lsmrblas Module

This file contains the following BLAS routines dcopy, ddot, dnrm2, dscal required by subroutines lsmr and acheck.

References

• Jack Dongarra, Jim Bunch, Cleve Moler, Pete Stewart, LINPACK User's Guide, SIAM, 1979, ISBN13: 978-0-898711-72-1, LC: QA214.L56.
• Charles Lawson, Richard Hanson, David Kincaid, Fred Krogh, Algorithm 539, Basic Linear Algebra Subprograms for Fortran Usage, ACM Transactions on Mathematical Software, Volume 5, Number 3, September 1979, pages 308-323.

Functions

public function ddot(n, dx, incx, dy, incy)

Dot product of two vectors.

Arguments

Type	Intent	Optional	Attributes		Name
integer(kind=ip),	intent(in)			::	n	the number of entries in the vectors.
real(kind=wp),	intent(in)			::	dx(*)	the first vector
integer(kind=ip),	intent(in)			::	incx	the increment between successive entries in DX.
real(kind=wp),	intent(in)			::	dy(*)	the second vector
integer(kind=ip),	intent(in)			::	incy	the increment between successive entries in DY.

Return Value real(kind=wp)

public function dnrm2(n, x, incx)

The euclidean norm of a vector sqrt ( X' * X ).

Arguments

Type	Intent	Optional	Attributes		Name
integer(kind=ip),	intent(in)			::	n
real(kind=wp),	intent(in)			::	x(*)
integer(kind=ip),	intent(in)			::	incx

Return Value real(kind=wp)

Subroutines

public subroutine dcopy(n, dx, incx, dy, incy)

Copies a vector X to a vector Y.

Arguments

Type	Intent	Optional	Attributes		Name
integer(kind=ip)				::	n
real(kind=wp)				::	dx(*)
integer(kind=ip)				::	incx
real(kind=wp)				::	dy(*)
integer(kind=ip)				::	incy

public subroutine dscal(n, sa, x, incx)

Scales a vector by a constant.

Arguments

Type	Intent	Optional	Attributes		Name
integer(kind=ip),	intent(in)			::	n	the number of entries in the vector.
real(kind=wp),	intent(in)			::	sa	the multiplier.
real(kind=wp),	intent(inout)			::	x(*)	the vector to be scaled.
integer(kind=ip),	intent(in)			::	incx	the increment between successive entries of X.