def manual_bn()

in models/layers/normalization.py [0:0]


def manual_bn(x, gain=None, bias=None, return_mean_var=False, eps=1e-5):
    # Cast x to float32 if necessary
    float_x = x.float()
    # Calculate expected value of x (m) and expected value of x**2 (m2)
    # Mean of x
    m = torch.mean(float_x, [0, 2, 3], keepdim=True)
    # Mean of x squared
    m2 = torch.mean(float_x ** 2, [0, 2, 3], keepdim=True)
    # Calculate variance as mean of squared minus mean squared.
    var = m2 - m ** 2
    # Cast back to float 16 if necessary
    var = var.type(x.type())
    m = m.type(x.type())
    # Return mean and variance for updating stored mean/var if requested
    if return_mean_var:
        return fused_bn(x, m, var, gain, bias, eps), m.squeeze(), var.squeeze()
    else:
        return fused_bn(x, m, var, gain, bias, eps)