void mexFunction
(
int nargout,
mxArray *pargout [ ],
int nargin,
const mxArray *pargin [ ]
)
{
UF_long i, m, n, *Ap, *Ai, *P, nc, result, spumoni, full ;
double *Pout, *InfoOut, Control [AMD_CONTROL], Info [AMD_INFO], *ControlIn ;
mxArray *A ;
/* --------------------------------------------------------------------- */
/* get control parameters */
/* --------------------------------------------------------------------- */
amd_malloc = mxMalloc ;
amd_free = mxFree ;
amd_calloc = mxCalloc ;
amd_realloc = mxRealloc ;
amd_printf = mexPrintf ;
spumoni = 0 ;
if (nargin == 0)
{
/* get the default control parameters, and return */
pargout [0] = mxCreateDoubleMatrix (AMD_CONTROL, 1, mxREAL) ;
amd_l_defaults (mxGetPr (pargout [0])) ;
if (nargout == 0)
{
amd_l_control (mxGetPr (pargout [0])) ;
}
return ;
}
amd_l_defaults (Control) ;
if (nargin > 1)
{
ControlIn = mxGetPr (pargin [1]) ;
nc = mxGetM (pargin [1]) * mxGetN (pargin [1]) ;
Control [AMD_DENSE]
= (nc > 0) ? ControlIn [AMD_DENSE] : AMD_DEFAULT_DENSE ;
Control [AMD_AGGRESSIVE]
= (nc > 1) ? ControlIn [AMD_AGGRESSIVE] : AMD_DEFAULT_AGGRESSIVE ;
spumoni = (nc > 2) ? (ControlIn [2] != 0) : 0 ;
}
if (spumoni > 0)
{
amd_l_control (Control) ;
}
/* --------------------------------------------------------------------- */
/* get inputs */
/* --------------------------------------------------------------------- */
if (nargout > 2 || nargin > 2)
{
mexErrMsgTxt ("Usage: p = amd (A)\nor [p, Info] = amd (A, Control)") ;
}
A = (mxArray *) pargin [0] ;
n = mxGetN (A) ;
m = mxGetM (A) ;
if (spumoni > 0)
{
mexPrintf (" input matrix A is %d-by-%d\n", m, n) ;
}
if (mxGetNumberOfDimensions (A) != 2)
{
mexErrMsgTxt ("amd: A must be 2-dimensional") ;
}
if (m != n)
{
mexErrMsgTxt ("amd: A must be square") ;
}
/* --------------------------------------------------------------------- */
/* allocate workspace for output permutation */
/* --------------------------------------------------------------------- */
P = mxMalloc ((n+1) * sizeof (UF_long)) ;
/* --------------------------------------------------------------------- */
/* if A is full, convert to a sparse matrix */
/* --------------------------------------------------------------------- */
full = !mxIsSparse (A) ;
if (full)
{
if (spumoni > 0)
{
mexPrintf (
" input matrix A is full (sparse copy of A will be created)\n");
}
mexCallMATLAB (1, &A, 1, (mxArray **) pargin, "sparse") ;
}
Ap = (UF_long *) mxGetJc (A) ;
Ai = (UF_long *) mxGetIr (A) ;
if (spumoni > 0)
{
mexPrintf (" input matrix A has %d nonzero entries\n", Ap [n]) ;
}
/* --------------------------------------------------------------------- */
/* order the matrix */
/* --------------------------------------------------------------------- */
result = amd_l_order (n, Ap, Ai, P, Control, Info) ;
/* --------------------------------------------------------------------- */
/* if A is full, free the sparse copy of A */
/* --------------------------------------------------------------------- */
if (full)
{
mxDestroyArray (A) ;
}
/* --------------------------------------------------------------------- */
/* print results (including return value) */
/* --------------------------------------------------------------------- */
if (spumoni > 0)
{
amd_l_info (Info) ;
}
/* --------------------------------------------------------------------- */
/* check error conditions */
/* --------------------------------------------------------------------- */
if (result == AMD_OUT_OF_MEMORY)
{
mexErrMsgTxt ("amd: out of memory") ;
}
else if (result == AMD_INVALID)
{
mexErrMsgTxt ("amd: input matrix A is corrupted") ;
}
/* --------------------------------------------------------------------- */
/* copy the outputs to MATLAB */
/* --------------------------------------------------------------------- */
/* output permutation, P */
pargout [0] = mxCreateDoubleMatrix (1, n, mxREAL) ;
Pout = mxGetPr (pargout [0]) ;
for (i = 0 ; i < n ; i++)
{
Pout [i] = P [i] + 1 ; /* change to 1-based indexing for MATLAB */
}
mxFree (P) ;
/* Info */
if (nargout > 1)
{
pargout [1] = mxCreateDoubleMatrix (AMD_INFO, 1, mxREAL) ;
InfoOut = mxGetPr (pargout [1]) ;
for (i = 0 ; i < AMD_INFO ; i++)
{
InfoOut [i] = Info [i] ;
}
}
}
int main (void)
#endif
{
/* ---------------------------------------------------------------------- */
/* local variables */
/* ---------------------------------------------------------------------- */
#ifdef USE_AMD
double Info [AMD_INFO] ;
#endif
double r, rnorm, flops, maxrnorm = 0. ;
double *Ax, *Lx, *B, *D, *X, *Y ;
LDL_int matrix, *Ai, *Ap, *Li, *Lp, *P, *Pinv, *Perm, *PermInv, n, i, j, p,
nz, *Flag, *Pattern, *Lnz, *Parent, trial, lnz, d, jumbled ;
FILE *f ;
char s [LEN] ;
/* ---------------------------------------------------------------------- */
/* check the error-checking routines with null matrices */
/* ---------------------------------------------------------------------- */
i = 1 ;
n = -1 ;
if (LDL_valid_perm (n, (LDL_int *) NULL, &i)
|| !LDL_valid_perm (0, (LDL_int *) NULL, &i)
|| LDL_valid_matrix (n, (LDL_int *) NULL, (LDL_int *) NULL)
|| LDL_valid_matrix (0, &i, &i))
{
printf (PROGRAM ": ldl error-checking routine failed\n") ;
EXIT_ERROR ;
}
/* ---------------------------------------------------------------------- */
/* read in a factorize a set of matrices */
/* ---------------------------------------------------------------------- */
for (matrix = 1 ; matrix <= NMATRICES ; matrix++)
{
/* ------------------------------------------------------------------ */
/* read in the matrix and the permutation */
/* ------------------------------------------------------------------ */
sprintf (s, "../Matrix/A%02d", (int) matrix) ;
if ((f = fopen (s, "r")) == (FILE *) NULL)
{
printf (PROGRAM ": could not open file: %s\n", s) ;
EXIT_ERROR ;
}
fgets (s, LEN, f) ;
printf ("\n\n--------------------------------------------------------");
printf ("\nInput matrix: %s", s) ;
printf ("--------------------------------------------------------\n\n");
fscanf (f, LDL_ID " " LDL_ID, &n, &jumbled) ;
n = (n < 0) ? (0) : (n) ;
ALLOC_MEMORY (P, LDL_int, n) ;
ALLOC_MEMORY (Ap, LDL_int, n+1) ;
for (j = 0 ; j <= n ; j++)
{
fscanf (f, LDL_ID, &Ap [j]) ;
}
nz = Ap [n] ;
ALLOC_MEMORY (Ai, LDL_int, nz) ;
ALLOC_MEMORY (Ax, double, nz) ;
for (p = 0 ; p < nz ; p++)
{
fscanf (f, LDL_ID , &Ai [p]) ;
}
for (p = 0 ; p < nz ; p++)
{
fscanf (f, "%lg", &Ax [p]) ;
}
for (j = 0 ; j < n ; j++)
{
fscanf (f, LDL_ID , &P [j]) ;
}
fclose (f) ;
/* ------------------------------------------------------------------ */
/* check the matrix A and the permutation P */
/* ------------------------------------------------------------------ */
ALLOC_MEMORY (Flag, LDL_int, n) ;
/* To test the error-checking routines, some of the input matrices
* are not valid. So this error is expected to occur. */
if (!LDL_valid_matrix (n, Ap, Ai) || !LDL_valid_perm (n, P, Flag))
{
printf (PROGRAM ": invalid matrix and/or permutation\n") ;
FREE_MEMORY (P, LDL_int) ;
FREE_MEMORY (Ap, LDL_int) ;
FREE_MEMORY (Ai, LDL_int) ;
FREE_MEMORY (Ax, double) ;
FREE_MEMORY (Flag, LDL_int) ;
continue ;
}
/* ------------------------------------------------------------------ */
/* get the AMD permutation, if available */
/* ------------------------------------------------------------------ */
#ifdef USE_AMD
/* recompute the permutation with AMD */
/* Assume that AMD produces a valid permutation P. */
#ifdef LDL_LONG
if (amd_l_order (n, Ap, Ai, P, (double *) NULL, Info) < AMD_OK)
{
printf (PROGRAM ": call to AMD failed\n") ;
EXIT_ERROR ;
}
amd_l_control ((double *) NULL) ;
amd_l_info (Info) ;
#else
if (amd_order (n, Ap, Ai, P, (double *) NULL, Info) < AMD_OK)
{
printf (PROGRAM ": call to AMD failed\n") ;
EXIT_ERROR ;
}
amd_control ((double *) NULL) ;
amd_info (Info) ;
#endif
#endif
/* ------------------------------------------------------------------ */
/* allocate workspace and the first part of LDL factorization */
/* ------------------------------------------------------------------ */
ALLOC_MEMORY (Pinv, LDL_int, n) ;
ALLOC_MEMORY (Y, double, n) ;
ALLOC_MEMORY (Pattern, LDL_int, n) ;
ALLOC_MEMORY (Lnz, LDL_int, n) ;
ALLOC_MEMORY (Lp, LDL_int, n+1) ;
ALLOC_MEMORY (Parent, LDL_int, n) ;
ALLOC_MEMORY (D, double, n) ;
ALLOC_MEMORY (B, double, n) ;
ALLOC_MEMORY (X, double, n) ;
/* ------------------------------------------------------------------ */
/* factorize twice, with and without permutation */
/* ------------------------------------------------------------------ */
for (trial = 1 ; trial <= 2 ; trial++)
{
if (trial == 1)
{
printf ("Factorize PAP'=LDL' and solve Ax=b\n") ;
Perm = P ;
PermInv = Pinv ;
}
else
{
printf ("Factorize A=LDL' and solve Ax=b\n") ;
Perm = (LDL_int *) NULL ;
PermInv = (LDL_int *) NULL ;
}
/* -------------------------------------------------------------- */
/* symbolic factorization to get Lp, Parent, Lnz, and Pinv */
/* -------------------------------------------------------------- */
LDL_symbolic (n, Ap, Ai, Lp, Parent, Lnz, Flag, Perm, PermInv) ;
lnz = Lp [n] ;
/* find # of nonzeros in L, and flop count for LDL_numeric */
flops = 0 ;
for (j = 0 ; j < n ; j++)
{
flops += ((double) Lnz [j]) * (Lnz [j] + 2) ;
}
printf ("Nz in L: "LDL_ID" Flop count: %g\n", lnz, flops) ;
/* -------------------------------------------------------------- */
/* allocate remainder of L, of size lnz */
/* -------------------------------------------------------------- */
ALLOC_MEMORY (Li, LDL_int, lnz) ;
ALLOC_MEMORY (Lx, double, lnz) ;
/* -------------------------------------------------------------- */
/* numeric factorization to get Li, Lx, and D */
/* -------------------------------------------------------------- */
d = LDL_numeric (n, Ap, Ai, Ax, Lp, Parent, Lnz, Li, Lx, D,
Y, Flag, Pattern, Perm, PermInv) ;
/* -------------------------------------------------------------- */
/* solve, or report singular case */
/* -------------------------------------------------------------- */
if (d != n)
{
printf ("Ax=b not solved since D("LDL_ID","LDL_ID") is zero.\n", d, d) ;
}
else
{
/* construct the right-hand-side, B */
for (i = 0 ; i < n ; i++)
{
B [i] = 1 + ((double) i) / 100 ;
}
/* solve Ax=b */
if (trial == 1)
{
/* the factorization is LDL' = PAP' */
LDL_perm (n, Y, B, P) ; /* y = Pb */
LDL_lsolve (n, Y, Lp, Li, Lx) ; /* y = L\y */
LDL_dsolve (n, Y, D) ; /* y = D\y */
LDL_ltsolve (n, Y, Lp, Li, Lx) ; /* y = L'\y */
LDL_permt (n, X, Y, P) ; /* x = P'y */
}
else
{
/* the factorization is LDL' = A */
for (i = 0 ; i < n ; i++) /* x = b */
{
X [i] = B [i] ;
}
LDL_lsolve (n, X, Lp, Li, Lx) ; /* x = L\x */
LDL_dsolve (n, X, D) ; /* x = D\x */
LDL_ltsolve (n, X, Lp, Li, Lx) ; /* x = L'\x */
}
/* compute the residual y = Ax-b */
/* note that this code can tolerate a jumbled matrix */
for (i = 0 ; i < n ; i++)
{
Y [i] = -B [i] ;
}
for (j = 0 ; j < n ; j++)
{
for (p = Ap [j] ; p < Ap [j+1] ; p++)
{
Y [Ai [p]] += Ax [p] * X [j] ;
}
}
/* rnorm = norm (y, inf) */
rnorm = 0 ;
for (i = 0 ; i < n ; i++)
{
r = (Y [i] > 0) ? (Y [i]) : (-Y [i]) ;
rnorm = (r > rnorm) ? (r) : (rnorm) ;
}
maxrnorm = (rnorm > maxrnorm) ? (rnorm) : (maxrnorm) ;
printf ("relative maxnorm of residual: %g\n", rnorm) ;
}
/* -------------------------------------------------------------- */
/* free the size-lnz part of L */
/* -------------------------------------------------------------- */
FREE_MEMORY (Li, LDL_int) ;
FREE_MEMORY (Lx, double) ;
}
/* free everything */
FREE_MEMORY (P, LDL_int) ;
FREE_MEMORY (Ap, LDL_int) ;
FREE_MEMORY (Ai, LDL_int) ;
FREE_MEMORY (Ax, double) ;
FREE_MEMORY (Pinv, LDL_int) ;
FREE_MEMORY (Y, double) ;
FREE_MEMORY (Flag, LDL_int) ;
FREE_MEMORY (Pattern, LDL_int) ;
FREE_MEMORY (Lnz, LDL_int) ;
FREE_MEMORY (Lp, LDL_int) ;
FREE_MEMORY (Parent, LDL_int) ;
FREE_MEMORY (D, double) ;
FREE_MEMORY (B, double) ;
FREE_MEMORY (X, double) ;
}
printf ("\nLargest residual during all tests: %g\n", maxrnorm) ;
if (maxrnorm < 1e-8)
{
printf ("\n" PROGRAM ": all tests passed\n") ;
EXIT_OK ;
}
else
{
printf ("\n" PROGRAM ": one more tests failed (residual too high)\n") ;
EXIT_ERROR ;
}
}
int main (void)
{
/* The symmetric can_24 Harwell/Boeing matrix, including upper and lower
* triangular parts, and the diagonal entries. Note that this matrix is
* 0-based, with row and column indices in the range 0 to n-1. */
Long n = 24, nz,
Ap [ ] = { 0, 9, 15, 21, 27, 33, 39, 48, 57, 61, 70, 76, 82, 88, 94, 100,
106, 110, 119, 128, 137, 143, 152, 156, 160 },
Ai [ ] = {
/* column 0: */ 0, 5, 6, 12, 13, 17, 18, 19, 21,
/* column 1: */ 1, 8, 9, 13, 14, 17,
/* column 2: */ 2, 6, 11, 20, 21, 22,
/* column 3: */ 3, 7, 10, 15, 18, 19,
/* column 4: */ 4, 7, 9, 14, 15, 16,
/* column 5: */ 0, 5, 6, 12, 13, 17,
/* column 6: */ 0, 2, 5, 6, 11, 12, 19, 21, 23,
/* column 7: */ 3, 4, 7, 9, 14, 15, 16, 17, 18,
/* column 8: */ 1, 8, 9, 14,
/* column 9: */ 1, 4, 7, 8, 9, 13, 14, 17, 18,
/* column 10: */ 3, 10, 18, 19, 20, 21,
/* column 11: */ 2, 6, 11, 12, 21, 23,
/* column 12: */ 0, 5, 6, 11, 12, 23,
/* column 13: */ 0, 1, 5, 9, 13, 17,
/* column 14: */ 1, 4, 7, 8, 9, 14,
/* column 15: */ 3, 4, 7, 15, 16, 18,
/* column 16: */ 4, 7, 15, 16,
/* column 17: */ 0, 1, 5, 7, 9, 13, 17, 18, 19,
/* column 18: */ 0, 3, 7, 9, 10, 15, 17, 18, 19,
/* column 19: */ 0, 3, 6, 10, 17, 18, 19, 20, 21,
/* column 20: */ 2, 10, 19, 20, 21, 22,
/* column 21: */ 0, 2, 6, 10, 11, 19, 20, 21, 22,
/* column 22: */ 2, 20, 21, 22,
/* column 23: */ 6, 11, 12, 23 } ;
Long P [24], Pinv [24], i, j, k, jnew, p, inew, result ;
double Control [AMD_CONTROL], Info [AMD_INFO] ;
char A [24][24] ;
/* here is an example of how to use AMD_VERSION. This code will work in
* any version of AMD. */
#if defined(AMD_VERSION) && (AMD_VERSION >= AMD_VERSION_CODE(1,2))
printf ("AMD version %d.%d.%d, date: %s\n",
AMD_MAIN_VERSION, AMD_SUB_VERSION, AMD_SUBSUB_VERSION, AMD_DATE) ;
#else
printf ("AMD version: 1.1 or earlier\n") ;
#endif
printf ("AMD demo, with the 24-by-24 Harwell/Boeing matrix, can_24:\n") ;
/* get the default parameters, and print them */
amd_l_defaults (Control) ;
amd_l_control (Control) ;
/* print the input matrix */
nz = Ap [n] ;
printf ("\nInput matrix: %ld-by-%ld, with %ld entries.\n"
" Note that for a symmetric matrix such as this one, only the\n"
" strictly lower or upper triangular parts would need to be\n"
" passed to AMD, since AMD computes the ordering of A+A'. The\n"
" diagonal entries are also not needed, since AMD ignores them.\n"
, n, n, nz) ;
for (j = 0 ; j < n ; j++)
{
printf ("\nColumn: %ld, number of entries: %ld, with row indices in"
" Ai [%ld ... %ld]:\n row indices:",
j, Ap [j+1] - Ap [j], Ap [j], Ap [j+1]-1) ;
for (p = Ap [j] ; p < Ap [j+1] ; p++)
{
i = Ai [p] ;
printf (" %ld", i) ;
}
printf ("\n") ;
}
/* print a character plot of the input matrix. This is only reasonable
* because the matrix is small. */
printf ("\nPlot of input matrix pattern:\n") ;
for (j = 0 ; j < n ; j++)
{
for (i = 0 ; i < n ; i++) A [i][j] = '.' ;
for (p = Ap [j] ; p < Ap [j+1] ; p++)
{
i = Ai [p] ;
A [i][j] = 'X' ;
}
}
printf (" ") ;
for (j = 0 ; j < n ; j++) printf (" %1ld", j % 10) ;
printf ("\n") ;
for (i = 0 ; i < n ; i++)
{
printf ("%2ld: ", i) ;
for (j = 0 ; j < n ; j++)
{
printf (" %c", A [i][j]) ;
}
printf ("\n") ;
}
/* order the matrix */
result = amd_l_order (n, Ap, Ai, P, Control, Info) ;
printf ("return value from amd_l_order: %ld (should be %d)\n",
result, AMD_OK) ;
/* print the statistics */
amd_l_info (Info) ;
if (result != AMD_OK)
{
printf ("AMD failed\n") ;
exit (1) ;
}
/* print the permutation vector, P, and compute the inverse permutation */
printf ("Permutation vector:\n") ;
for (k = 0 ; k < n ; k++)
{
/* row/column j is the kth row/column in the permuted matrix */
j = P [k] ;
Pinv [j] = k ;
printf (" %2ld", j) ;
}
printf ("\n\n") ;
printf ("Inverse permutation vector:\n") ;
for (j = 0 ; j < n ; j++)
{
k = Pinv [j] ;
printf (" %2ld", k) ;
}
printf ("\n\n") ;
/* print a character plot of the permuted matrix. */
printf ("\nPlot of permuted matrix pattern:\n") ;
for (jnew = 0 ; jnew < n ; jnew++)
{
j = P [jnew] ;
for (inew = 0 ; inew < n ; inew++) A [inew][jnew] = '.' ;
for (p = Ap [j] ; p < Ap [j+1] ; p++)
{
inew = Pinv [Ai [p]] ;
A [inew][jnew] = 'X' ;
}
}
printf (" ") ;
for (j = 0 ; j < n ; j++) printf (" %1ld", j % 10) ;
printf ("\n") ;
for (i = 0 ; i < n ; i++)
{
printf ("%2ld: ", i) ;
for (j = 0 ; j < n ; j++)
{
printf (" %c", A [i][j]) ;
}
printf ("\n") ;
}
return (0) ;
}
