numpy_helper.py 文件源码

def normalize_mean_std(X, x_mean=None, x_std=None, axis=0, ignore_nan=False):
    if ignore_nan:
        mean = np.nanmean
        std = np.nanstd
    else:
        mean = np.mean
        std = np.std

    if x_mean is None:
        x_mean = mean(X, axis=axis, keepdims=True)
    if x_std is None:
        x_std = std(X, axis=axis, keepdims=True)
        x_std[~np.isfinite(1 / x_std)] = 1

    if np.any(~np.isfinite(x_mean)):
        warnings.warn("x_mean contains NaN or Inf values!")
    if np.any(~np.isfinite(x_std)):
        warnings.warn("x_std contains NaN or Inf values!")

    X = X - x_mean
    X = X / x_std

    return X, x_mean, x_std