[MXNET-1385] Fix scaladoc scalastyle violations in Infer package

scala-package/infer/src/main/scala/org/apache/mxnet/infer/Classifier.scala

@@ -31,6 +31,7 @@ trait ClassifierBase {
 
   /**
     * Takes an array of floats and returns corresponding (Label, Score) tuples
+    * @tparam T The Scala equivalent of the DType used for the input array and return value
     * @param input            Indexed sequence one-dimensional array of floats/doubles
     * @param topK             (Optional) How many result (sorting based on the last axis)
     *                         elements to return. Default returns unsorted output.
@@ -167,6 +168,12 @@ class Classifier(modelPathPrefix: String,
     result.toIndexedSeq
   }
 
+  /**
+    * Gives the path to the standard location of the synset.txt file
+    * @throws IllegalArgumentException Thrown when the file does not exist
+    * @param modelPathPrefix The path to the model directory
+    * @return The path to the synset.txt file
+    */
   private[infer] def getSynsetFilePath(modelPathPrefix: String): String = {
     val dirPath = modelPathPrefix.substring(0, 1 + modelPathPrefix.lastIndexOf(File.separator))
     val d = new File(dirPath)
@@ -179,6 +186,11 @@ class Classifier(modelPathPrefix: String,
     s.getCanonicalPath
   }
 
+  /**
+    * Parses the labels from a synset file
+    * @param synsetFilePath The path to the synset file. Can be gotten from getSynsetFilePath
+    * @return A IndexedSeq of each element in the file
+    */
   private[infer]  def readSynsetFile(synsetFilePath: String): IndexedSeq[String] = {
     val f = io.Source.fromFile(synsetFilePath)
     try {
@@ -188,6 +200,11 @@ class Classifier(modelPathPrefix: String,
     }
   }
 
+  /**
+    * Creates a predictor with the same modelPath, inputDescriptors, contexts,
+    * and epoch as the classifier
+    * @return The new Predictor
+    */
   private[infer] def getPredictor(): PredictBase = {
       new Predictor(modelPathPrefix, inputDescriptors, contexts, epoch)
   }

scala-package/infer/src/main/scala/org/apache/mxnet/infer/ImageClassifier.scala

@@ -66,6 +66,10 @@ class ImageClassifier(modelPathPrefix: String,
   protected[infer] val height = inputShape(inputLayout.indexOf('H'))
   protected[infer] val width = inputShape(inputLayout.indexOf('W'))
 
+  /**
+    * Get the names and shapes that would be returns by a classify call
+    * @return a list of (name, shape) tuples
+    */
   def outputShapes: IndexedSeq[(String, Shape)] = predictor.outputShapes
 
   /**
@@ -127,6 +131,19 @@ class ImageClassifier(modelPathPrefix: String,
     result
   }
 
+  /**
+    * Creates a Classifier
+    *
+    * @param modelPathPrefix    Path prefix from where to load the model artifacts.
+    *                           These include the symbol, parameters, and synset.txt.
+    *                           Example: file://model-dir/resnet-152 (containing
+    *                           resnet-152-symbol.json, resnet-152-0000.params, and synset.txt).
+    * @param inputDescriptors   Descriptors defining the input node names, shape,
+    *                           layout and type parameters
+    * @param contexts           Device contexts on which you want to run inference; defaults to CPU
+    * @param epoch              Model epoch to load; defaults to 0
+    * @return                   A Classifier to perform inference with
+    */
   private[infer] def getClassifier(modelPathPrefix: String,
                                      inputDescriptors: IndexedSeq[DataDesc],
                     contexts: Array[Context] = Context.cpu(),
@@ -156,19 +173,16 @@ object ImageClassifier {
 
   /**
     * Convert input BufferedImage to NDArray of input shape
-    *
-    * <p>
     * Note: Caller is responsible to dispose the NDArray
     * returned by this method after the use.
-    * </p>
-    * @param resizedImage     BufferedImage to get pixels from
     *
-    * @param inputImageShape  Input shape; for example for resnet it is (3,224,224).
-                              Should be same as inputDescriptor shape.
-    * @param dType            The DataType of the NDArray created from the image
-    *                         that should be returned.
-    *                         Currently it defaults to Dtype.Float32
-    * @return                 NDArray pixels array with shape (3, 224, 224) in CHW format
+    * @param resizedImage BufferedImage to get pixels from
+    * @param inputImageShape Input shape; for example for resnet it is (3,224,224).
+    *                        Should be same as inputDescriptor shape.
+    * @param dType The DataType of the NDArray created from the image
+    *              that should be returned.
+    *              Currently it defaults to Dtype.Float32
+    * @return NDArray pixels array with shape (3, 224, 224) in CHW format
     */
   def bufferedImageToPixels(resizedImage: BufferedImage, inputImageShape: Shape,
                             dType : DType = DType.Float32): NDArray = {
@@ -235,4 +249,4 @@ object ImageClassifier {
   def loadInputBatch(inputImagePaths: List[String]): Traversable[BufferedImage] = {
     inputImagePaths.map(path => ImageIO.read(new File(path)))
   }
-}
+}

scala-package/infer/src/main/scala/org/apache/mxnet/infer/MXNetHandler.scala

@@ -23,6 +23,12 @@ import org.slf4j.LoggerFactory
 
 private[infer] trait MXNetHandler {
 
+  /**
+    * Executes a function within a thread-safe executor
+    * @param f The function to execute
+    * @tparam T The return type of the function
+    * @return Returns the result of the function f
+    */
   def execute[T](f: => T): T
 
   val executor: ExecutorService
@@ -31,7 +37,11 @@ private[infer] trait MXNetHandler {
 
 private[infer] object MXNetHandlerType extends Enumeration {
 
+  /**
+    * The internal type of the MXNetHandlerType enumeration
+    */
   type MXNetHandlerType = Value
+
   val SingleThreadHandler = Value("MXNetSingleThreadHandler")
   val OneThreadPerModelHandler = Value("MXNetOneThreadPerModelHandler")
 }
@@ -93,6 +103,10 @@ private[infer] object MXNetSingleThreadHandler extends MXNetThreadPoolHandler(1)
 
 private[infer] object MXNetHandler {
 
+  /**
+    * Creates a handler based on the handlerType
+    * @return A ThreadPool or Thread Handler
+    */
   def apply(): MXNetHandler = {
     if (handlerType == MXNetHandlerType.OneThreadPerModelHandler) {
       new MXNetThreadPoolHandler(1)

scala-package/infer/src/main/scala/org/apache/mxnet/infer/ObjectDetector.scala

@@ -111,6 +111,13 @@ class ObjectDetector(modelPathPrefix: String,
     batchResult.toIndexedSeq
   }
 
+  /**
+    * Formats detection results by sorting in descending order of accuracy (topK only)
+    * and combining with synset labels
+    * @param predictResultND The results from the objectDetect call
+    * @param topK The number of top results to return or None for all
+    * @return The top predicted results as (className, [Accuracy, Xmin, Ymin, Xmax, Ymax])
+    */
   private[infer] def sortAndReformat(predictResultND: NDArray, topK: Option[Int])
   : IndexedSeq[(String, Array[Float])] = {
     // iterating over the all the predictions
@@ -170,6 +177,18 @@ class ObjectDetector(modelPathPrefix: String,
     result
   }
 
+  /**
+    * Creates an image classifier from the object detector model
+    * @param modelPathPrefix    Path prefix from where to load the model artifacts.
+    *                           These include the symbol, parameters, and synset.txt.
+    *                           Example: file://model-dir/resnet-152 (containing
+    *                           resnet-152-symbol.json, resnet-152-0000.params, and synset.txt).
+    * @param inputDescriptors   Descriptors defining the input node names, shape,
+    *                           layout and type parameters
+    * @param contexts           Device contexts on which you want to run inference; defaults to CPU
+    * @param epoch              Model epoch to load; defaults to 0
+    * @return The corresponding image classifier
+    */
   private[infer] def getImageClassifier(modelPathPrefix: String,
                                         inputDescriptors: IndexedSeq[DataDesc],
                          contexts: Array[Context] = Context.cpu(),

scala-package/infer/src/main/scala/org/apache/mxnet/infer/Predictor.scala

@@ -33,27 +33,27 @@ import org.slf4j.LoggerFactory
 private[infer] trait PredictBase {
 
   /**
-   * Converts indexed sequences of 1-D array to NDArrays.
-   * <p>
-   * This method will take input as IndexedSeq one dimensional arrays and creates the
-   * NDArray needed for inference. The array will be reshaped based on the input descriptors.
-   * @param input:            An Indexed Sequence of a one-dimensional array of datatype
-    *                         Float or Double
-                              An IndexedSequence is needed when the model has more than one input.
-   * @return                  Indexed sequence array of outputs
-   */
+    * Converts indexed sequences of 1-D array to NDArrays.
+    * This method will take input as IndexedSeq one dimensional arrays and creates the
+    * NDArray needed for inference. The array will be reshaped based on the input descriptors.
+    * @tparam T The Scala equivalent of the DType used for the input array and return value
+    * @param input An Indexed Sequence of a one-dimensional array of datatype
+    *              Float or Double
+    *              An IndexedSequence is needed when the model has more than one input.
+    * @return      Indexed sequence array of outputs
+    */
   def predict[@specialized (Base.MX_PRIMITIVES) T](input: IndexedSeq[Array[T]])
   : IndexedSeq[Array[T]]
 
   /**
-   * Predict using NDArray as input.
-   * <p>
-   * This method is useful when the input is a batch of data
-   * or when multiple operations on the input have to performed.
-   * Note: User is responsible for managing allocation/deallocation of NDArrays.
-   * @param input             IndexedSequence NDArrays.
-   * @return                  Output of predictions as NDArrays.
-   */
+    * Predict using NDArray as input.
+    * <p>
+    * This method is useful when the input is a batch of data
+    * or when multiple operations on the input have to performed.
+    * Note: User is responsible for managing allocation/deallocation of NDArrays.
+    * @param input             IndexedSequence NDArrays.
+    * @return                  Output of predictions as NDArrays.
+    */
   def predictWithNDArray(input: IndexedSeq[NDArray]): IndexedSeq[NDArray]
 
   /**
@@ -248,6 +248,10 @@ class Predictor(modelPathPrefix: String,
     resultND
   }
 
+  /**
+    * Creates the module backing the Predictor with the same path, epoch, contexts, and inputs
+    * @return The Module
+    */
   private[infer] def loadModule(): Module = {
     val mod = mxNetHandler.execute(Module.loadCheckpoint(modelPathPrefix, epoch.get,
       contexts = contexts, dataNames = inputDescriptors.map(desc => desc.name)))

scala-package/infer/src/main/scala/org/apache/mxnet/infer/javaapi/ObjectDetector.scala

@@ -31,19 +31,23 @@ import scala.language.implicitConversions
   * The ObjectDetector class helps to run ObjectDetection tasks where the goal
   * is to find bounding boxes and corresponding labels for objects in a image.
   *
-  * @param modelPathPrefix    Path prefix from where to load the model artifacts.
-  *                           These include the symbol, parameters, and synset.txt.
-  *                           Example: file://model-dir/ssd_resnet50_512 (containing
-  *                           ssd_resnet50_512-symbol.json, ssd_resnet50_512-0000.params,
-  *                           and synset.txt)
-  * @param inputDescriptors   Descriptors defining the input node names, shape,
-  *                           layout and type parameters
-  * @param contexts           Device contexts on which you want to run inference.
-  *                           Defaults to CPU.
-  * @param epoch              Model epoch to load; defaults to 0
+  * @param objDetector A source Scala Object detector
   */
 class ObjectDetector private[mxnet] (val objDetector: org.apache.mxnet.infer.ObjectDetector){
 
+  /**
+    *
+    * @param modelPathPrefix    Path prefix from where to load the model artifacts.
+    *                           These include the symbol, parameters, and synset.txt.
+    *                           Example: file://model-dir/ssd_resnet50_512 (containing
+    *                           ssd_resnet50_512-symbol.json, ssd_resnet50_512-0000.params,
+    *                           and synset.txt)
+    * @param inputDescriptors   Descriptors defining the input node names, shape,
+    *                           layout and type parameters
+    * @param contexts           Device contexts on which you want to run inference.
+    *                           Defaults to CPU.
+    * @param epoch              Model epoch to load; defaults to 0
+    */
   def this(modelPathPrefix: String, inputDescriptors: java.lang.Iterable[DataDesc], contexts:
   java.lang.Iterable[Context], epoch: Int)
   = this {
@@ -98,32 +102,78 @@ class ObjectDetector private[mxnet] (val objDetector: org.apache.mxnet.infer.Obj
     (ret map {a => (a map {e => new ObjectDetectorOutput(e._1, e._2)}).asJava}).asJava
   }
 
+  /**
+    * Helper to map an implicit conversion
+    * @param l The value to convert
+    * @tparam B The desired type
+    * @tparam A The input type
+    * @return The converted result
+    */
   def convert[B, A <% B](l: IndexedSeq[A]): IndexedSeq[B] = l map { a => a: B }
 
 }
 
 
 object ObjectDetector {
-  implicit def fromObjectDetector(OD: org.apache.mxnet.infer.ObjectDetector):
-    ObjectDetector = new ObjectDetector(OD)
-
-  implicit def toObjectDetector(jOD: ObjectDetector):
-    org.apache.mxnet.infer.ObjectDetector = jOD.objDetector
 
+  /**
+    * Loads an input images from file
+    * @param inputImagePath   Path of single input image
+    * @return                 BufferedImage Buffered image
+    */
   def loadImageFromFile(inputImagePath: String): BufferedImage = {
     org.apache.mxnet.infer.ImageClassifier.loadImageFromFile(inputImagePath)
   }
 
+  /**
+    * Reshape the input image to a new shape
+    *
+    * @param img              Input image
+    * @param newWidth         New width for rescaling
+    * @param newHeight        New height for rescaling
+    * @return                 Rescaled BufferedImage
+    */
   def reshapeImage(img : BufferedImage, newWidth: Int, newHeight: Int): BufferedImage = {
     org.apache.mxnet.infer.ImageClassifier.reshapeImage(img, newWidth, newHeight)
   }
 
+  /**
+    * Convert input BufferedImage to NDArray of input shape
+    * Note: Caller is responsible to dispose the NDArray
+    * returned by this method after the use.
+    *
+    * @param resizedImage BufferedImage to get pixels from
+    * @param inputImageShape Input shape; for example for resnet it is (3,224,224).
+    *                        Should be same as inputDescriptor shape.
+    * @return NDArray pixels array with shape (3, 224, 224) in CHW format
+    */
   def bufferedImageToPixels(resizedImage: BufferedImage, inputImageShape: Shape): NDArray = {
     org.apache.mxnet.infer.ImageClassifier.bufferedImageToPixels(resizedImage, inputImageShape)
   }
 
+  /**
+    * Loads a batch of images from a folder
+    * @param inputImagePaths  Path to a folder of images
+    * @return                   List of buffered images
+    */
   def loadInputBatch(inputImagePaths: java.lang.Iterable[String]): java.util.List[BufferedImage] = {
     org.apache.mxnet.infer.ImageClassifier
       .loadInputBatch(inputImagePaths.asScala.toList).toList.asJava
   }
+
+  /**
+    * Implicitly convert a Scala ObjectDetector to a Java ObjectDetector
+    * @param OD The Scala ObjectDetector
+    * @return The Java ObjectDetector
+    */
+  implicit def fromObjectDetector(OD: org.apache.mxnet.infer.ObjectDetector):
+  ObjectDetector = new ObjectDetector(OD)
+
+  /**
+    * Implicitly converts a Java ObjectDetector to a Scala ObjectDetector
+    * @param jOD The Java ObjectDetector
+    * @return The Scala ObjectDetector
+    */
+  implicit def toObjectDetector(jOD: ObjectDetector):
+  org.apache.mxnet.infer.ObjectDetector = jOD.objDetector
 }