def stable_cho_factor(x,tiny=_TINY):
    """
    NAME:
       stable_cho_factor
    PURPOSE:
       Stable version of the cholesky decomposition
    INPUT:
       x - (sc.array) positive definite matrix
       tiny - (double) tiny number to add to the covariance matrix to make the decomposition stable (has a default)
    OUTPUT:
       (L,lowerFlag) - output from scipy.linalg.cho_factor for lower=True
    REVISION HISTORY:
       2009-09-25 - Written - Bovy (NYU)
    """
    return linalg.cho_factor(x+numpy.sum(numpy.diag(x))*tiny*numpy.eye(x.shape[0]),lower=True)
NAME:
       stable_cho_factor
    PURPOSE:
       Stable version of the cholesky decomposition
    INPUT:
       x - (sc.array) positive definite matrix
       tiny - (double) tiny number to add to the covariance matrix to make the decomposition stable (has a default)
    OUTPUT:
       (L,lowerFlag) - output from scipy.linalg.cho_factor for lower=True
    REVISION HISTORY:
       2009-09-25 - Written - Bovy (NYU)