-    }
-    Attribute normalizerAtt = findAttribute(CDM.NORMALIZE);
-    if (normalizerAtt != null && this.enhanceMode.contains(Enhance.ApplyNormalizer) && dataType.isFloatingPoint()) {
-      this.normalizer = Normalizer.createFromVariable(this);
-    }
-    Attribute classifierAtt = findAttribute(CDM.CLASSIFY);
-    if (classifierAtt != null && this.enhanceMode.contains(Enhance.ApplyClassifier) && dataType.isNumeric()) {
-      this.classifier = Classifier.createFromVariable(this);
+    for (Enhance enhance : this.enhanceMode) {
+      for (EnhancementProvider service : ServiceLoader.load(EnhancementProvider.class)) {
+        if (service.appliesTo(enhance, this.attributes(), dataType)) {
+          loadedEnhancements.add(service.create(this));
+        }
+      }
     }
+
   }
 
   public Builder<?> toBuilder() {

cdm/core/src/main/java/ucar/nc2/filter/Classifier.java

@@ -1,20 +1,28 @@
 package ucar.nc2.filter;
 
-
 import ucar.ma2.Array;
 import ucar.ma2.IndexIterator;
-import ucar.nc2.Variable;
 import ucar.nc2.constants.CDM;
 import ucar.nc2.Attribute;
+import ucar.nc2.dataset.NetcdfDataset.Enhance;
+import ucar.nc2.dataset.VariableDS;
 import ucar.nc2.util.Misc;
 import java.util.ArrayList;
 import java.util.List;
+import ucar.ma2.*;
+import ucar.nc2.*;
 
 
 public class Classifier implements Enhancement {
+
+
   private String[] AttCat;
   private List<int[]> rules = new ArrayList<>();
 
+  private static String name = "Classifier";
+
+
+
   public Classifier() {
     this.AttCat = new String[0];
     this.rules = new ArrayList<>();
@@ -27,7 +35,8 @@ public Classifier(String[] AttCat) {
   }
 
   // Factory method to create a Classifier from a Variable
-  public static Classifier createFromVariable(Variable var) {
+
+  public static Classifier createFromVariable(VariableDS var) {
     List<Attribute> attributes = var.attributes().getAttributes();
 
     for (Attribute attribute : attributes) {
@@ -116,4 +125,18 @@ public static int[] stringToIntArray(String str) {
     return intArray;
   }
 
+  public static class Provider implements EnhancementProvider {
+    @Override
+    public boolean appliesTo(Enhance enhance, AttributeContainer attributes, DataType dt) {
+      return enhance == Enhance.ApplyClassifier && attributes.findAttribute(CDM.CLASSIFY) != null && dt.isNumeric();
+    }
+
+    @Override
+    public Classifier create(VariableDS var) {
+      return createFromVariable(var);
+    }
+  }
+
 }
+
+

cdm/core/src/main/java/ucar/nc2/filter/EnhancementProvider.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2021 University Corporation for Atmospheric Research/Unidata
+ * See LICENSE for license information.
+ */
+
+package ucar.nc2.filter;
+
+import ucar.ma2.*;
+import ucar.nc2.*;
+import ucar.nc2.dataset.NetcdfDataset.Enhance;
+import ucar.nc2.dataset.VariableDS;
+
+
+/**
+ * A Service Provider of {@link Enhancement}.
+ */
+public interface EnhancementProvider {
+
+  boolean appliesTo(Enhance enhance, AttributeContainer attributes, DataType dt);
+
+  Enhancement create(VariableDS var);
+
+
+}
+
+

cdm/core/src/main/java/ucar/nc2/filter/Normalizer.java

@@ -3,18 +3,23 @@
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
-
-import org.apache.commons.math.stat.descriptive.SummaryStatistics;
+import ucar.nc2.constants.CDM;
+import java.util.Set;
+import org.apache.commons.math3.stat.descriptive.SummaryStatistics;
 import ucar.ma2.Array;
 import ucar.ma2.DataType;
 import ucar.ma2.IndexIterator;
+import ucar.nc2.AttributeContainer;
+import ucar.nc2.Variable;
+import ucar.nc2.dataset.NetcdfDataset.Enhance;
 import ucar.nc2.dataset.VariableDS;
 
 public class Normalizer implements Enhancement {
 
   private final ScaleOffset scaleOffset;
   private final double minimum;
   private final double range; // maximum - minimum
+  private static String name = "Normalizer";
 
   public static Normalizer createFromVariable(VariableDS var) {
     try {
@@ -72,4 +77,22 @@ public double getRange() {
     return range;
   }
 
+  public static class Provider implements EnhancementProvider {
+
+
+    @Override
+    public boolean appliesTo(Enhance enhance, AttributeContainer attributes, DataType dt) {
+      return enhance == Enhance.ApplyNormalizer && attributes.findAttribute(CDM.NORMALIZE) != null
+          && dt.isFloatingPoint();
+    }
+
+    @Override
+    public Normalizer create(VariableDS var) {
+      return Normalizer.createFromVariable(var);
+    }
+
+
+
+  }
+
 }

cdm/core/src/main/java/ucar/nc2/filter/ScaleOffset.java

@@ -290,5 +290,8 @@ public int getId() {
     public Filter create(Map<String, Object> properties) {
       return new ScaleOffset(properties);
     }
+
   }
+
+
 }

cdm/core/src/main/java/ucar/nc2/filter/Standardizer.java

@@ -3,18 +3,23 @@
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
+import ucar.nc2.constants.CDM;
 
-import org.apache.commons.math.stat.descriptive.SummaryStatistics;
+import java.util.Set;
+import org.apache.commons.math3.stat.descriptive.SummaryStatistics;
 import ucar.ma2.Array;
 import ucar.ma2.DataType;
 import ucar.ma2.IndexIterator;
+import ucar.nc2.AttributeContainer;
+import ucar.nc2.dataset.NetcdfDataset.Enhance;
 import ucar.nc2.dataset.VariableDS;
 
 public class Standardizer implements Enhancement {
 
   private final ScaleOffset scaleOffset;
   private final double mean;
   private final double stdDev;
+  private static String name = "Standardizer";
 
   public static Standardizer createFromVariable(VariableDS var) {
     try {
@@ -71,5 +76,22 @@ public double getMean() {
   public double getStdDev() {
     return stdDev;
   }
+
+
+
+  public static class Provider implements EnhancementProvider {
+
+
+    @Override
+    public boolean appliesTo(Enhance enhance, AttributeContainer attributes, DataType dt) {
+      return enhance == Enhance.ApplyStandardizer && attributes.findAttribute(CDM.STANDARDIZE) != null
+          && dt.isFloatingPoint();
+    }
+
+    @Override
+    public Standardizer create(VariableDS var) {
+      return createFromVariable(var);
+    }
+  }
 }
 

cdm/core/src/main/resources/META-INF/services/ucar.nc2.filter.EnhancementProvider

@@ -0,0 +1,6 @@
+ucar.nc2.filter.Classifier$Provider
+ucar.nc2.filter.Standardizer$Provider
+ucar.nc2.filter.Normalizer$Provider
+
+
+

cdm/core/src/test/java/ucar/nc2/ncml/TestEnhanceClassifier.java

@@ -12,6 +12,7 @@
 import ucar.nc2.NetcdfFile;
 import ucar.nc2.Variable;
 import ucar.nc2.dataset.NetcdfDatasets;
+import ucar.nc2.dataset.VariableDS;
 import ucar.nc2.filter.Classifier;
 import ucar.unidata.util.test.TestDir;
 
@@ -33,7 +34,7 @@ public void testEnhanceClassifier_Ints() throws IOException {
       assertThat((Object) classifySpecs).isNotNull();
       assertThat(!classifySpecs.attributes().isEmpty()).isTrue();
       Array Data = classifySpecs.read();
-      Classifier classifier = Classifier.createFromVariable(classifySpecs);
+      Classifier classifier = Classifier.createFromVariable((VariableDS) classifySpecs);
       int[] ClassifiedArray = classifier.classifyWithAttributes(Data);
       assertThat(nearlyEquals(Array.makeFromJavaArray(ClassifiedArray), DATA_mixNumbers)).isTrue();
 
@@ -53,7 +54,7 @@ public void testEnhanceClassifier_Floats() throws IOException {
       assertThat((Object) classifySpecs).isNotNull();
       assertThat(!classifySpecs.attributes().isEmpty()).isTrue();
       Array Data = classifySpecs.read();
-      Classifier classifier = Classifier.createFromVariable(classifySpecs);
+      Classifier classifier = Classifier.createFromVariable((VariableDS) classifySpecs);
       int[] ClassifiedArray = classifier.classifyWithAttributes(Data);
       assertThat(nearlyEquals(Array.makeFromJavaArray(ClassifiedArray), DATA_mixNumbers)).isTrue();
 
@@ -73,7 +74,7 @@ public void testEnhanceClassifier_classification() throws IOException {
       assertThat((Object) classifySpecs).isNotNull();
       assertThat(!classifySpecs.attributes().isEmpty()).isTrue();
       Array Data = classifySpecs.read();
-      Classifier classifier = Classifier.createFromVariable(classifySpecs);
+      Classifier classifier = Classifier.createFromVariable((VariableDS) classifySpecs);
       int[] ClassifiedArray = classifier.classifyWithAttributes(Data);
       assertThat(nearlyEquals(Array.makeFromJavaArray(ClassifiedArray), CLASSIFICATION_TEST)).isTrue();
 

netcdf-java-platform/build.gradle

@@ -37,7 +37,7 @@ dependencies {
     api 'com.beust:jcommander:1.78'
 
     // cdm-core
-    api 'commons-math:commons-math:1.2'
+    api 'org.apache.commons:commons-math3:3.6.1'
 
     // cdm-grib
     api 'edu.ucar:jj2000:5.4'