Store the matrix correctly

The band routines assume the matrix ${\bf A}$ and ${\bf M}$ are stored in LAPACK band form. In the following we used AB and MB to denote ${\bf A}$ and B stored in band form. If the matrix ${\bf A}$ has kl subdiagonals and ku superdiagonals, then the ijth element of A a_ij is stored in AB(kl+ku+1+i-j,j) for . An example of a band matrix ${\bf A}$ with kl=2, ku=1 is illustrated below.

The elements marked * in the matrix AB need not be set.