30eadc321c1755eca615a39bb4b8b5fc1e769f70,dipy/reconst/mdki.py,,_wls_fit_mdki,#,288

Before Change

           Meeting of the ISMRM; Honolulu. April 22-28
    
    // Define weights as diag(sqrt(ng) * msignal ** 2)
    W = np.diag(ng * msignal ** 2)

    // WLS solution
    BTW = np.dot(design_matrix.T, W)
    inv_BT_W_B = np.linalg.pinv(np.dot(BTW, design_matrix))
    invBTWB_BTW = np.dot(inv_BT_W_B, BTW)
    params = np.dot(invBTWB_BTW, np.log(msignal))

After Change

    w = ng * msignal ** 2

    // BTW = (Bw).T, where w are diag of W
    BTW = (w[..., None] * design_matrix).T
    inv_BT_W_B = np.linalg.pinv(np.einsum("...ij,jk->...ik", BTW,
                                          design_matrix))  // dot product
    invBTWB_BTW = np.einsum("...ij,...jk->...ik", inv_BT_W_B, BTW)

Instances