---
title: cmmag
description: "复数矩阵的求模长运算。"
url: https://www.hikunpeng.com/document/detail/zh/kunpengaccel/system-lib/ug-kvsip/kunpengaccel_kvsip_06_0078.html
sourcePath: /source/zh/kunpengaccel/system-lib/ug-kvsip/kunpengaccel_kvsip_06_0078.html
indexId: b1c10f6341c1249aea7a3683a0be8ea5b3d61c4b96d2c3747a73ca543dbe120875
---
# cmmag

复数矩阵的求模长运算。

函数接口声明如下：

float型函数操作：

void (vsip_cmmag_f)(const vsip_cmview_f *a, const vsip_mview_f *r);

#### 参数

| 参数名 | 描述 | 取值范围 | 输入/输出 |
| --- | --- | --- | --- |
| a | 指向源复数矩阵的指针。 | 非空 | 输入 |
| r | 指向目标实数矩阵的指针。 | 非空 | 输出 |


#### 异常输入

空指针输入时，函数直接返回。


#### 示例

```
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include "kvsip.h"
#include "vsip.h"
#include "vsip_type.h"

void CmmagExample()
{
    int32_t row = 4;
    int32_t col = 3;
    int64_t rowStride = 1;
    int64_t colStride = row * rowStride;
    uint64_t offset = 0;
    int32_t srcLen = 2 * (col * colStride + offset);
    int32_t dstLen = col * colStride + offset;
    float *src = (float *)malloc(srcLen * sizeof(float));
    float *dst = (float *)malloc(dstLen * sizeof(float));
    for (int32_t i = 0; i < srcLen; ++i) {
        src[i] = i / 10.0f;
    }

    vsip_cblock_f *block_a = vsip_cblockbind_f(src, NULL, srcLen, VSIP_MEM_NONE);
    vsip_block_f *block_r = vsip_blockbind_f(dst, dstLen, VSIP_MEM_NONE);

    vsip_cmview_f *a = vsip_cmbind_f(block_a, offset, colStride, col, rowStride, row);
    vsip_cblockadmit_f(block_a, VSIP_TRUE);
    vsip_mview_f *r = vsip_mbind_f(block_r, offset, colStride, col, rowStride, row);
    vsip_blockadmit_f(block_r, VSIP_TRUE);

    vsip_cmmag_f(a, r);

    vsip_cmalldestroy_f(a);
    vsip_malldestroy_f(r);

    printf("src:\n");
    for (int32_t i = 0; i < col; ++i) {
        for (int32_t j = 0; j < row; ++j) {
            printf("%.5f ", src[i * row * 2 + j * 2]);
            printf("%.5f    ", src[i * row * 2 + j * 2 + 1]);
        }
        printf("\n");
    }
    printf("\ndst:\n");
    for (int32_t i = 0; i < col; ++i) {
        for (int32_t j = 0; j < row; ++j) {
            printf("%.5f    ", dst[i * row + j]);
        }
        printf("\n");
    }
    free(src);
    free(dst);
}

int main(void) {
    CmmagExample();
    return 0;
}
```

运行结果：

```
src:
0.00000 0.10000    0.20000 0.30000    0.40000 0.50000    0.60000 0.70000
0.80000 0.90000    1.00000 1.10000    1.20000 1.30000    1.40000 1.50000
1.60000 1.70000    1.80000 1.90000    2.00000 2.10000    2.20000 2.30000

dst:
0.10000    0.36056    0.64031    0.92195
1.20416    1.48661    1.76918    2.05183
2.33452    2.61725    2.90000    3.18277
```