Developer Reference

Contents

p?lacon

Estimates the 1-norm of a square matrix, using the reverse communication for evaluating matrix-vector products.

Syntax

void
pslacon
(
MKL_INT
*n
,
float
*v
,
MKL_INT
*iv
,
MKL_INT
*jv
,
MKL_INT
*descv
,
float
*x
,
MKL_INT
*ix
,
MKL_INT
*jx
,
MKL_INT
*descx
,
MKL_INT
*isgn
,
float
*est
,
MKL_INT
*kase
);
void
pdlacon
(
MKL_INT
*n
,
double
*v
,
MKL_INT
*iv
,
MKL_INT
*jv
,
MKL_INT
*descv
,
double
*x
,
MKL_INT
*ix
,
MKL_INT
*jx
,
MKL_INT
*descx
,
MKL_INT
*isgn
,
double
*est
,
MKL_INT
*kase
);
void
pclacon
(
MKL_INT
*n
,
MKL_Complex8
*v
,
MKL_INT
*iv
,
MKL_INT
*jv
,
MKL_INT
*descv
,
MKL_Complex8
*x
,
MKL_INT
*ix
,
MKL_INT
*jx
,
MKL_INT
*descx
,
float
*est
,
MKL_INT
*kase
);
void
pzlacon
(
MKL_INT
*n
,
MKL_Complex16
*v
,
MKL_INT
*iv
,
MKL_INT
*jv
,
MKL_INT
*descv
,
MKL_Complex16
*x
,
MKL_INT
*ix
,
MKL_INT
*jx
,
MKL_INT
*descx
,
double
*est
,
MKL_INT
*kase
);
Include Files
  • mkl_scalapack.h
Description
The
p?lacon
function
estimates the 1-norm of a square, real/unitary distributed matrix
A
. Reverse communication is used for evaluating matrix-vector products.
x
and
v
are aligned with the distributed matrix
A
, this information is implicitly contained within
iv
,
ix
,
descv
, and
descx
.
Input Parameters
n
(global) The length of the distributed vectors
v
and
x. n
0.
v
(local).
Pointer into the local memory to an array of size
LOCr
(
n
+mod(
iv
-1,
mb_v
)). On the final return,
v
=
a
*
w
, where
est
= norm(
v
)/norm(
w
) (
w
is not returned).
iv
,
jv
(global) The row and column indices in the global matrix
V
indicating the first row and the first column of the submatrix
V
, respectively.
descv
(global and local) array of size
dlen_
. The array descriptor for the distributed matrix V.
x
(local).
Pointer into the local memory to an array of size
LOCr
(
n
+mod(
ix
-1,
mb_x
)).
ix
,
jx
(global) The row and column indices in the global matrix
X
indicating the first row and the first column of the submatrix
X
, respectively.
descx
(global and local) array of size
dlen_
. The array descriptor for the distributed matrix X.
isgn
(local).
Array of size
LOCr
(
n
+mod(
ix
-1,
mb_x
)).
isgn
is aligned with
x
and
v
.
kase
(local).
On the initial call to
p?lacon
,
kase
should be 0.
Output Parameters
x
(local).
On an intermediate return, X should be overwritten by
A
*
X
, if
kase
=1,
A'
*
X
, if
kase
=2,
p?lacon
must be re-called with all the other parameters unchanged.
est
(global).
kase
(local)
On an intermediate return,
kase
is 1 or 2, indicating whether
X
should be overwritten by
A
*
X,
or
A'
*
X
. On the final return from
p?lacon
,
kase
is again 0.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.