Esempio n. 1
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def main():
    """Train neural network implementation on the MNIST dataset.
    """
    # load the MNIST dataset and apply min/max scaling to scale the pixel intensity values
    # to the range [0, 1] (each image is represented by an 8 x 8 = 64-dim feature vector)
    print("[INFO] loading MNIST (sample) dataset...")
    digits = datasets.load_digits()
    data = digits.data.astype("float")  # pylint: disable=no-member
    data = (data - data.min()) / (data.max() - data.min())
    print("[INFO] samples: {}, dim: {}".format(data.shape[0], data.shape[1]))

    # construct the training and testing splits
    (train_x, test_x, train_y, test_y) = \
        train_test_split(data, digits.target, test_size=0.25)  # pylint: disable=no-member

    # convert the labels from integers to vectors using one-hot-encoding
    train_y = LabelBinarizer().fit_transform(train_y)
    test_y = LabelBinarizer().fit_transform(test_y)

    # train the network
    print("[INFO] training network...")
    network = NeuralNetwork([train_x.shape[1], 32, 16, 10])
    print("[INFO] {}".format(network))
    network.fit(train_x, train_y, epochs=1000)

    # evaluate the network
    print("[INFO] evaluating network...")
    predictions = network.predict(test_x)
    predictions = predictions.argmax(axis=1)
    print(classification_report(test_y.argmax(axis=1), predictions))
Esempio n. 2
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def main():
    """Run neural network on XOR dataset.
    """
    # construct the XOR dataset
    X = np.array([[0, 0], [0, 1], [1, 0], [1, 1]])
    y = np.array([[0], [1], [1], [0]])

    # define our 2-2-1 neural network and train it
    network = NeuralNetwork([2, 2, 1], alpha=0.5)
    network.fit(X, y, epochs=20000)

    # now that our network is trained, loop over the XOR data points
    for (value, target) in zip(X, y):
        # make a prediction on the data point and display the result
        # to our console
        pred = network.predict(value)[0][0]
        step = 1 if pred > 0.5 else 0
        print("[INFO] data={}, ground-truth={}, pred={:.4f}, step={}".format(
            value, target[0], pred, step))
Esempio n. 3
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from pyimagesearch.nn import NeuralNetwork
from sklearn import datasets

# load the MNIST dataset and apply min/max scaling to scale the
# pixel intensity values to the range [0, 1] (each image is
# represented by an 8 x 8 = 64-dim feature vector)
print('[INFO] loading MNIST(sample) dataset')
digits = datasets.load_digits()
data = digits.data.astype('float')
data = (data - data.min()) / (data.max() - data.min())
print(f'[INFO] samples: {data.shape[0]}, dim: {data.shape[1]}')

trainX, testX, trainY, testY = train_test_split(data,
                                                digits.target,
                                                test_size=0.25)

# convert the labels from integers to vectors
trainY = LabelBinarizer().fit_transform(trainY)
testY = LabelBinarizer().fit_transform(testY)

# train the neural network
print('[INFO] training neurall network...')
nn = NeuralNetwork([trainX.shape[1], 32, 16, 10])
print(f'[INFO] {nn}')
nn.fit(trainX, trainY, epochs=1000)

# Evaluate network
print('[INFO] evaluating network...')
predictions = nn.predict(testX)
predictions = predictions.argmax(axis=1)
print(classification_report(testY.argmax(axis=1), predictions))
Esempio n. 4
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# import the neccessary packages
from pyimagesearch.nn import NeuralNetwork 
import numpy as np

# contruct the XOR dataset
X = np.array([[0, 0], [0, 1], [1, 0], [1, 1]])
y = np.array([[0], [1], [1], [0]])

# define our 2-2-1 neural network and train it
nn = NeuralNetwork([2, 2, 1], alpha=0.5)
nn.fit(X, y, epochs=20000)

# now that our network is trained, loop over the XOR data points
for (x, target) in zip(X, y):
    # make a prediction on the data point and display the result
    # to our console
    pred = nn.predict(x)[0][0]
    step = 1 if pred > 0.5 else 0
    print("[INFO] data={}, ground-truth={}, pred={:.4f}, step={}".format(
        x, target[0], pred, step))
Esempio n. 5
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from pyimagesearch.nn import NeuralNetwork
import numpy as np
import argparse

ap = argparse.ArgumentParser()
ap.add_argument("-e",
                "--epochs",
                default="20000",
                help="number of epochs to train the neural network")
args = vars(ap.parse_args())

X = np.array([[0, 0], [0, 1], [1, 0], [1, 1]])
y = np.array([[0], [1], [1], [0]])

nn = NeuralNetwork([2, 2, 1], alpha=0.5)
nn.fit(X, y, epochs=int(args["epochs"]))

for (x, target) in zip(X, y):
    pred = nn.predict(x)[0][
        0]  # [0][0] to get the predict value from the array
    step = 1 if pred > 0.5 else 0
    print("[INFO] data={}, ground-truth={}, pred={:.4f}, step={}".format(
        x, target, pred, step))