xref: /petsc/src/mat/impls/shell/shell.c (revision f0479e8c2158d05ab5c06def5bd82110ef658075)
1 
2 /*
3    This provides a simple shell for Fortran (and C programmers) to
4   create a very simple matrix class for use with KSP without coding
5   mush of anything.
6 */
7 
8 #include "petsc.h"
9 #include "matimpl.h"        /*I "mat.h" I*/
10 #include "vec/vecimpl.h"
11 
12 typedef struct {
13   int  m,n;
14   int  (*mult)(void *,Vec,Vec);
15   int  (*multtransadd)(void*,Vec,Vec,Vec);
16   void *ctx;
17 } MatShell;
18 
19 static int MatShellMult(Mat mat,Vec x,Vec y)
20 {
21   MatShell *shell;
22   shell = (MatShell *) mat->data;
23   return (*shell->mult)(shell->ctx,x,y);
24 }
25 static int MatShellMultTransAdd(Mat mat,Vec x,Vec y,Vec z)
26 {
27   MatShell *shell;
28   shell = (MatShell *) mat->data;
29   return (*shell->multtransadd)(shell->ctx,x,y,z);
30 }
31 static int MatShellDestroy(PetscObject obj)
32 {
33   Mat      mat = (Mat) obj;
34   MatShell *shell;
35   shell = (MatShell *) mat->data;
36   FREE(shell); FREE(mat);
37   return 0;
38 }
39 
40 static struct _MatOps MatOps = {0,0,
41        0,
42        MatShellMult,0,0,MatShellMultTransAdd,
43        0,0,0,0,
44        0,0,
45        0,
46        0,
47        0,0,0,
48        0,
49        0,0,0,
50        0,0,
51        0,
52        0,0,0,0,
53        0,0 };
54 
55 /*@
56    MatShellCreate - creates a new matrix class for use with your
57           own private data storage format. This is intended to
58           provide a simple class to use with KSP. You should
59           not use this if you plan to make a complete class.
60 
61   Input Parameters:
62 .  m,n - number of rows and columns in matrix
63 .  ctx - pointer to your data needed by matrix multiply.
64 
65   Output Parameters:
66 .  mat - the matrix
67 
68   Keywords: matrix, shell
69 
70   Usage:
71 .             int (*mult)(void *,Vec,Vec);
72 .             MatShellCreate(m,n,ctx,&mat);
73 .             MatShellSetMult(mat,mult);
74 
75 @*/
76 int MatShellCreate(int m, int n, void *ctx,Mat *mat)
77 {
78   Mat      newmat;
79   MatShell *shell;
80   CREATEHEADER(newmat,_Mat);
81   *mat           = newmat;
82   newmat->cookie = MAT_COOKIE;
83   newmat->factor = 0;
84   newmat->row    = 0;
85   newmat->col    = 0;
86   newmat->destroy= MatShellDestroy;
87   newmat->ops    = &MatOps;
88   shell          = NEW(MatShell); CHKPTR(shell);
89   newmat->data   = (void *) shell;
90   shell->mult    = 0;
91   shell->m       = m;
92   shell->n       = n;
93   shell->ctx     = ctx;
94   return 0;
95 }
96 
97 /*@
98    MatShellSetMult - sets routine to use as matrix vector multiply.
99 
100   Input Parameters:
101 .  mat - the matrix to add the operation to, created with MatShellCreate()
102 .  mult - the matrix vector multiply routine.
103 
104   Keywords: matrix, multiply
105 @*/
106 int MatShellSetMult(Mat mat, int (*mult)(void*,Vec,Vec))
107 {
108   MatShell *shell;
109   VALIDHEADER(mat,MAT_COOKIE);
110   shell = (MatShell *) mat->data;
111   shell->mult = mult;
112   return 0;
113 }
114 /*@
115    MatShellSetMultTransAdd - sets routine to use as matrix vector multiply.
116 
117   Input Parameters:
118 .  mat - the matrix to add the operation to, created with MatShellCreate()
119 .  mult - the matrix vector multiply routine.
120 
121   Keywords: matrix, multiply, transpose
122 @*/
123 int MatShellSetMultTransAdd(Mat mat, int (*mult)(void*,Vec,Vec,Vec))
124 {
125   MatShell *shell;
126   VALIDHEADER(mat,MAT_COOKIE);
127   shell               = (MatShell *) mat->data;
128   shell->multtransadd = mult;
129   return 0;
130 }
131 
132 
133