To have a more complete description of the problem, access here .

Here a computer program is provided. To directly run this program, acess here.

Suppose that symmetric matrices , , are given such that the undamped model , where , has eigenstructure sets and (in compact representation) such that

- the first, satisfying , where is a diagonal matrix with non-positive entries (eigenvalue matrix), is the corresponding eigenvector matrix, represent part of the eigenstructure which we want to update, to which the vibration test gives measured data matrices and (only first entries of corresponding mode shapes are measured);
- the last, satisfying , where , , the eigenvector matrix, represent an unknown part of the eigenstructure which we want to not get changed.

Here, we provide a computer program to compute this matrix , following
an algorithm given in J. Carvalho, *State Estimation and Finite-Element
Model Updating in Vibrating Systems*, PhD. Dissert, NIU, 2002.

Although the algorithm itself does not require direct information on to compute , the eigenvalue matrix must still be provided in order to compute the quantity

Here a computer program is provided. To run this program, acess here.

Joao Carvalho 2006-03-17