Add ArraySavingListener for debugging (#114)

Signed-off-by: AlexDBlack <blacka101@gmail.com>

nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/autodiff/listeners/debugging/ArraySavingListener.java

@@ -0,0 +1,107 @@
+package org.nd4j.autodiff.listeners.debugging;
+
+import lombok.NonNull;
+import org.nd4j.autodiff.listeners.At;
+import org.nd4j.autodiff.listeners.BaseListener;
+import org.nd4j.autodiff.listeners.Operation;
+import org.nd4j.autodiff.samediff.SameDiff;
+import org.nd4j.autodiff.samediff.internal.SameDiffOp;
+import org.nd4j.base.Preconditions;
+import org.nd4j.linalg.api.ndarray.INDArray;
+import org.nd4j.linalg.dataset.api.MultiDataSet;
+import org.nd4j.linalg.factory.Nd4j;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class ArraySavingListener extends BaseListener {
+
+    protected final File dir;
+    protected int count = 0;
+
+    public ArraySavingListener(@NonNull File dir){
+
+        if(!dir.exists()){
+            dir.mkdir();
+        }
+
+        if(dir.listFiles() != null && dir.listFiles().length > 0){
+            throw new IllegalStateException("Directory is not empty: " + dir.getAbsolutePath());
+        }
+
+        this.dir = dir;
+    }
+
+    @Override
+    public boolean isActive(Operation operation) {
+        return true;
+    }
+
+
+    @Override
+    public void opExecution(SameDiff sd, At at, MultiDataSet batch, SameDiffOp op, INDArray[] outputs) {
+        List<String> outNames = op.getOutputsOfOp();
+        for(int i=0; i<outputs.length; i++ ){
+            String filename = (count++) + "_" + outNames.get(i).replaceAll("/", "__") + ".bin";
+            File outFile = new File(dir, filename);
+
+            INDArray arr = outputs[i];
+            try {
+                Nd4j.saveBinary(arr, outFile);
+                System.out.println(outFile.getAbsolutePath());
+            } catch (IOException e){
+                throw new RuntimeException(e);
+            }
+        }
+    }
+
+    public static void compare(File dir1, File dir2, double eps) throws Exception {
+        File[] files1 = dir1.listFiles();
+        File[] files2 = dir2.listFiles();
+        Preconditions.checkNotNull(files1, "No files in directory 1: %s", dir1);
+        Preconditions.checkNotNull(files2, "No files in directory 2: %s", dir2);
+        Preconditions.checkState(files1.length == files2.length, "Different number of files: %s vs %s", files1.length, files2.length);
+
+        Map<String,File> m1 = toMap(files1);
+        Map<String,File> m2 = toMap(files2);
+
+        for(File f : files1){
+            String name = f.getName();
+            String varName = name.substring(name.indexOf('_') + 1, name.length()-4); //Strip "x_" and ".bin"
+            File f2 = m2.get(varName);
+
+            INDArray arr1 = Nd4j.readBinary(f);
+            INDArray arr2 = Nd4j.readBinary(f2);
+
+            //TODO String arrays won't work here!
+            boolean eq = arr1.equalsWithEps(arr2, eps);
+            if(eq){
+                System.out.println("Equals: " + varName.replaceAll("__", "/"));
+            } else {
+                INDArray sub = arr1.sub(arr2);
+                INDArray diff = Nd4j.math.abs(sub);
+                double maxDiff = diff.maxNumber().doubleValue();
+                System.out.println("FAILS: " + varName.replaceAll("__", "/") + " - max difference = " + maxDiff);
+                System.out.println("\t" + f.getAbsolutePath());
+                System.out.println("\t" + f2.getAbsolutePath());
+                sub.close();
+                diff.close();;
+            }
+            arr1.close();
+            arr2.close();
+        }
+    }
+
+    private static Map<String,File> toMap(File[] files){
+        Map<String,File> ret = new HashMap<>();
+        for(File f : files) {
+            String  name = f.getName();
+            String varName = name.substring(name.indexOf('_') + 1, name.length() - 4); //Strip "x_" and ".bin"
+            ret.put(varName, f);
+        }
+        return ret;
+    }
+}