---
title: KmlScaissGmresSubPcSet?I?
description: "设置迭代求解的block jacobi中子预条件子相关参数。"
url: https://www.hikunpeng.com/document/detail/zh/kunpenghpcs/hpckit/devg/kunpengaccel_kml_0942.html
sourcePath: /source/zh/kunpenghpcs/hpckit/devg/kunpengaccel_kml_0942.html
indexId: bb363fa7845abcabcc9c411806302ade747eabbffec566fcf21624db773b5e0061
---
# KmlScaissGmresSubPcSet?I?

设置迭代求解的block jacobi中子预条件子相关参数。

#### 接口定义

C Interface：

int KmlScaissGmresSubPcSetSII(KmlScasolverTask **handle, enum KmlSolverPreconditionerParam param, int subn, const int *data, int nd);

int KmlScaissGmresSubPcSetDII(KmlScasolverTask **handle, enum KmlSolverPreconditionerParam param, int subn, const int *data, int nd);

int KmlScaissGmresSubPcSetSIS(KmlScasolverTask **handle, enum KmlSolverPreconditionerParam param, int subn, const float *data, int nd);

int KmlScaissGmresSubPcSetDID(KmlScasolverTask **handle, enum KmlSolverPreconditionerParam param, int subn, const double *data, int nd);


#### 参数

| 参数名 | 类型 | 描述 | 输入/输出 |
| --- | --- | --- | --- |
| handle | KmlScasolverTask \*\* | 求解器句柄，传入之前步骤的变量。 | 输入/输出 |
| param | enum KmlSolverParam | KML\_RELAXATION\_FACTOR表示SOR预条件子相关参数。 KMLSS\_DROP\_FILL表示ILUT预条件子每行最多保留元素个数。 KMLSS\_DROP\_TOL表示ILUT预条件子保留元素的阈值。 | 输入 |
| subn | 在KmlScaissGmresSubPcSetSIS、KmlScaissGmresSubPcSetSII、KmlScaissGmresSubPcSetDII、KmlScaissGmresSubPcSetDID中为int。 | 子预条件子索引。 | 输入 |
| data | 在KmlScaissGmresSubPcSetSII、KmlScaissGmresSubPcSetDII中为const int \*。 在KmlScaissGmresSubPcSetSIS中为const float \*。 在KmlScaissGmresSubPcSetDID中为const double \*。 | 预条件子相关参数。 | 输入 |
| nd | 在KmlScaissGmresSubPcSetSII、KmlScaissGmresSubPcSetSIS、KmlScaissGmresSubPcSetDII、KmlScaissGmresSubPcSetDID中为int。 | data数组元素个数。 | 输入 |


#### 返回值

| 返回值 | 类型 | 描述 |
| --- | --- | --- |
| KMLSS\_NO\_ERROR | int | 正常执行。 |
| KMLSS\_DATA\_SIZE | int | 参数nd不等于1。 |
| KMLSS\_NULL\_ARGUMENT | int | handle，data中存在空参数。 |
| KMLSS\_BAD\_SELECTOR | int | param为无效参数。 |
| KMLSS\_BAD\_PRECONDITIONER | int | 选择的预条件子暂未实现。 |


#### 依赖

#include "kml_scaiss.h"


#### 示例

C Interface：
```
MPI_Init(NULL, NULL);
int size, rank;
MPI_Comm_size(MPI_COMM_WORLD, &size);//获取总进程数
MPI_Comm_rank(MPI_COMM_WORLD, &rank);//获取当前进程标识
int mat_size = 8;
int n = mat_size / size;
int n_beg = n * rank;
if (n * size != mat_size && rank == (size - 1)) {
n = mat_size - n * rank;
}
int ja[26] = { 0, 3, 4, 1, 2, 3, 5, 1, 2, 7, 0, 1, 3, 6, 0, 4, 5, 1, 4, 5, 7, 3, 6, 2, 5, 7 };
double a[26] = { 1.0, 1.0, 2.0, 9.0, 2.0, 1.0, -3.0, 2.0, 3.0, 2.0, 1.0, 1.0, 9.0, -5.0, 2.0, 6.0, 1.0, -3.0, 1.0, 4.0, 1.0, -5.0, 7.0, 2.0, 1.0, 2.0 };
int ia[9] = { 0, 3, 7, 10, 14, 17, 21, 23, 26 };
int a_beg = ia[n_beg];
for (int i = n_beg; i < (n_beg + n + 1); i++) {
ia[i] -= a_beg;
}
/* Internal KML_SCAISS structure */
KmlScasolverTask *handle;
/* KML_SCAISS control parameters */
int error;            /* Output error handle */
/* Create data structures */
const double *a_holder = &a[a_beg];
const int *ja_holder = &ja[a_beg];
const int *ia_holder = &ia[n_beg];
error = KmlScaissGmresInitStripesDI(&handle, mat_size, 1, &n, &n_beg, &a_holder, &ja_holder, &ia_holder, MPI_COMM_WORLD);
double eps = 1e-4;
error = KmlScaissGmresSetDID(&handle, KMLSS_THRESHOLD, &eps, 1);
if (error != 0) {
printf("\nERROR in KmlScaissGmresSetDID with KMLSS_THRESHOLD: %d", error);
return 1;
}
int max_iters = 2000;
error = KmlScaissGmresSetDII(&handle, KMLSS_MAX_ITERATION_COUNT, &max_iters, 1);
if (error != 0) {
printf("\nERROR in KmlScaissGmresSetDII with KMLSS_MAX_ITERATION_COUNT: %d", error);
return 1;
}
int precond = KMLSS_BJACOBI;
error = KmlScaissGmresSetDII(&handle, KMLSS_PRECONDITIONER_TYPE, &precond, 1);
if (error != 0) {
printf("\nERROR in KmlScaissGmresSetDII with KMLSS_PRECONDITIONER_TYPE: %d", error);
return 1;
}
int num_blocks = 1;
error = KmlScaissGmresPcSetDII(&handle, KMLSS_NUM_BLOCKS, &num_blocks, 1);
if (error != 0) {
printf("ERROR in KmlScaissGmresPcSetDII: %d\n", error);
return 1;
}
int subprecond = KMLSS_ICC;
error = KmlScaissGmresPcSetDII(&handle, KMLSS_BLOCK_METHOD, &subprecond, 1);
if (error != 0) {
printf("ERROR in KmlScaissGmresPcSetDII: %d\n", error);
return 1;
}
```