treetime/treeregression.py
def base_regression(Q, slope=None):
    """
    this function calculates the regression coefficients for a
    given vector containing the averages of tip and branch
    quantities.

    Parameters
    ----------
    Q : numpy.array
        vector with
    slope : None, optional
        Description

    Returns
    -------
    TYPE
        Description
    """
    if slope is None:
        slope = (Q[dtavgii] - Q[tavgii]*Q[davgii]/Q[sii]) \
                /(Q[tsqii] - Q[tavgii]**2/Q[sii])
        only_intercept=False
    else:
        only_intercept=True

    intercept = (Q[davgii] - Q[tavgii]*slope)/Q[sii]

    if only_intercept:
        return {'slope':slope, 'intercept':intercept,
                'chisq': 0.5*(Q[dsqii]/Q[sii] - Q[davgii]**2/Q[sii]**2)}

    chisq = 0.5*(Q[dsqii] - Q[davgii]**2/Q[sii]
                - (Q[dtavgii] - Q[davgii]*Q[tavgii]/Q[sii])**2/(Q[tsqii]
                - Q[tavgii]**2/Q[sii]))

    estimator_hessian = np.array([[Q[tsqii], Q[tavgii]], [Q[tavgii], Q[sii]]])

    return {'slope':slope, 'intercept':intercept,
            'chisq':chisq, 'hessian':estimator_hessian,
            'cov':np.linalg.inv(estimator_hessian)}
def base_regression(Q, slope=None):
    """
    this function calculates the regression coefficients for a
    given vector containing the averages of tip and branch
    quantities.

    Parameters
    ----------
    Q : numpy.array
        vector with
    slope : None, optional
        Description

    Returns
    -------
    TYPE
        Description
    """
    if slope is None:
        slope = (Q[dtavgii] - Q[tavgii]*Q[davgii]/Q[sii]) \
                /(Q[tsqii] - Q[tavgii]**2/Q[sii])
        only_intercept=False
    else:
        only_intercept=True

    intercept = (Q[davgii] - Q[tavgii]*slope)/Q[sii]

    if only_intercept:
        return {'slope':slope, 'intercept':intercept,
                'chisq': 0.5*(Q[dsqii]/Q[sii] - Q[davgii]**2/Q[sii]**2)}

    chisq = 0.5*(Q[dsqii] - Q[davgii]**2/Q[sii]
                - (Q[dtavgii] - Q[davgii]*Q[tavgii]/Q[sii])**2/(Q[tsqii]
                - Q[tavgii]**2/Q[sii]))

    estimator_hessian = np.array([[Q[tsqii], Q[tavgii]], [Q[tavgii], Q[sii]]])

    return {'slope':slope, 'intercept':intercept,
            'chisq':chisq, 'hessian':estimator_hessian,
            'cov':np.linalg.inv(estimator_hessian)}
this function calculates the regression coefficients for a
    given vector containing the averages of tip and branch
    quantities.

    Parameters
    ----------
    Q : numpy.array
        vector with
    slope : None, optional
        Description

    Returns
    -------
    TYPE
        Description