·  Home
+   man pages
 -> Linux -> FreeBSD -> OpenBSD -> NetBSD -> Tru64 Unix -> HP-UX 11i -> IRIX
·  Linux HOWTOs
·  FreeBSD Tips
·  *niX Forums

man pages->IRIX man pages -> complib/dpttrs (3)
 Title
 Content
 Arch
 Section All Sections 1 - General Commands 2 - System Calls 3 - Subroutines 4 - Special Files 5 - File Formats 6 - Games 7 - Macros and Conventions 8 - Maintenance Commands 9 - Kernel Interface n - New Commands

### Contents

```
DPTTRS(3F)							    DPTTRS(3F)

```

### NAME[Toc][Back]

```     DPTTRS - solve a system of	linear equations A * X = B with	a symmetric
positive definite tridiagonal matrix A using the factorization A =
L*D*L**T or A = U**T*D*U computed by DPTTRF
```

### SYNOPSIS[Toc][Back]

```     SUBROUTINE	DPTTRS(	N, NRHS, D, E, B, LDB, INFO )

INTEGER	INFO, LDB, N, NRHS

DOUBLE		PRECISION B( LDB, * ), D( * ), E( * )
```

### PURPOSE[Toc][Back]

```     DPTTRS solves a system of linear equations	A * X =	B with a symmetric
positive definite tridiagonal matrix A using the factorization A =
L*D*L**T or A = U**T*D*U computed by DPTTRF.  (The	two forms are
equivalent	if A is	real.)

```

### ARGUMENTS[Toc][Back]

```     N	     (input) INTEGER
The order of the tridiagonal matrix A.  N >= 0.

NRHS    (input) INTEGER
The number	of right hand sides, i.e., the number of columns of
the matrix	B.  NRHS >= 0.

D	     (input) DOUBLE PRECISION array, dimension (N)
The n diagonal elements of	the diagonal matrix D from the
factorization computed by DPTTRF.

E	     (input) DOUBLE PRECISION array, dimension (N-1)
The (n-1) off-diagonal elements of	the unit bidiagonal factor U
or	L from the factorization computed by DPTTRF.

B	     (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
On	entry, the right hand side matrix B.  On exit, the solution
matrix X.

LDB     (input) INTEGER
The leading dimension of the array	B.  LDB	>= max(1,N).

INFO    (output) INTEGER
= 0:  successful exit
< 0:  if INFO = -i, the i-th argument had an illegal value
DPTTRS(3F)							    DPTTRS(3F)

```

### NAME[Toc][Back]

```     DPTTRS - solve a system of	linear equations A * X = B with	a symmetric
positive definite tridiagonal matrix A using the factorization A =
L*D*L**T or A = U**T*D*U computed by DPTTRF
```

### SYNOPSIS[Toc][Back]

```     SUBROUTINE	DPTTRS(	N, NRHS, D, E, B, LDB, INFO )

INTEGER	INFO, LDB, N, NRHS

DOUBLE		PRECISION B( LDB, * ), D( * ), E( * )
```

### PURPOSE[Toc][Back]

```     DPTTRS solves a system of linear equations	A * X =	B with a symmetric
positive definite tridiagonal matrix A using the factorization A =
L*D*L**T or A = U**T*D*U computed by DPTTRF.  (The	two forms are
equivalent	if A is	real.)

```

### ARGUMENTS[Toc][Back]

```     N	     (input) INTEGER
The order of the tridiagonal matrix A.  N >= 0.

NRHS    (input) INTEGER
The number	of right hand sides, i.e., the number of columns of
the matrix	B.  NRHS >= 0.

D	     (input) DOUBLE PRECISION array, dimension (N)
The n diagonal elements of	the diagonal matrix D from the
factorization computed by DPTTRF.

E	     (input) DOUBLE PRECISION array, dimension (N-1)
The (n-1) off-diagonal elements of	the unit bidiagonal factor U
or	L from the factorization computed by DPTTRF.

B	     (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
On	entry, the right hand side matrix B.  On exit, the solution
matrix X.

LDB     (input) INTEGER
The leading dimension of the array	B.  LDB	>= max(1,N).

INFO    (output) INTEGER
= 0:  successful exit
< 0:  if INFO = -i, the i-th argument had an illegal value

PPPPaaaaggggeeee 1111```
[ Back ]
Similar pages