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solutions/9 Improving performance Exercises Solutions.ipynb
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520
solutions/9 Improving performance Exercises Solutions.ipynb
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{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"# 9 Improving performance Exercises Solutions"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"import pandas as pd\n",
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"import numpy as np\n",
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"%matplotlib inline\n",
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"import matplotlib.pyplot as plt"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Exercise 1\n",
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"\n",
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"- Reload the IMDB data keeping only the first 20000 most common words\n",
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"- pad the reviews to a shorter length (eg. 70 or 80), this time make sure you keep the first part of the review if it's longer than the maximum length\n",
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"- re run the model (remember to set max_features correctly)\n",
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"- does it train faster this time?\n",
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"- do you get a better performance?"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"from tensorflow.keras.datasets import imdb\n",
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"from tensorflow.keras.preprocessing.sequence import pad_sequences\n",
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"from tensorflow.keras.models import Sequential\n",
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"from tensorflow.keras.layers import Embedding, LSTM, Dense"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"max_features = 20000\n",
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"skip_top = 200"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"(X_train, y_train), (X_test, y_test) = imdb.load_data('/tmp/imdb.npz',\n",
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" num_words=max_features,\n",
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" start_char=1,\n",
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" oov_char=2,\n",
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" index_from=3)"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"X_train.shape"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"maxlen = 80"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"X_train_pad = pad_sequences(X_train, maxlen=maxlen, truncating='post')\n",
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"X_test_pad = pad_sequences(X_test, maxlen=maxlen, truncating='post')"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"model = Sequential()\n",
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"model.add(Embedding(max_features, 128))\n",
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"model.add(LSTM(64, dropout=0.2, recurrent_dropout=0.2))\n",
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"model.add(Dense(1, activation='sigmoid'))\n",
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"\n",
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"model.compile(loss='binary_crossentropy',\n",
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" optimizer='adam',\n",
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" metrics=['accuracy'])"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"X_train[0]"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"model.fit(X_train_pad, y_train,\n",
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" batch_size=32,\n",
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" epochs=2,\n",
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" validation_split=0.3)"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"score, acc = model.evaluate(X_test_pad, y_test)\n",
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"print('Test score:', score)\n",
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"print('Test accuracy:', acc)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Exercise 2\n",
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"\n",
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"- Reload the digits data as above\n",
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"- define a function repeated_training_reg_dropout that adds regularization and dropout to a fully connected network\n",
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"- compare the performance with/witouth dropout and regularization like we did for batch normalization\n",
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"- do you get a better performance?"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"from sklearn.datasets import load_digits\n",
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"from tensorflow.keras.utils import to_categorical\n",
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"from sklearn.model_selection import train_test_split\n",
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"from tensorflow.keras.layers import Dropout\n",
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"import tensorflow.keras.backend as K"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"digits = load_digits()\n",
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"X, y = digits.data, digits.target\n",
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"y_cat = to_categorical(y)\n",
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"\n",
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"X_train, X_test, y_train, y_test = train_test_split(X, y_cat, test_size=0.3)"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"def repeated_training_reg_dropout(X_train,\n",
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" y_train,\n",
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" X_test,\n",
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" y_test,\n",
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" units=512,\n",
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" activation='sigmoid',\n",
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" optimizer='sgd',\n",
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" do_dropout=False,\n",
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" rate=0.3,\n",
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" kernel_regularizer='l2',\n",
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" epochs=10,\n",
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" repeats=3):\n",
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" histories = []\n",
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" \n",
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" for repeat in range(repeats):\n",
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" K.clear_session()\n",
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"\n",
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" model = Sequential()\n",
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" \n",
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" # first fully connected layer\n",
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" model.add(Dense(units,\n",
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" input_shape=X_train.shape[1:],\n",
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" kernel_initializer='normal',\n",
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" kernel_regularizer=kernel_regularizer,\n",
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" activation=activation))\n",
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" if do_dropout:\n",
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" model.add(Dropout(rate))\n",
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"\n",
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" # second fully connected layer\n",
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" model.add(Dense(units,\n",
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" kernel_initializer='normal',\n",
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" kernel_regularizer=kernel_regularizer,\n",
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" activation=activation))\n",
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" if do_dropout:\n",
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" model.add(Dropout(rate))\n",
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"\n",
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" # third fully connected layer\n",
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" model.add(Dense(units,\n",
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" kernel_initializer='normal',\n",
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" kernel_regularizer=kernel_regularizer,\n",
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" activation=activation))\n",
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" if do_dropout:\n",
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" model.add(Dropout(rate))\n",
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"\n",
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" # output layer\n",
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" model.add(Dense(10, activation='softmax'))\n",
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" \n",
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" model.compile(optimizer,\n",
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" 'categorical_crossentropy',\n",
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" metrics=['accuracy'])\n",
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"\n",
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" h = model.fit(X_train, y_train, validation_data=(X_test, y_test), epochs=epochs, verbose=0)\n",
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" histories.append([h.history['accuracy'], h.history['val_accuracy']])\n",
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" print(repeat, end=' ')\n",
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"\n",
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" histories = np.array(histories)\n",
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" \n",
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" # calculate mean and standard deviation across repeats:\n",
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" mean_acc = histories.mean(axis=0)\n",
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" std_acc = histories.std(axis=0)\n",
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" print()\n",
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" \n",
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" return mean_acc[0], std_acc[0], mean_acc[1], std_acc[1]"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"mean_acc, std_acc, mean_acc_val, std_acc_val = repeated_training_reg_dropout(X_train,\n",
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" y_train,\n",
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" X_test,\n",
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" y_test,\n",
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" do_dropout=False)"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"mean_acc_do, std_acc_do, mean_acc_val_do, std_acc_val_do = repeated_training_reg_dropout(X_train,\n",
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" y_train,\n",
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" X_test,\n",
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" y_test,\n",
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" do_dropout=True)"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"def plot_mean_std(m, s):\n",
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" plt.plot(m)\n",
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" plt.fill_between(range(len(m)), m-s, m+s, alpha=0.1)"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"plot_mean_std(mean_acc, std_acc)\n",
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"plot_mean_std(mean_acc_val, std_acc_val)\n",
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"plot_mean_std(mean_acc_do, std_acc_do)\n",
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"plot_mean_std(mean_acc_val_do, std_acc_val_do)\n",
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"plt.ylim(0, 1.01)\n",
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"plt.title(\"Dropout and Regularization Accuracy\")\n",
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"plt.xlabel('Epochs')\n",
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"plt.ylabel('Accuracy')\n",
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"plt.legend(['Train', 'Test', 'Train with Dropout and Regularization', 'Test with Dropout and Regularization'], loc='best')"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Exercise 3\n",
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"\n",
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"This is a very long and complex exercise, that should give you an idea of a real world scenario. Feel free to look at the solution if you feel lost. Also, feel free to run this with a GPU, in which case you don't need to download the data.\n",
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"\n",
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"If you are running this locally, download and unpack the male/female pictures from [here](https://www.dropbox.com/s/nov493om2jmh2gp/male_female.tgz?dl=0). These images and labels were obtained from [Crowdflower](https://www.crowdflower.com/data-for-everyone/).\n",
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"\n",
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"Your goal is to build an image classifier that will recognize the gender of a person from pictures.\n",
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"\n",
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"- Have a look at the directory structure and inspect a couple of pictures\n",
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"- Design a model that will take a color image of size 64x64 as input and return a binary output (female=0/male=1)\n",
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"- Feel free to introduce any regularization technique in your model (Dropout, Batch Normalization, Weight Regularization)\n",
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"- Compile your model with an optimizer of your choice\n",
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"- Using `ImageDataGenerator`, define a train generator that will augment your images with some geometric transformations. Feel free to choose the parameters that make sense to you.\n",
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"- Define also a test generator, whose only purpose is to rescale the pixels by 1./255\n",
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"- use the function `flow_from_directory` to generate batches from the train and test folders. Make sure you set the `target_size` to 64x64.\n",
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"- Use the `model.fit_generator` function to fit the model on the batches generated from the ImageDataGenerator. Since you are streaming and augmenting the data in real time you will have to decide how many batches make an epoch and how many epochs you want to run\n",
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"- Train your model (you should get to at least 85% accuracy)\n",
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"- Once you are satisfied with your training, check a few of the misclassified pictures. Are those sensible errors?"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"# If you are running this locally\n",
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"# uncomment the next 4 lines to download, extract and set the data path:\n",
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"# !wget 'https://www.dropbox.com/s/nov493om2jmh2gp/male_female.tgz?dl=1' -O ../data/male_female.tgz\n",
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"# data_path = '../data/male_female'\n",
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"# !mkdir -p {data_path}\n",
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"# !tar -xzvf ../data/male_female.tgz --directory {data_path}"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
|
||||
"from tensorflow.keras.layers import Conv2D\n",
|
||||
"from tensorflow.keras.layers import MaxPooling2D\n",
|
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"from tensorflow.keras.layers import Flatten\n",
|
||||
"from tensorflow.keras.layers import BatchNormalization\n",
|
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"from itertools import islice\n",
|
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"from tensorflow.keras.preprocessing.image import ImageDataGenerator"
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]
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||||
},
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||||
{
|
||||
"cell_type": "code",
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||||
"execution_count": null,
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||||
"metadata": {},
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||||
"outputs": [],
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||||
"source": [
|
||||
"K.clear_session()\n",
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"\n",
|
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"model = Sequential()\n",
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"model.add(Conv2D(32, (3, 3), input_shape = (64, 64, 3), activation = 'relu'))\n",
|
||||
"model.add(MaxPooling2D(pool_size = (2, 2)))\n",
|
||||
"model.add(BatchNormalization())\n",
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||||
"\n",
|
||||
"model.add(Conv2D(64, (3, 3), activation = 'relu'))\n",
|
||||
"model.add(MaxPooling2D(pool_size = (2, 2)))\n",
|
||||
"model.add(BatchNormalization())\n",
|
||||
"\n",
|
||||
"model.add(Conv2D(64, (3, 3), activation = 'relu'))\n",
|
||||
"model.add(MaxPooling2D(pool_size = (2, 2)))\n",
|
||||
"model.add(BatchNormalization())\n",
|
||||
"\n",
|
||||
"model.add(Flatten())\n",
|
||||
"\n",
|
||||
"model.add(Dense(128, activation = 'relu'))\n",
|
||||
"model.add(Dense(1, activation = 'sigmoid'))"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": null,
|
||||
"metadata": {},
|
||||
"outputs": [],
|
||||
"source": [
|
||||
"model.compile(optimizer = 'adam',\n",
|
||||
" loss = 'binary_crossentropy',\n",
|
||||
" metrics = ['accuracy'])\n",
|
||||
"\n",
|
||||
"model.summary()"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": null,
|
||||
"metadata": {},
|
||||
"outputs": [],
|
||||
"source": [
|
||||
"train_gen = ImageDataGenerator(rescale = 1./255,\n",
|
||||
" width_shift_range=0.1,\n",
|
||||
" height_shift_range=0.1,\n",
|
||||
" rotation_range = 10,\n",
|
||||
" shear_range = 0.2,\n",
|
||||
" zoom_range = 0.2,\n",
|
||||
" horizontal_flip = True)\n",
|
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"\n",
|
||||
"test_gen = ImageDataGenerator(rescale = 1./255)"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": null,
|
||||
"metadata": {},
|
||||
"outputs": [],
|
||||
"source": [
|
||||
"train = train_gen.flow_from_directory(data_path + '/train',\n",
|
||||
" target_size = (64, 64),\n",
|
||||
" batch_size = 16,\n",
|
||||
" class_mode = 'binary')\n",
|
||||
"\n",
|
||||
"test = test_gen.flow_from_directory(data_path + '/test',\n",
|
||||
" target_size = (64, 64),\n",
|
||||
" batch_size = 16,\n",
|
||||
" class_mode = 'binary')"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": null,
|
||||
"metadata": {},
|
||||
"outputs": [],
|
||||
"source": [
|
||||
"model.fit(train,\n",
|
||||
" steps_per_epoch = 800,\n",
|
||||
" epochs = 200,\n",
|
||||
" validation_data = test,\n",
|
||||
" validation_steps = 200)"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": null,
|
||||
"metadata": {},
|
||||
"outputs": [],
|
||||
"source": [
|
||||
"X_test = []\n",
|
||||
"y_test = []\n",
|
||||
"for ts in islice(test, 50):\n",
|
||||
" X_test.append(ts[0])\n",
|
||||
" y_test.append(ts[1])\n",
|
||||
"\n",
|
||||
"X_test = np.concatenate(X_test)\n",
|
||||
"y_test = np.concatenate(y_test)"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": null,
|
||||
"metadata": {},
|
||||
"outputs": [],
|
||||
"source": [
|
||||
"y_pred = model.predict_classes(X_test).ravel()"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": null,
|
||||
"metadata": {},
|
||||
"outputs": [],
|
||||
"source": [
|
||||
"np.argwhere(y_test != y_pred).ravel()"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": null,
|
||||
"metadata": {},
|
||||
"outputs": [],
|
||||
"source": [
|
||||
"plt.imshow(X_test[14])"
|
||||
]
|
||||
},
|
||||
{
|
||||
"cell_type": "code",
|
||||
"execution_count": null,
|
||||
"metadata": {},
|
||||
"outputs": [],
|
||||
"source": []
|
||||
}
|
||||
],
|
||||
"metadata": {
|
||||
"kernelspec": {
|
||||
"display_name": "Python 3",
|
||||
"language": "python",
|
||||
"name": "python3"
|
||||
},
|
||||
"language_info": {
|
||||
"codemirror_mode": {
|
||||
"name": "ipython",
|
||||
"version": 3
|
||||
},
|
||||
"file_extension": ".py",
|
||||
"mimetype": "text/x-python",
|
||||
"name": "python",
|
||||
"nbconvert_exporter": "python",
|
||||
"pygments_lexer": "ipython3",
|
||||
"version": "3.7.10"
|
||||
}
|
||||
},
|
||||
"nbformat": 4,
|
||||
"nbformat_minor": 2
|
||||
}
|
||||
Reference in New Issue
Block a user