Class: Daimond::Data::MNIST

Inherits:
Object
  • Object
show all
Defined in:
lib/daimond/data/mnist.rb

Constant Summary collapse

URL_BASE = 
'https://ossci-datasets.s3.amazonaws.com/mnist/'
FILES = 
{
  train_images: 'train-images-idx3-ubyte.gz',
  train_labels: 'train-labels-idx1-ubyte.gz',
  test_images: 't10k-images-idx3-ubyte.gz',
  test_labels: 't10k-labels-idx1-ubyte.gz'
}

Class Method Summary collapse

Class Method Details

.download(file, path: 'data/mnist') ⇒ Object 



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# File 'lib/daimond/data/mnist.rb', line 16

def self.download(file, path: 'data/mnist')
  ::FileUtils.mkdir_p(path)  # <-- Здесь изменение: создаёт и data, и data/mnist
  filepath = File.join(path, file)

  unless File.exist?(filepath)
    puts "Downloading #{file}..."
    URI.open("#{URL_BASE}#{file}") do |f|
      File.open(filepath, 'wb') { |out| out.write(f.read) }
    end
  end
  filepath
end

.load_images(file) ⇒ Object 



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# File 'lib/daimond/data/mnist.rb', line 29

def self.load_images(file)
  filepath = download(file)
  Zlib::GzipReader.open(filepath) do |f|
    magic = f.read(4).unpack('N').first
    n_images = f.read(4).unpack('N').first
    n_rows = f.read(4).unpack('N').first
    n_cols = f.read(4).unpack('N').first

    images = f.read(n_images * n_rows * n_cols).unpack('C*')
    # Нормализация в [0, 1] и reshape в [n_images, 784]
    images.each_slice(n_rows * n_cols).map do |img|
      img.map { |pixel| pixel / 255.0 }
    end
  end
end

.load_labels(file) ⇒ Object 



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# File 'lib/daimond/data/mnist.rb', line 45

def self.load_labels(file)
  filepath = download(file)
  Zlib::GzipReader.open(filepath) do |f|
    magic = f.read(4).unpack('N').first
    n_labels = f.read(4).unpack('N').first
    labels = f.read(n_labels).unpack('C*')
    labels
  end
end