def clean(features):
    """
    Sanitize the dataset for analysis by centering the means to 0 and creating unit variance
    """
    means = features.mean(axis=0)
    sd = features.std(axis=0)
    cleaned = features
    for j in range(features.shape[1]):
        cleaned.T[j] = [(i-means[j])/sd[j] for i in cleaned.T[j]]
    return (cleaned,means,sd)