Dgemv.java
package org.mklab.sdpj.gpack.blaswrap;
import org.mklab.nfc.matrix.ComplexNumericalMatrix;
import org.mklab.nfc.matrix.RealNumericalMatrix;
import org.mklab.nfc.scalar.ComplexNumericalScalar;
import org.mklab.nfc.scalar.RealNumericalScalar;
/**
* @author takafumi
* @param <RS> 実スカラーの型
* @param <RM> 実行列の型
* @param <CS> 複素スカラーの型
* @param <CM> 複素行列の型
*/
public class Dgemv<RS extends RealNumericalScalar<RS, RM, CS, CM>, RM extends RealNumericalMatrix<RS, RM, CS, CM>, CS extends ComplexNumericalScalar<RS, RM, CS, CM>, CM extends ComplexNumericalMatrix<RS, RM, CS, CM>> {
/* Purpose
=======
DGEMV performs one of the matrix-vector operations
y := alpha*A*x + beta*y, or y := alpha*A'*x + beta*y,
where alpha and beta are scalars, x and y are vectors and A is an
m by n matrix.
Parameters
==========
TRANS - CHARACTER*1.
On entry, TRANS specifies the operation to be performed as
follows:
TRANS = 'N' or 'n' y := alpha*A*x + beta*y.
TRANS = 'T' or 't' y := alpha*A'*x + beta*y.
TRANS = 'C' or 'c' y := alpha*A'*x + beta*y.
Unchanged on exit.
M - INTEGER.
On entry, M specifies the number of rows of the matrix A.
M must be at least zero.
Unchanged on exit.
N - INTEGER.
On entry, N specifies the number of columns of the matrix A.
N must be at least zero.
Unchanged on exit.
ALPHA - DOUBLE PRECISION.
On entry, ALPHA specifies the scalar alpha.
Unchanged on exit.
A - DOUBLE PRECISION array of DIMENSION ( LDA, n ).
Before entry, the leading m by n part of the array A must
contain the matrix of coefficients.
Unchanged on exit.
LDA - INTEGER.
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. LDA must be at least
max( 1, m ).
Unchanged on exit.
X - DOUBLE PRECISION array of DIMENSION at least
( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N' or 'n'
and at least
( 1 + ( m - 1 )*abs( INCX ) ) otherwise.
Before entry, the incremented array X must contain the
vector x.
Unchanged on exit.
INCX - INTEGER.
On entry, INCX specifies the increment for the elements of
X. INCX must not be zero.
Unchanged on exit.
BETA - DOUBLE PRECISION.
On entry, BETA specifies the scalar beta. When BETA is
supplied as zero then Y need not be set on input.
Unchanged on exit.
Y - DOUBLE PRECISION array of DIMENSION at least
( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n'
and at least
( 1 + ( n - 1 )*abs( INCY ) ) otherwise.
Before entry with BETA non-zero, the incremented array Y
must contain the vector y. On exit, Y is overwritten by the
updated vector y.
INCY - INTEGER.
On entry, INCY specifies the increment for the elements of
Y. INCY must not be zero.
Unchanged on exit.
Level 2 Blas routine.
-- Written on 22-October-1986.
Jack Dongarra, Argonne National Lab.
Jeremy Du Croz, Nag Central Office.
Sven Hammarling, Nag Central Office.
Richard Hanson, Sandia National Labs.
Test the input parameters.
Parameter adjustments */
/**
* y=alpha*a*x+beta*y or y=alpha*a'*x+beta*y
*
* @param trans unchanged
* @param m unchanged Aの行数
* @param n unchanged Aの列数
* @param alpha unchanged
* @param a unchanged matrix A
* @param lda unchanged
* @param x unchanged vector X
* @param incx unchanged
* @param beta unchanged
* @param y is overwritten by the update vector y
* @param incy unchanged
* @return result
*/
public int execute(String trans, int m, int n, RS alpha, RS[] a, int lda, RS[] x, int incx, RS beta, RS[] y, int incy) {
final RS unit = a[0].createUnit();
int a_dim1 = lda;
int a_offset = 1 + a_dim1 * 1;
int pointer_a = -a_offset;
int info = 0;
if (!BLAS.lsame(trans, "N") && !BLAS.lsame(trans, "T") && !BLAS.lsame(trans, "C")) { //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
info = 1;
} else if (m < 0) {
info = 2;
} else if (n < 0) {
info = 3;
} else if (lda < Math.max(1, m)) {
info = 6;
} else if (incx == 0) {
info = 8;
} else if (incy == 0) {
info = 11;
}
if (info != 0) {
BLAS.xerbla("DGEMV ", info); //$NON-NLS-1$
return 0;
}
// Quick return if possible.
if (m == 0 || n == 0 || alpha.isZero() && beta.isZero()) {
return 0;
}
// Set LENX and LENY, the lengths of the vectors x and y, and set up the start points in X and Y. */
int lenx;
int leny;
if (BLAS.lsame(trans, "N")) { //$NON-NLS-1$
lenx = n;
leny = m;
} else {
lenx = m;
leny = n;
}
int kx;
if (incx > 0) {
kx = 1;
} else {
kx = 1 - (lenx - 1) * incx;
}
int ky;
if (incy > 0) {
ky = 1;
} else {
ky = 1 - (leny - 1) * incy;
}
/* Start the operations. In this version the elements of A are
* accessed sequentially with one pass through A.
* First form y := beta*y.
*/
if (!beta.equals(unit.createUnit())) {
if (incy == 1) {
if (beta.isZero()) {
for (int i = 1; i <= leny; ++i) {
y[i - 1] = unit.createZero();
}
} else {
for (int i = 1; i <= leny; ++i) {
y[i - 1] = beta.multiply(y[i - 1]);
}
}
} else {
int iy = ky;
if (beta.isZero()) {
for (int i = 1; i <= leny; ++i) {
y[iy - 1] = unit.createZero();
iy += incy;
}
} else {
for (int i = 1; i <= leny; ++i) {
y[iy - 1] = beta.multiply(y[iy - 1]);
iy += incy;
}
}
}
}
if (alpha.isZero()) {
return 0;
}
if (BLAS.lsame(trans, "N")) { //$NON-NLS-1$
// Form y := alpha*A*x + y.
int jx = kx;
if (incy == 1) {
for (int j = 1; j <= n; ++j) {
if (!x[jx - 1].isZero()) {
RS temp = alpha.multiply(x[jx - 1]);
for (int i = 1; i <= m; ++i) {
y[i - 1] = y[i - 1].add(temp.multiply(a[j * a_dim1 + i + pointer_a]));
}
}
jx += incx;
}
} else {
for (int j = 1; j <= n; ++j) {
if (!x[jx - 1].isZero()) {
RS temp = alpha.multiply(x[jx - 1]);
int iy = ky;
for (int i = 1; i <= m; ++i) {
y[iy - 1] = y[iy - 1].add(temp.multiply(a[j * a_dim1 + i + pointer_a]));
iy += incy;
}
}
jx += incx;
}
}
} else {
// Form y := alpha*A'*x + y.
int jy = ky;
if (incx == 1) {
for (int j = 1; j <= n; ++j) {
RS temp = unit.createZero();
for (int i = 1; i <= m; ++i) {
temp = temp.add(a[j * a_dim1 + i + pointer_a].multiply(x[i - 1]));
}
y[jy - 1] = y[jy - 1].add(alpha.multiply(temp));
jy += incy;
}
} else {
for (int j = 1; j <= n; ++j) {
RS temp = unit.createZero();
int ix = kx;
for (int i = 1; i <= m; ++i) {
temp = temp.add(a[j * a_dim1 + i + pointer_a].multiply(x[ix - 1]));
ix += incx;
}
y[jy - 1] = y[jy - 1].add(alpha.multiply(temp));
jy += incy;
}
}
}
return 0;
}
}