`scipy.linalg._fblas:dgbmv`

Signature

def dgbmv(m, n, kl, ku, alpha, a, x, incx = 1, offx = 0, beta = 0.0, y = None, incy = 1, offy = 0, trans = 0, overwrite_y = 0)

Compute y = alpha*op(a)@x + beta*y for a banded matrix a (BLAS dgbmv).

m : int: Number of rows of the full matrix.
n : int: Number of columns of the full matrix.
kl : int: Number of sub-diagonals.
ku : int: Number of super-diagonals.
alpha : float: Scalar multiplier for the product.
a : ndarray: Banded storage of the matrix, shape (kl + ku + 1, n).
x : ndarray: Input vector.
incx : int, optional: Stride between successive elements of x. Default is 1.
offx : int, optional: Index of the first element of x to use. Default is 0.
beta : float, optional: Scalar multiplier for y. Default is 0.
y : ndarray, optional: Input/output vector; if omitted a new zero vector is allocated. Default is None.
incy : int, optional: Stride between successive elements of y. Default is 1.
offy : int, optional: Index of the first element of y to use. Default is 0.
trans : int, optional: Operation on the matrix: 0 none, 1 transpose, 2 conjugate transpose. Default is 0.
overwrite_y : int, optional: If nonzero, y may be overwritten in place. Default is 0.