def __init__()

in imnet_evaluate/pnasnet.py [0:0]


    def __init__(self, in_channels_left, out_channels_left, in_channels_right,
                 out_channels_right, is_reduction=False, zero_pad=False,
                 match_prev_layer_dimensions=False):
        super(Cell, self).__init__()

        # If `is_reduction` is set to `True` stride 2 is used for
        # convolutional and pooling layers to reduce the spatial size of
        # the output of a cell approximately by a factor of 2.
        stride = 2 if is_reduction else 1

        # If `match_prev_layer_dimensions` is set to `True`
        # `FactorizedReduction` is used to reduce the spatial size
        # of the left input of a cell approximately by a factor of 2.
        self.match_prev_layer_dimensions = match_prev_layer_dimensions
        if match_prev_layer_dimensions:
            self.conv_prev_1x1 = FactorizedReduction(in_channels_left,
                                                     out_channels_left)
        else:
            self.conv_prev_1x1 = ReluConvBn(in_channels_left,
                                            out_channels_left, kernel_size=1)

        self.conv_1x1 = ReluConvBn(in_channels_right, out_channels_right,
                                   kernel_size=1)
        self.comb_iter_0_left = BranchSeparables(out_channels_left,
                                                 out_channels_left,
                                                 kernel_size=5, stride=stride,
                                                 zero_pad=zero_pad)
        self.comb_iter_0_right = MaxPool(3, stride=stride, zero_pad=zero_pad)
        self.comb_iter_1_left = BranchSeparables(out_channels_right,
                                                 out_channels_right,
                                                 kernel_size=7, stride=stride,
                                                 zero_pad=zero_pad)
        self.comb_iter_1_right = MaxPool(3, stride=stride, zero_pad=zero_pad)
        self.comb_iter_2_left = BranchSeparables(out_channels_right,
                                                 out_channels_right,
                                                 kernel_size=5, stride=stride,
                                                 zero_pad=zero_pad)
        self.comb_iter_2_right = BranchSeparables(out_channels_right,
                                                  out_channels_right,
                                                  kernel_size=3, stride=stride,
                                                  zero_pad=zero_pad)
        self.comb_iter_3_left = BranchSeparables(out_channels_right,
                                                 out_channels_right,
                                                 kernel_size=3)
        self.comb_iter_3_right = MaxPool(3, stride=stride, zero_pad=zero_pad)
        self.comb_iter_4_left = BranchSeparables(out_channels_left,
                                                 out_channels_left,
                                                 kernel_size=3, stride=stride,
                                                 zero_pad=zero_pad)
        if is_reduction:
            self.comb_iter_4_right = ReluConvBn(out_channels_right,
                                                out_channels_right,
                                                kernel_size=1, stride=stride)
        else:
            self.comb_iter_4_right = None