Buckling Mode

 

Driver dsdrv5  implements the Buckling transformation. Eigenvalues closest to a shift can be obtained by computing the selected eigenvalues of

Settings of which are the same as those of the shift-invert modes. This mode assumes that ${\bf A}$ is a symmetric postive semi definite matrix. Note that the operator OP is symmetric with respect to the semi-inner product defined by The eigenvalue of the original problem and are related by

Note that should not be used for this mode. The two operations

are required in order to use this driver.