Developer Reference

  • 2020.2
  • 07/15/2020
  • Public Content
Contents

?trmvt

Performs matrix-vector operations.

Syntax

call strmvt
(
uplo
,
n
,
t
,
ldt
,
x
,
incx
,
y
,
incy
,
w
,
incw
,
z
,
incz
)
call dtrmvt
(
uplo
,
n
,
t
,
ldt
,
x
,
incx
,
y
,
incy
,
w
,
incw
,
z
,
incz
)
call ctrmvt
(
uplo
,
n
,
t
,
ldt
,
x
,
incx
,
y
,
incy
,
w
,
incw
,
z
,
incz
)
call ztrmvt
(
uplo
,
n
,
t
,
ldt
,
x
,
incx
,
y
,
incy
,
w
,
incw
,
z
,
incz
)
Description
?trmvt
performs the matrix-vector operations as follows:
strmvt
and
dtrmvt
:   x :=
T
' *y, and w :=
T
*z
ctrmvt
and
ztrmvt
:   x := conjg(
T
' ) *y, and w :=
T
*z,
where x is an
n
element vector and
T
is an
n
-by-
n
upper or lower triangular matrix.
Input Parameters
uplo
CHARACTER*1.
On entry,
uplo
specifies whether the matrix is an upper or lower triangular matrix as follows:
uplo
= 'U' or 'u'
A
is an upper triangular matrix.
uplo
= 'L' or 'l'
A
is a lower triangular matrix.
Unchanged on exit.
n
INTEGER.
On entry,
n
specifies the order of the matrix
A
.
n
must be at least zero.
Unchanged on exit.
t
REAL
for
strmvt
DOUBLE PRECISION
for
dtrmvt
COMPLEX
for
ctrmvt
DOUBLE COMPLEX
for
ztrmvt
Array of size (
ldt
,
n
).
Before entry with
uplo
= 'U' or 'u', the leading
n
-by-
n
upper triangular part of the array
t
must contain the upper triangular matrix and the strictly lower triangular part of
t
is not referenced.
Before entry with
uplo
= 'L' or 'l', the leading
n
-by-
n
lower triangular part of the array
t
must contain the lower triangular matrix and the strictly upper triangular part of
t
is not referenced.
ldt
INTEGER.
On entry,
lda
specifies the first dimension of
A
as declared in the calling (sub) program.
lda
must be at least max( 1,
n
).
Unchanged on exit.
incx
INTEGER.
On entry,
incx
specifies the increment for the elements of
x
.
incx
must not be zero.
Unchanged on exit.
y
REAL
for
strmvt
DOUBLE PRECISION
for
dtrmvt
COMPLEX
for
ctrmvt
DOUBLE COMPLEX
for
ztrmvt
Array of size at least ( 1 + (
n
- 1 )*abs(
incy
) ).
Before entry, the incremented array
y
must contain the
n
element vector
y
.
Unchanged on exit.
incy
INTEGER.
On entry,
incy
specifies the increment for the elements of
y
.
incy
must not be zero.
Unchanged on exit.
incw
INTEGER.
On entry,
incw
specifies the increment for the elements of
w
.
incw
must not be zero.
Unchanged on exit.
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