public interface gebal
GEBAL balances a general complex matrix A. This involves, first,
permuting A by a similarity transformation to isolate eigenvalues
in the first 1 to ILO-1 and last IHI+1 to N elements on the
diagonal; and second, applying a diagonal similarity transformation
to rows and columns ILO to IHI to make the rows and columns as
close in norm as possible. Both steps are optional.
Balancing may reduce the 1-norm of the matrix, and improve the
accuracy of the computed eigenvalues and/or eigenvectors.
Subroutines
Arguments
| Type |
Intent | Optional | Attributes |
|
Name |
|
|
character(len=1),
|
intent(in) |
|
|
:: |
job |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
n |
|
|
complex(kind=sp),
|
intent(inout) |
|
|
:: |
a(lda,*) |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
lda |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
ilo |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
ihi |
|
|
real(kind=sp),
|
intent(out) |
|
|
:: |
scale(*) |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
info |
|
Arguments
| Type |
Intent | Optional | Attributes |
|
Name |
|
|
character(len=1),
|
intent(in) |
|
|
:: |
job |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
n |
|
|
real(kind=dp),
|
intent(inout) |
|
|
:: |
a(lda,*) |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
lda |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
ilo |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
ihi |
|
|
real(kind=dp),
|
intent(out) |
|
|
:: |
scale(*) |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
info |
|
Arguments
| Type |
Intent | Optional | Attributes |
|
Name |
|
|
character(len=1),
|
intent(in) |
|
|
:: |
job |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
n |
|
|
real(kind=sp),
|
intent(inout) |
|
|
:: |
a(lda,*) |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
lda |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
ilo |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
ihi |
|
|
real(kind=sp),
|
intent(out) |
|
|
:: |
scale(*) |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
info |
|
Arguments
| Type |
Intent | Optional | Attributes |
|
Name |
|
|
character(len=1),
|
intent(in) |
|
|
:: |
job |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
n |
|
|
complex(kind=dp),
|
intent(inout) |
|
|
:: |
a(lda,*) |
|
|
integer(kind=ilp),
|
intent(in) |
|
|
:: |
lda |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
ilo |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
ihi |
|
|
real(kind=dp),
|
intent(out) |
|
|
:: |
scale(*) |
|
|
integer(kind=ilp),
|
intent(out) |
|
|
:: |
info |
|
Module Procedures