{"cells":[{"metadata":{},"cell_type":"markdown","source":"# Flower classification using TPUs\n\nIn this project we will classify the images of flowers to the corresponding species. There are 104 different flowers in total. First, I will visualise a subset of datasets, then I will move forward to the training and finally inference.\n\n* **Note: my analysis shows that integrating validation data to the training data will boost my performance on the leaderboard. However, there is definitely an obvious tradeoff between performance and overfitting. So make sure that you use early-stoppping when setting skipping the validation during the training.**\n\n## <a id='main'>Table of Contents</a>\n- [Exploring data](#exp)\n\n    1. [TPU config](#tpu)\n    2. [Data import & visualisation](#imvis)\n    \n    \n- [Training and Prediction](#tp)\n\n    1. [Data processing & augmentation](#aug)\n    2. [Training](#tr)\n    3. [Prediction](#pr)","execution_count":null},{"metadata":{},"cell_type":"markdown","source":"# <a id='exp'>Exploring data</a>","execution_count":null},{"metadata":{},"cell_type":"markdown","source":"Let's first install some dependencies ...","execution_count":null},{"metadata":{"_uuid":"d629ff2d2480ee46fbb7e2d37f6b5fab8052498a","_cell_guid":"79c7e3d0-c299-4dcb-8224-4455121ee9b0","trusted":true},"cell_type":"code","source":"# we will install efficientnet as this notebooki heavily depends on this network\n!pip install -q efficientnet","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"# we will install tensorflow_addons to utilise the metrics F1-score to monitor training\n!pip install tensorflow_addons","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"# Let's import essentials\n\nimport math, re, os\nimport tensorflow as tf\nimport numpy as np\nfrom matplotlib import pyplot as plt\nfrom kaggle_datasets import KaggleDatasets\nimport efficientnet.tfkeras as efn\nfrom sklearn.metrics import f1_score, precision_score, recall_score, confusion_matrix\nfrom tensorflow.keras.applications import InceptionResNetV2\nfrom tensorflow.keras.applications import DenseNet201\nfrom tensorflow.keras.preprocessing.image import ImageDataGenerator\nprint(\"Tensorflow version \" + tf.__version__)\nfrom tensorflow.keras import backend as K\nimport gc\nimport tensorflow_addons as tfa","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"### <a id='tpu'>TPU config</a>\nLet's detect TPU and return appropriate distribution strategy. Source from [starter kernel](https://www.kaggle.com/mgornergoogle/getting-started-with-100-flowers-on-tpu).\nNote: Make sure that you have enabled TPU as accelerator on your kernel ;)","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"# Detect hardware, return appropriate distribution strategy\ntry:\n    tpu = tf.distribute.cluster_resolver.TPUClusterResolver()  # TPU detection. No parameters necessary if TPU_NAME environment variable is set. On Kaggle this is always the case.\n    print('Running on TPU ', tpu.master())\nexcept ValueError:\n    tpu = None\n\nif tpu:\n    tf.config.experimental_connect_to_cluster(tpu)\n    tf.tpu.experimental.initialize_tpu_system(tpu)\n    strategy = tf.distribute.experimental.TPUStrategy(tpu)\nelse:\n    strategy = tf.distribute.get_strategy() # default distribution strategy in Tensorflow. Works on CPU and single GPU.\n\nprint(\"REPLICAS: \", strategy.num_replicas_in_sync)","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"### <a id='imvis'>Data import & visualisation</a>\nWe will now import the data and will set Kaggle bucket to read the data. Then we will visualise subsets of the data. Source from [starter kernel](https://www.kaggle.com/mgornergoogle/getting-started-with-100-flowers-on-tpu).","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"# Data access ...\nGCS_DS_PATH = KaggleDatasets().get_gcs_path('flower-classification-with-tpus')\n\n# configuration ...\nIMAGE_SIZE = [512, 512] # At this size, a GPU will run out of memory. Use the TPU.\n                        # For GPU training, please select 224 x 224 px image size.\nimg_size=512\nEPOCHS = 12\nBATCH_SIZE = 16 * strategy.num_replicas_in_sync\n\nGCS_PATH_SELECT = { # available image sizes\n    192: GCS_DS_PATH + '/tfrecords-jpeg-192x192',\n    224: GCS_DS_PATH + '/tfrecords-jpeg-224x224',\n    331: GCS_DS_PATH + '/tfrecords-jpeg-331x331',\n    512: GCS_DS_PATH + '/tfrecords-jpeg-512x512'\n}\nGCS_PATH = GCS_PATH_SELECT[IMAGE_SIZE[0]]\n\n# Filaments ...\nTRAINING_FILENAMES = tf.io.gfile.glob(GCS_PATH + '/train/*.tfrec')\nVALIDATION_FILENAMES = tf.io.gfile.glob(GCS_PATH + '/val/*.tfrec')\nTEST_FILENAMES = tf.io.gfile.glob(GCS_PATH + '/test/*.tfrec') # predictions on this dataset should be submitted for the competition","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"## IMPORTANT! \n\nNow it's time to determine the validation data. As I have highlighted above, my experience shows that including validation data as part of the training has boosted my performance. If you are going to set SKIP_VALIDATION to `True`, then be careful not to overfit! Use early stopping.\nMoreover, when I set the SKIP_VALIDATION to `False`, I will permute the validation data and incorporate ~50% of that in training dataset.\n\nIn this kernel I will set the SKIP_VALIDATION to `True`, as this kernel is for demonstration purpose only. Go ahead and happy fine tuning and exploration! ","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"# Here we determine the validation data ...\n\nSKIP_VALIDATION = True\nif SKIP_VALIDATION:\n    TRAINING_FILENAMES = TRAINING_FILENAMES + VALIDATION_FILENAMES\nelse:\n    import random\n    random.shuffle(VALIDATION_FILENAMES)\n    TRAINING_FILENAMES = TRAINING_FILENAMES + VALIDATION_FILENAMES[:len(VALIDATION_FILENAMES)//2]\n    VALIDATION_FILENAMES = VALIDATION_FILENAMES[len(VALIDATION_FILENAMES)//2:]","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"# Define the classes corresponding to 104 labels that we aim at classification\n\nCLASSES = ['pink primrose',    'hard-leaved pocket orchid', 'canterbury bells', 'sweet pea',     'wild geranium',     'tiger lily',           'moon orchid',              'bird of paradise', 'monkshood',        'globe thistle',         # 00 - 09\n           'snapdragon',       \"colt's foot\",               'king protea',      'spear thistle', 'yellow iris',       'globe-flower',         'purple coneflower',        'peruvian lily',    'balloon flower',   'giant white arum lily', # 10 - 19\n           'fire lily',        'pincushion flower',         'fritillary',       'red ginger',    'grape hyacinth',    'corn poppy',           'prince of wales feathers', 'stemless gentian', 'artichoke',        'sweet william',         # 20 - 29\n           'carnation',        'garden phlox',              'love in the mist', 'cosmos',        'alpine sea holly',  'ruby-lipped cattleya', 'cape flower',              'great masterwort', 'siam tulip',       'lenten rose',           # 30 - 39\n           'barberton daisy',  'daffodil',                  'sword lily',       'poinsettia',    'bolero deep blue',  'wallflower',           'marigold',                 'buttercup',        'daisy',            'common dandelion',      # 40 - 49\n           'petunia',          'wild pansy',                'primula',          'sunflower',     'lilac hibiscus',    'bishop of llandaff',   'gaura',                    'geranium',         'orange dahlia',    'pink-yellow dahlia',    # 50 - 59\n           'cautleya spicata', 'japanese anemone',          'black-eyed susan', 'silverbush',    'californian poppy', 'osteospermum',         'spring crocus',            'iris',             'windflower',       'tree poppy',            # 60 - 69\n           'gazania',          'azalea',                    'water lily',       'rose',          'thorn apple',       'morning glory',        'passion flower',           'lotus',            'toad lily',        'anthurium',             # 70 - 79\n           'frangipani',       'clematis',                  'hibiscus',         'columbine',     'desert-rose',       'tree mallow',          'magnolia',                 'cyclamen ',        'watercress',       'canna lily',            # 80 - 89\n           'hippeastrum ',     'bee balm',                  'pink quill',       'foxglove',      'bougainvillea',     'camellia',             'mallow',                   'mexican petunia',  'bromelia',         'blanket flower',        # 90 - 99\n           'trumpet creeper',  'blackberry lily',           'common tulip',     'wild rose']                                                                                                                                               # 100 - 102\n","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"Some helper functions to decode and visualise datasets. We will modify the decoding part later and I will discuss how and why.","execution_count":null},{"metadata":{},"cell_type":"markdown","source":"### Visualisation helpers","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"# numpy and matplotlib defaults\nnp.set_printoptions(threshold=15, linewidth=80)\n\ndef batch_to_numpy_images_and_labels(data):\n    images, labels = data\n    numpy_images = images.numpy()\n    numpy_labels = labels.numpy()\n    if numpy_labels.dtype == object: # binary string in this case, these are image ID strings\n        numpy_labels = [None for _ in enumerate(numpy_images)]\n    # If no labels, only image IDs, return None for labels (this is the case for test data)\n    return numpy_images, numpy_labels\n\ndef title_from_label_and_target(label, correct_label):\n    if correct_label is None:\n        return CLASSES[label], True\n    correct = (label == correct_label)\n    return \"{} [{}{}{}]\".format(CLASSES[label], 'OK' if correct else 'NO', u\"\\u2192\" if not correct else '',\n                                CLASSES[correct_label] if not correct else ''), correct\n\ndef display_one_flower(image, title, subplot, red=False, titlesize=16):\n    plt.subplot(*subplot)\n    plt.axis('off')\n    plt.imshow(image)\n    if len(title) > 0:\n        plt.title(title, fontsize=int(titlesize) if not red else int(titlesize/1.2), color='red' if red else 'black', fontdict={'verticalalignment':'center'}, pad=int(titlesize/1.5))\n    return (subplot[0], subplot[1], subplot[2]+1)\n    \ndef display_batch_of_images(databatch, predictions=None):\n    \"\"\"This will work with:\n    display_batch_of_images(images)\n    display_batch_of_images(images, predictions)\n    display_batch_of_images((images, labels))\n    display_batch_of_images((images, labels), predictions)\n    \"\"\"\n    # data\n    images, labels = batch_to_numpy_images_and_labels(databatch)\n    if labels is None:\n        labels = [None for _ in enumerate(images)]\n        \n    # auto-squaring: this will drop data that does not fit into square or square-ish rectangle\n    rows = int(math.sqrt(len(images)))\n    cols = len(images)//rows\n        \n    # size and spacing\n    FIGSIZE = 13.0\n    SPACING = 0.1\n    subplot=(rows,cols,1)\n    if rows < cols:\n        plt.figure(figsize=(FIGSIZE,FIGSIZE/cols*rows))\n    else:\n        plt.figure(figsize=(FIGSIZE/rows*cols,FIGSIZE))\n    \n    # display\n    for i, (image, label) in enumerate(zip(images[:rows*cols], labels[:rows*cols])):\n        title = '' if label is None else CLASSES[label]\n        correct = True\n        if predictions is not None:\n            title, correct = title_from_label_and_target(predictions[i], label)\n        dynamic_titlesize = FIGSIZE*SPACING/max(rows,cols)*40+3 # magic formula tested to work from 1x1 to 10x10 images\n        subplot = display_one_flower(image, title, subplot, not correct, titlesize=dynamic_titlesize)\n    \n    #layout\n    plt.tight_layout()\n    if label is None and predictions is None:\n        plt.subplots_adjust(wspace=0, hspace=0)\n    else:\n        plt.subplots_adjust(wspace=SPACING, hspace=SPACING)\n    plt.show()\n\ndef display_confusion_matrix(cmat, score, precision, recall):\n    plt.figure(figsize=(15,15))\n    ax = plt.gca()\n    ax.matshow(cmat, cmap='Reds')\n    ax.set_xticks(range(len(CLASSES)))\n    ax.set_xticklabels(CLASSES, fontdict={'fontsize': 7})\n    plt.setp(ax.get_xticklabels(), rotation=45, ha=\"left\", rotation_mode=\"anchor\")\n    ax.set_yticks(range(len(CLASSES)))\n    ax.set_yticklabels(CLASSES, fontdict={'fontsize': 7})\n    plt.setp(ax.get_yticklabels(), rotation=45, ha=\"right\", rotation_mode=\"anchor\")\n    titlestring = \"\"\n    if score is not None:\n        titlestring += 'f1 = {:.3f} '.format(score)\n    if precision is not None:\n        titlestring += '\\nprecision = {:.3f} '.format(precision)\n    if recall is not None:\n        titlestring += '\\nrecall = {:.3f} '.format(recall)\n    if len(titlestring) > 0:\n        ax.text(101, 1, titlestring, fontdict={'fontsize': 18, 'horizontalalignment':'right', 'verticalalignment':'top', 'color':'#804040'})\n    plt.show()\n    \ndef display_training_curves(training, validation, title, subplot):\n    if subplot%10==1: # set up the subplots on the first call\n        plt.subplots(figsize=(10,10), facecolor='#F0F0F0')\n        plt.tight_layout()\n    ax = plt.subplot(subplot)\n    ax.set_facecolor('#F8F8F8')\n    ax.plot(training)\n    ax.plot(validation)\n    ax.set_title('model '+ title)\n    ax.set_ylabel(title)\n    #ax.set_ylim(0.28,1.05)\n    ax.set_xlabel('epoch')\n    ax.legend(['train', 'valid.'])","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"### Dataset helpers","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"def decode_image(image_data):\n    image = tf.image.decode_jpeg(image_data, channels=3)\n    image = tf.cast(image, tf.float32) / 255.0  # convert image to floats in [0, 1] range\n    image = tf.reshape(image, [*IMAGE_SIZE, 3]) # explicit size needed for TPU\n    return image\n\ndef read_labeled_tfrecord(example):\n    LABELED_TFREC_FORMAT = {\n        \"image\": tf.io.FixedLenFeature([], tf.string), # tf.string means bytestring\n        \"class\": tf.io.FixedLenFeature([], tf.int64),  # shape [] means single element\n    }\n    example = tf.io.parse_single_example(example, LABELED_TFREC_FORMAT)\n    image = decode_image(example['image'])\n    label = tf.cast(example['class'], tf.int32)\n    return image, label # returns a dataset of (image, label) pairs\n\ndef read_unlabeled_tfrecord(example):\n    UNLABELED_TFREC_FORMAT = {\n        \"image\": tf.io.FixedLenFeature([], tf.string), # tf.string means bytestring\n        \"id\": tf.io.FixedLenFeature([], tf.string),  # shape [] means single element\n        # class is missing, this competitions's challenge is to predict flower classes for the test dataset\n    }\n    example = tf.io.parse_single_example(example, UNLABELED_TFREC_FORMAT)\n    image = decode_image(example['image'])\n    idnum = example['id']\n    return image, idnum # returns a dataset of image(s)\n\ndef load_dataset(filenames, labeled=True, ordered=False):\n    # Read from TFRecords. For optimal performance, reading from multiple files at once and\n    # disregarding data order. Order does not matter since we will be shuffling the data anyway.\n\n    ignore_order = tf.data.Options()\n    if not ordered:\n        ignore_order.experimental_deterministic = False # disable order, increase speed\n\n    dataset = tf.data.TFRecordDataset(filenames, num_parallel_reads=AUTO) # automatically interleaves reads from multiple files\n    dataset = dataset.with_options(ignore_order) # uses data as soon as it streams in, rather than in its original order\n    dataset = dataset.map(read_labeled_tfrecord if labeled else read_unlabeled_tfrecord, num_parallel_calls=AUTO)\n    # returns a dataset of (image, label) pairs if labeled=True or (image, id) pairs if labeled=False\n    return dataset\n\ndef data_augment(image, label):\n    # data augmentation. Thanks to the dataset.prefetch(AUTO) statement in the next function (below),\n    # this happens essentially for free on TPU. Data pipeline code is executed on the \"CPU\" part\n    # of the TPU while the TPU itself is computing gradients.\n    image = tf.image.random_flip_left_right(image)\n    #image = tf.image.random_saturation(image, 0, 2)\n    return image, label   \n\ndef get_training_dataset():\n    dataset = load_dataset(TRAINING_FILENAMES, labeled=True)\n    dataset = dataset.map(data_augment, num_parallel_calls=AUTO)\n    dataset = dataset.repeat() # the training dataset must repeat for several epochs\n    dataset = dataset.shuffle(2048)\n    dataset = dataset.batch(BATCH_SIZE)\n    dataset = dataset.prefetch(AUTO) # prefetch next batch while training (autotune prefetch buffer size)\n    return dataset\n\ndef get_validation_dataset(ordered=False):\n    dataset = load_dataset(VALIDATION_FILENAMES, labeled=True, ordered=ordered)\n    dataset = dataset.batch(BATCH_SIZE)\n    dataset = dataset.cache()\n    dataset = dataset.prefetch(AUTO) # prefetch next batch while training (autotune prefetch buffer size)\n    return dataset\n\ndef get_test_dataset(ordered=False):\n    dataset = load_dataset(TEST_FILENAMES, labeled=False, ordered=ordered)\n    dataset = dataset.batch(BATCH_SIZE)\n    dataset = dataset.prefetch(AUTO) # prefetch next batch while training (autotune prefetch buffer size)\n    return dataset\n\ndef count_data_items(filenames):\n    # the number of data items is written in the name of the .tfrec files, i.e. flowers00-230.tfrec = 230 data items\n    n = [int(re.compile(r\"-([0-9]*)\\.\").search(filename).group(1)) for filename in filenames]\n    return np.sum(n)\n\nNUM_TRAINING_IMAGES = count_data_items(TRAINING_FILENAMES)\nNUM_VALIDATION_IMAGES = count_data_items(VALIDATION_FILENAMES)\nNUM_TEST_IMAGES = count_data_items(TEST_FILENAMES)\nSTEPS_PER_EPOCH = NUM_TRAINING_IMAGES // BATCH_SIZE\nprint('Dataset: {} training images, {} validation images, {} unlabeled test images'.format(NUM_TRAINING_IMAGES, NUM_VALIDATION_IMAGES, NUM_TEST_IMAGES))\n","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"## Data visualisation","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"AUTO = tf.data.experimental.AUTOTUNE","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"# data dump\nprint(\"Training data shapes:\")\nfor image, label in get_training_dataset().take(3):\n    print(image.numpy().shape, label.numpy().shape)\nprint(\"Training data label examples:\", label.numpy())\nprint(\"Validation data shapes:\")\nfor image, label in get_validation_dataset().take(3):\n    print(image.numpy().shape, label.numpy().shape)\nprint(\"Validation data label examples:\", label.numpy())\nprint(\"Test data shapes:\")\nfor image, idnum in get_test_dataset().take(3):\n    print(image.numpy().shape, idnum.numpy().shape)\nprint(\"Test data IDs:\", idnum.numpy().astype('U')) # U=unicode string","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"# Peek at training data\ntraining_dataset = get_training_dataset()\ntraining_dataset = training_dataset.unbatch().batch(40) # let's visualise sample 40 images of the training\ntrain_batch = iter(training_dataset)","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"# run this cell again for next set of images\ndisplay_batch_of_images(next(train_batch))","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"# Peek at test data\ntest_dataset = get_test_dataset()\ntest_dataset = test_dataset.unbatch().batch(40) # let's visualise sample 40 images of the testing\ntest_batch = iter(test_dataset)","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"# run this cell again for next set of images\ndisplay_batch_of_images(next(test_batch))","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"# <a id='tp'>Training and Prediction</a>","execution_count":null},{"metadata":{},"cell_type":"markdown","source":"We are going to use categorical focal loss function ([This paper](https://arxiv.org/pdf/1708.02002.pdf)) in this kernel hence we will need to modify data helpers slightly as we have defined earlier in the above. You might ask why doing this again, well this is maninly because that I didn't want to ruin the labels as in the new setting we will encode the data as one_hot encoded labels to conform the loss function that we want to use. See the below for more details.","execution_count":null},{"metadata":{},"cell_type":"markdown","source":"### <a id='aug'>Data processing & augmentation</a>\nI am going to skip the data augmentation here in this kernel. If you wish to use it (as you should!), uncomment the commented line in the `get_training_dataset` block below.","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"# let's define helpers again tu suit one_hot encoded labels\n\ndef decode_image(image_data):\n    image = tf.image.decode_jpeg(image_data, channels=3)\n    image = tf.cast(image, tf.float32) / 255.0  # convert image to floats in [0, 1] range\n    image = tf.reshape(image, [*IMAGE_SIZE, 3]) # explicit size needed for TPU\n    return image\n\ndef read_labeled_tfrecord(example):\n    LABELED_TFREC_FORMAT = {\n        \"image\": tf.io.FixedLenFeature([], tf.string), # tf.string means bytestring\n        \"class\": tf.io.FixedLenFeature([], tf.int64),  # shape [] means single element\n    }\n    example = tf.io.parse_single_example(example, LABELED_TFREC_FORMAT)\n    image = decode_image(example['image'])\n    label = tf.one_hot(example['class'], 104)\n    return image, label # returns a dataset of (image, label) pairs\n\ndef read_labeled_tfrecord_train(example):\n    LABELED_TFREC_FORMAT = {\n        \"image\": tf.io.FixedLenFeature([], tf.string), # tf.string means bytestring\n        \"class\": tf.io.FixedLenFeature([], tf.int64),  # shape [] means single element\n    }\n    example = tf.io.parse_single_example(example, LABELED_TFREC_FORMAT)\n    image = decode_image(example['image'])\n    label = tf.one_hot(example['class'], 104)\n    return image, label # returns a dataset of (image, label) pairs\n\ndef read_unlabeled_tfrecord(example):\n    UNLABELED_TFREC_FORMAT = {\n        \"image\": tf.io.FixedLenFeature([], tf.string), # tf.string means bytestring\n        \"id\": tf.io.FixedLenFeature([], tf.string),  # shape [] means single element\n        # class is missing, this competitions's challenge is to predict flower classes for the test dataset\n    }\n    example = tf.io.parse_single_example(example, UNLABELED_TFREC_FORMAT)\n    image = decode_image(example['image'])\n    idnum = example['id']\n    return image, idnum # returns a dataset of image(s)\n\ndef load_dataset(filenames, labeled=True, ordered=False):\n    ignore_order = tf.data.Options()\n    if not ordered:\n        ignore_order.experimental_deterministic = False\n    dataset = tf.data.TFRecordDataset(filenames, num_parallel_reads=AUTO) \n    dataset = dataset.with_options(ignore_order) \n    dataset = dataset.map(read_labeled_tfrecord if labeled else read_unlabeled_tfrecord, num_parallel_calls=AUTO)\n    return dataset\n\ndef load_dataset_train(filenames, labeled=True, ordered=False):\n    # Read from TFRecords. For optimal performance, reading from multiple files at once and\n    # disregarding data order. Order does not matter since we will be shuffling the data anyway.\n\n    ignore_order = tf.data.Options()\n    if not ordered:\n        ignore_order.experimental_deterministic = False # disable order, increase speed\n\n    dataset = tf.data.TFRecordDataset(filenames, num_parallel_reads=AUTO) # automatically interleaves reads from multiple files\n    dataset = dataset.with_options(ignore_order) # uses data as soon as it streams in, rather than in its original order\n    dataset = dataset.map(read_labeled_tfrecord_train if labeled else read_unlabeled_tfrecord, num_parallel_calls=AUTO)\n    # returns a dataset of (image, label) pairs if labeled=True or (image, id) pairs if labeled=False\n    return dataset\n\n# I will skip augmentation here in this kernel. If you wish to use augmentation, uncomment the \"if\" line\n# in the following block\ndef get_training_dataset(do_aug=False):\n    dataset = load_dataset_train(TRAINING_FILENAMES, labeled=True)\n    dataset = dataset.map(data_augment, num_parallel_calls=AUTO)\n#     if do_aug: dataset = dataset.map(transform, num_parallel_calls=AUTO)\n    dataset = dataset.repeat() # the training dataset must repeat for several epochs\n    dataset = dataset.shuffle(2048)\n    dataset = dataset.batch(BATCH_SIZE)\n    dataset = dataset.prefetch(AUTO) # prefetch next batch while training (autotune prefetch buffer size)\n    return dataset\n\n\n\ndef data_augment(image, label):\n    # data augmentation. Thanks to the dataset.prefetch(AUTO) statement in the next function (below),\n    # this happens essentially for free on TPU. Data pipeline code is executed on the \"CPU\" part\n    # of the TPU while the TPU itself is computing gradients.\n    # Just randomly flipping images to the right and left here\n    image = tf.image.random_flip_left_right(image)\n    return image, label   \n\ndef get_validation_dataset(ordered=False):\n    dataset = load_dataset(VALIDATION_FILENAMES, labeled=True, ordered=ordered)\n    dataset = dataset.batch(BATCH_SIZE)\n    dataset = dataset.cache()\n    dataset = dataset.prefetch(AUTO) # prefetch next batch while training (autotune prefetch buffer size)\n    return dataset\n\ndef get_test_dataset(ordered=False):\n    dataset = load_dataset(TEST_FILENAMES, labeled=False, ordered=ordered)\n    dataset = dataset.batch(BATCH_SIZE)\n    dataset = dataset.prefetch(AUTO)\n    return dataset\n\ndef count_data_items(filenames):\n    # the number of data items is written in the name of the .tfrec files, i.e. flowers00-230.tfrec = 230 data items\n    n = [int(re.compile(r\"-([0-9]*)\\.\").search(filename).group(1)) for filename in filenames]\n    return np.sum(n)\n\nNUM_TRAINING_IMAGES = count_data_items(TRAINING_FILENAMES)\nNUM_VALIDATION_IMAGES = (1 - SKIP_VALIDATION) * count_data_items(VALIDATION_FILENAMES)\nNUM_TEST_IMAGES = count_data_items(TEST_FILENAMES)\nSTEPS_PER_EPOCH = NUM_TRAINING_IMAGES // BATCH_SIZE\nprint('Dataset: {} training images, {} validation images, {} unlabeled test images'.format(NUM_TRAINING_IMAGES, NUM_VALIDATION_IMAGES, NUM_TEST_IMAGES))\n","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"## Data augmentation\n\nData augmentation is necessary for any CV task including classification. I have used the following helpers from [this notebook](https://www.kaggle.com/cdeotte/rotation-augmentation-gpu-tpu-0-96#Data-Augmentation-using-GPU/TPU-for-Maximum-Speed!) to augment the images and steamline along with the TPU strategy.","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"def get_mat(rotation, shear, height_zoom, width_zoom, height_shift, width_shift):\n    # returns 3x3 transformmatrix which transforms indicies\n        \n    # CONVERT DEGREES TO RADIANS\n    rotation = math.pi * rotation / 180.\n    shear = math.pi * shear / 180.\n    \n    # ROTATION MATRIX\n    c1 = tf.math.cos(rotation)\n    s1 = tf.math.sin(rotation)\n    one = tf.constant([1],dtype='float32')\n    zero = tf.constant([0],dtype='float32')\n    rotation_matrix = tf.reshape( tf.concat([c1,s1,zero, -s1,c1,zero, zero,zero,one],axis=0),[3,3] )\n        \n    # SHEAR MATRIX\n    c2 = tf.math.cos(shear)\n    s2 = tf.math.sin(shear)\n    shear_matrix = tf.reshape( tf.concat([one,s2,zero, zero,c2,zero, zero,zero,one],axis=0),[3,3] )    \n    \n    # ZOOM MATRIX\n    zoom_matrix = tf.reshape( tf.concat([one/height_zoom,zero,zero, zero,one/width_zoom,zero, zero,zero,one],axis=0),[3,3] )\n    \n    # SHIFT MATRIX\n    shift_matrix = tf.reshape( tf.concat([one,zero,height_shift, zero,one,width_shift, zero,zero,one],axis=0),[3,3] )\n    \n    return K.dot(K.dot(rotation_matrix, shear_matrix), K.dot(zoom_matrix, shift_matrix))","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"def transform(image,label):\n    # input image - is one image of size [dim,dim,3] not a batch of [b,dim,dim,3]\n    # output - image randomly rotated, sheared, zoomed, and shifted\n    DIM = IMAGE_SIZE[0]\n    XDIM = DIM%2 #fix for size 331\n    \n    rot = 15. * tf.random.normal([1],dtype='float32')\n    shr = 5. * tf.random.normal([1],dtype='float32') \n    h_zoom = 1.0 + tf.random.normal([1],dtype='float32')/10.\n    w_zoom = 1.0 + tf.random.normal([1],dtype='float32')/10.\n    h_shift = 16. * tf.random.normal([1],dtype='float32') \n    w_shift = 16. * tf.random.normal([1],dtype='float32') \n  \n    # GET TRANSFORMATION MATRIX\n    m = get_mat(rot,shr,h_zoom,w_zoom,h_shift,w_shift) \n\n    # LIST DESTINATION PIXEL INDICES\n    x = tf.repeat( tf.range(DIM//2,-DIM//2,-1), DIM )\n    y = tf.tile( tf.range(-DIM//2,DIM//2),[DIM] )\n    z = tf.ones([DIM*DIM],dtype='int32')\n    idx = tf.stack( [x,y,z] )\n    \n    # ROTATE DESTINATION PIXELS ONTO ORIGIN PIXELS\n    idx2 = K.dot(m,tf.cast(idx,dtype='float32'))\n    idx2 = K.cast(idx2,dtype='int32')\n    idx2 = K.clip(idx2,-DIM//2+XDIM+1,DIM//2)\n    \n    # FIND ORIGIN PIXEL VALUES           \n    idx3 = tf.stack( [DIM//2-idx2[0,], DIM//2-1+idx2[1,]] )\n    d = tf.gather_nd(image,tf.transpose(idx3))\n        \n    return tf.reshape(d,[DIM,DIM,3]),label","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"### <a id='tr'>Training</a>\nI am going to skip the data augmentation here in this kernel. If you wish to use it (as you should!), uncomment the commented line in the `get_training_dataset` block below.","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"def decode_image(image_data):\n    image = tf.image.decode_jpeg(image_data, channels=3)\n    image = tf.cast(image, tf.float32) / 255.0  # convert image to floats in [0, 1] range\n    image = tf.reshape(image, [*IMAGE_SIZE, 3]) # explicit size needed for TPU\n    return image\n\ndef read_labeled_tfrecord(example):\n    LABELED_TFREC_FORMAT = {\n        \"image\": tf.io.FixedLenFeature([], tf.string), # tf.string means bytestring\n        \"class\": tf.io.FixedLenFeature([], tf.int64),  # shape [] means single element\n    }\n    example = tf.io.parse_single_example(example, LABELED_TFREC_FORMAT)\n    image = decode_image(example['image'])\n    label = tf.one_hot(example['class'], 104)\n#     label = tf.cast(example['class'], tf.int32)\n    return image, label # returns a dataset of (image, label) pairs\n\ndef read_labeled_tfrecord_train(example):\n    LABELED_TFREC_FORMAT = {\n        \"image\": tf.io.FixedLenFeature([], tf.string), # tf.string means bytestring\n        \"class\": tf.io.FixedLenFeature([], tf.int64),  # shape [] means single element\n    }\n    example = tf.io.parse_single_example(example, LABELED_TFREC_FORMAT)\n    image = decode_image(example['image'])\n    label = tf.one_hot(example['class'], 104)\n#     label = tf.cast(example['class'], tf.int32)\n    return image, label # returns a dataset of (image, label) pairs\n\ndef read_unlabeled_tfrecord(example):\n    UNLABELED_TFREC_FORMAT = {\n        \"image\": tf.io.FixedLenFeature([], tf.string), # tf.string means bytestring\n        \"id\": tf.io.FixedLenFeature([], tf.string),  # shape [] means single element\n        # class is missing, this competitions's challenge is to predict flower classes for the test dataset\n    }\n    example = tf.io.parse_single_example(example, UNLABELED_TFREC_FORMAT)\n    image = decode_image(example['image'])\n    idnum = example['id']\n    return image, idnum # returns a dataset of image(s)\n\ndef load_dataset(filenames, labeled=True, ordered=False):\n    ignore_order = tf.data.Options()\n    if not ordered:\n        ignore_order.experimental_deterministic = False\n    dataset = tf.data.TFRecordDataset(filenames, num_parallel_reads=AUTO) \n    dataset = dataset.with_options(ignore_order) \n    dataset = dataset.map(read_labeled_tfrecord if labeled else read_unlabeled_tfrecord, num_parallel_calls=AUTO)\n    return dataset\n\ndef load_dataset_train(filenames, labeled=True, ordered=False):\n    # Read from TFRecords. For optimal performance, reading from multiple files at once and\n    # disregarding data order. Order does not matter since we will be shuffling the data anyway.\n\n    ignore_order = tf.data.Options()\n    if not ordered:\n        ignore_order.experimental_deterministic = False # disable order, increase speed\n\n    dataset = tf.data.TFRecordDataset(filenames, num_parallel_reads=AUTO) # automatically interleaves reads from multiple files\n    dataset = dataset.with_options(ignore_order) # uses data as soon as it streams in, rather than in its original order\n    dataset = dataset.map(read_labeled_tfrecord_train if labeled else read_unlabeled_tfrecord, num_parallel_calls=AUTO)\n    # returns a dataset of (image, label) pairs if labeled=True or (image, id) pairs if labeled=False\n    return dataset\n\ndef get_training_dataset(do_aug=False):\n    dataset = load_dataset_train(TRAINING_FILENAMES, labeled=True)\n    dataset = dataset.map(data_augment, num_parallel_calls=AUTO)\n    if do_aug: dataset = dataset.map(transform, num_parallel_calls=AUTO)\n    dataset = dataset.repeat() # the training dataset must repeat for several epochs\n    dataset = dataset.shuffle(2048)\n    dataset = dataset.batch(BATCH_SIZE)\n    dataset = dataset.prefetch(AUTO) # prefetch next batch while training (autotune prefetch buffer size)\n    return dataset\n\n\n\ndef data_augment(image, label):\n    # data augmentation. Thanks to the dataset.prefetch(AUTO) statement in the next function (below),\n    # this happens essentially for free on TPU. Data pipeline code is executed on the \"CPU\" part\n    # of the TPU while the TPU itself is computing gradients.\n    image = tf.image.random_flip_left_right(image)\n    return image, label   \n\n# def get_training_dataset():\n#     dataset = load_dataset(TRAINING_FILENAMES, labeled=True)\n#     dataset = dataset.map(data_augment, num_parallel_calls=AUTO)\n#     dataset = dataset.repeat() # the training dataset must repeat for several epochs\n#     dataset = dataset.shuffle(2048)\n#     dataset = dataset.batch(BATCH_SIZE)\n#     dataset = dataset.prefetch(AUTO) # prefetch next batch while training (autotune prefetch buffer size)\n#     return dataset\n\ndef get_validation_dataset(ordered=False):\n    dataset = load_dataset(VALIDATION_FILENAMES, labeled=True, ordered=ordered)\n    dataset = dataset.batch(BATCH_SIZE)\n    dataset = dataset.cache()\n    dataset = dataset.prefetch(AUTO) # prefetch next batch while training (autotune prefetch buffer size)\n    return dataset\n\ndef get_test_dataset(ordered=False):\n    dataset = load_dataset(TEST_FILENAMES, labeled=False, ordered=ordered)\n    dataset = dataset.batch(BATCH_SIZE)\n    dataset = dataset.prefetch(AUTO)\n    return dataset\n\ndef count_data_items(filenames):\n    # the number of data items is written in the name of the .tfrec files, i.e. flowers00-230.tfrec = 230 data items\n    n = [int(re.compile(r\"-([0-9]*)\\.\").search(filename).group(1)) for filename in filenames]\n    return np.sum(n)\n\nNUM_TRAINING_IMAGES = count_data_items(TRAINING_FILENAMES)\nNUM_VALIDATION_IMAGES = (1 - SKIP_VALIDATION) * count_data_items(VALIDATION_FILENAMES)\nNUM_TEST_IMAGES = count_data_items(TEST_FILENAMES)\nSTEPS_PER_EPOCH = NUM_TRAINING_IMAGES // BATCH_SIZE\nprint('Dataset: {} training images, {} validation images, {} unlabeled test images'.format(NUM_TRAINING_IMAGES, NUM_VALIDATION_IMAGES, NUM_TEST_IMAGES))\n","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"from tensorflow.keras import backend as K\n\nimport dill\n\n\ndef binary_focal_loss(gamma=2., alpha=.25):\n    \"\"\"\n    Binary form of focal loss.\n      FL(p_t) = -alpha * (1 - p_t)**gamma * log(p_t)\n      where p = sigmoid(x), p_t = p or 1 - p depending on if the label is 1 or 0, respectively.\n    References:\n        https://arxiv.org/pdf/1708.02002.pdf\n    Usage:\n     model.compile(loss=[binary_focal_loss(alpha=.25, gamma=2)], metrics=[\"accuracy\"], optimizer=adam)\n    \"\"\"\n    def binary_focal_loss_fixed(y_true, y_pred):\n        \"\"\"\n        :param y_true: A tensor of the same shape as `y_pred`\n        :param y_pred:  A tensor resulting from a sigmoid\n        :return: Output tensor.\n        \"\"\"\n        pt_1 = tf.where(tf.equal(y_true, 1), y_pred, tf.ones_like(y_pred))\n        pt_0 = tf.where(tf.equal(y_true, 0), y_pred, tf.zeros_like(y_pred))\n\n        epsilon = K.epsilon()\n        # clip to prevent NaN's and Inf's\n        pt_1 = K.clip(pt_1, epsilon, 1. - epsilon)\n        pt_0 = K.clip(pt_0, epsilon, 1. - epsilon)\n\n        return -K.sum(alpha * K.pow(1. - pt_1, gamma) * K.log(pt_1)) \\\n               -K.sum((1 - alpha) * K.pow(pt_0, gamma) * K.log(1. - pt_0))\n\n    return binary_focal_loss_fixed\n\n\ndef categorical_focal_loss(gamma=2., alpha=.25):\n    \"\"\"\n    Softmax version of focal loss.\n           m\n      FL = ∑  -alpha * (1 - p_o,c)^gamma * y_o,c * log(p_o,c)\n          c=1\n      where m = number of classes, c = class and o = observation\n    Parameters:\n      alpha -- the same as weighing factor in balanced cross entropy\n      gamma -- focusing parameter for modulating factor (1-p)\n    Default value:\n      gamma -- 2.0 as mentioned in the paper\n      alpha -- 0.25 as mentioned in the paper\n    References:\n        Official paper: https://arxiv.org/pdf/1708.02002.pdf\n        https://www.tensorflow.org/api_docs/python/tf/keras/backend/categorical_crossentropy\n    Usage:\n     model.compile(loss=[categorical_focal_loss(alpha=.25, gamma=2)], metrics=[\"accuracy\"], optimizer=adam)\n    \"\"\"\n    def categorical_focal_loss_fixed(y_true, y_pred):\n        \"\"\"\n        :param y_true: A tensor of the same shape as `y_pred`\n        :param y_pred: A tensor resulting from a softmax\n        :return: Output tensor.\n        \"\"\"\n\n        # Scale predictions so that the class probas of each sample sum to 1\n        y_pred /= K.sum(y_pred, axis=-1, keepdims=True)\n\n        # Clip the prediction value to prevent NaN's and Inf's\n        epsilon = K.epsilon()\n        y_pred = K.clip(y_pred, epsilon, 1. - epsilon)\n\n        # Calculate Cross Entropy\n        cross_entropy = -y_true * K.log(y_pred)\n\n        # Calculate Focal Loss\n        loss = alpha * K.pow(1 - y_pred, gamma) * cross_entropy\n\n        # Sum the losses in mini_batch\n        return K.sum(loss, axis=1)\n\n    return categorical_focal_loss_fixed\n","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"# Learning rate schedule for TPU, GPU and CPU.\n# Using an LR ramp up because fine-tuning a pre-trained model.\n# Starting with a high LR would break the pre-trained weights.\n\nLR_START = 0.00001\nLR_MAX = 0.00005 * strategy.num_replicas_in_sync\nLR_MIN = 0.00001\nLR_RAMPUP_EPOCHS = 4\nLR_SUSTAIN_EPOCHS = 4\nLR_EXP_DECAY = .8\n\ndef lrfn(epoch):\n    if epoch < LR_RAMPUP_EPOCHS:\n        lr = (LR_MAX - LR_START) / LR_RAMPUP_EPOCHS * epoch + LR_START\n    elif epoch < LR_RAMPUP_EPOCHS + LR_SUSTAIN_EPOCHS:\n        lr = LR_MAX\n    else:\n        lr = (LR_MAX - LR_MIN) * LR_EXP_DECAY**(epoch - LR_RAMPUP_EPOCHS - LR_SUSTAIN_EPOCHS) + LR_MIN\n    return lr\n    \nlr_callback = tf.keras.callbacks.LearningRateScheduler(lrfn, verbose = True)","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"with strategy.scope():\n    desnet=tf.keras.applications.DenseNet201(\n        weights='imagenet',\n        include_top=False\n      \n    )\n    model1 = tf.keras.Sequential([\n        desnet,\n        tf.keras.layers.GlobalAveragePooling2D(),\n        tf.keras.layers.Dense(len(CLASSES), activation='softmax')\n    ]) \n\nmodel1.compile(\n    optimizer=tf.keras.optimizers.Adam(lr=0.0001),\n    loss = [categorical_focal_loss(gamma=2., alpha=.25)],\n    metrics=[tfa.metrics.F1Score(num_classes=104, average=\"macro\")]\n)\nmodel1.summary()\nmodel1.load_weights('../input/mytopmodel/weights_dense_22.h5')","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"with strategy.scope():\n    enet = efn.EfficientNetB4(\n        input_shape=(img_size, img_size, 3),\n        weights='noisy-student',\n        include_top=False\n    )\n\n    model2 = tf.keras.Sequential([\n        enet,\n        tf.keras.layers.GlobalAveragePooling2D(),\n        tf.keras.layers.Dense(len(CLASSES), activation='softmax')\n    ]) \n\nmodel2.compile(\n    optimizer=tf.keras.optimizers.Adam(lr=0.0001),\n    loss = [categorical_focal_loss(gamma=2., alpha=.25)],\n    metrics=[tfa.metrics.F1Score(num_classes=104, average=\"macro\")]\n)\nmodel2.summary()\nmodel2.load_weights('../input/mytopmodel/weights_efficient_20.h5')","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"with strategy.scope():\n    enet = efn.EfficientNetB5(\n        input_shape=(img_size, img_size, 3),\n        weights='noisy-student',\n        include_top=False\n    )\n\n    model3 = tf.keras.Sequential([\n        enet,\n        tf.keras.layers.GlobalAveragePooling2D(),\n        tf.keras.layers.Dense(len(CLASSES), activation='softmax')\n    ]) \n\nmodel3.compile(\n    optimizer=tf.keras.optimizers.Adam(lr=0.0001),\n    loss = [categorical_focal_loss(gamma=2., alpha=.25)],\n    metrics=[tfa.metrics.F1Score(num_classes=104, average=\"macro\")]\n)\nmodel3.summary()\nmodel3.load_weights('../input/mytopmodel/weights_efficient_24(1).h5')","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"with strategy.scope():\n    enet = efn.EfficientNetB6(\n        input_shape=(img_size, img_size, 3),\n        weights='noisy-student',\n        include_top=False\n    )\n\n    model4 = tf.keras.Sequential([\n        enet,\n        tf.keras.layers.GlobalAveragePooling2D(),\n        tf.keras.layers.Dense(len(CLASSES), activation='softmax')\n    ]) \n\nmodel4.compile(\n    optimizer=tf.keras.optimizers.Adam(lr=0.0001),\n    loss = [categorical_focal_loss(gamma=2., alpha=.25)],\n    metrics=[tfa.metrics.F1Score(num_classes=104, average=\"macro\")]\n)\nmodel4.summary()\nmodel4.load_weights('../input/mytopmodel/weights_efficient_23.h5')","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"## Freeze the base classifiers and obtain meta-classifier","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"model11 = tf.keras.Sequential()\nfor layer in model1.layers[:-2]:\n    model11.add(layer)\nfor layer in model11.layers:\n    layer.trainable = False\nmodel22 = tf.keras.Sequential()\nfor layer in model2.layers[:-2]:\n    model22.add(layer)\nfor layer in model22.layers:\n    layer.trainable = False\nmodel33 = tf.keras.Sequential()\nfor layer in model3.layers[:-2]:\n    model33.add(layer)\nfor layer in model33.layers:\n    layer.trainable = False\nmodel44 = tf.keras.Sequential()\nfor layer in model4.layers[:-2]:\n    model44.add(layer)\nfor layer in model44.layers:\n    layer.trainable = False","execution_count":null,"outputs":[]},{"metadata":{"trusted":true},"cell_type":"code","source":"with strategy.scope():\n    \n    x = tf.keras.Input(shape = (img_size, img_size, 3))\n    x1 = model11(x)\n    x2 = model22(x)\n    x3 = model33(x)\n    x4 = model44(x)\n    x5 = tf.keras.layers.concatenate([x1, x2, x3, x4], axis = 3)\n    x6 = tf.keras.layers.GlobalAveragePooling2D()(x5)\n    x6 = tf.keras.layers.Dropout(0.75)(x6)\n    x6 = tf.keras.layers.Dense(len(CLASSES), activation='softmax')(x6)\n    out = tf.keras.Model(inputs = x, outputs = x6)\n\nout.compile(\n    optimizer=tf.keras.optimizers.Adam(lr=0.0001),\n    loss = [categorical_focal_loss(gamma=2., alpha=.25)],\n    metrics=[tfa.metrics.F1Score(num_classes=104, average=\"macro\")]\n)\nout.summary()","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"Skipping the training here ...","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"# history = out.fit(\n#     get_training_dataset(), \n#     steps_per_epoch=STEPS_PER_EPOCH,\n#     epochs=EPOCHS,\n#     callbacks=[lr_callback],\n#     validation_data=None if SKIP_VALIDATION else get_validation_dataset(),\n#     shuffle = True\n# )","execution_count":null,"outputs":[]},{"metadata":{},"cell_type":"markdown","source":"Load the model and predict, generate submission file","execution_count":null},{"metadata":{"trusted":true},"cell_type":"code","source":"out.load_weights('../input/mytopmodel/weights_ensemble_12.h5')\ntest_ds = get_test_dataset(ordered=True) # since we are splitting the dataset and iterating separately on images and ids, order matters.\ntest_images_ds = test_ds.map(lambda image, idnum: image)\nprint('Computing predictions...')\n# get the mean probability of the folds models\nprobabilities = out.predict(test_images_ds)\npredictions = np.argmax(probabilities, axis=-1)\nprint('Generating submission.csv file...')\ntest_ids_ds = test_ds.map(lambda image, idnum: idnum).unbatch()\ntest_ids = next(iter(test_ids_ds.batch(NUM_TEST_IMAGES))).numpy().astype('U') # all in one batch\nnp.savetxt('submission.csv', np.rec.fromarrays([test_ids, predictions]), fmt=['%s', '%d'], delimiter=',', header='id,label', comments='')","execution_count":null,"outputs":[]}],"metadata":{"kernelspec":{"language":"python","display_name":"Python 3","name":"python3"},"language_info":{"pygments_lexer":"ipython3","nbconvert_exporter":"python","version":"3.6.4","file_extension":".py","codemirror_mode":{"name":"ipython","version":3},"name":"python","mimetype":"text/x-python"}},"nbformat":4,"nbformat_minor":4}