純c語言優(yōu)雅地實現(xiàn)矩陣運算庫的方法
編程既是技術(shù)輸出也是藝術(shù)創(chuàng)作。鑒賞高手寫的程序,往往讓人眼前一亮,他們思路、邏輯清晰,所呈現(xiàn)的代碼簡潔、優(yōu)雅、高效,令人為之嘆服。爛代碼則像“屎山"一般讓人作嘔,軟件難以維護(hù)最大的原因除了需求模糊的客觀因素,最重要的主觀因素還是代碼寫得爛。有生之年,愿能保持對編程的熱情,不斷提升編程能力,真正體會其樂趣,共勉!
1.一個優(yōu)雅好用的c語言庫必須滿足哪些條件
這里給出的軟件開發(fā)應(yīng)遵循的一般原則,摘自Les Piegl和Wayne Tiller所著的一本非常經(jīng)典的書The NURBS Book(Second Edition)。
(1)工具性(toolability):應(yīng)該使用可用的工具來建立新的應(yīng)用程序;
(2)可移植性(portability):應(yīng)用程序應(yīng)該容易被移植到不同的軟件和硬件平臺;
(3)可重用性(reusability):程序的編寫應(yīng)該便于重復(fù)使用代碼段;
(4)可檢驗性(testability):程序應(yīng)該簡單一致,以便于測試和調(diào)試;
(5)可靠性(reliability):對程序運行過程中可能出現(xiàn)的各種錯誤應(yīng)該進(jìn)行合理、一致的處理,以使系統(tǒng)穩(wěn)定、可靠;
(6)可擴(kuò)展性(enhanceability):代碼必須易于理解,以便可以容易地增加新的功能;
(7)可維護(hù)性(fixability):易于找出程序錯誤的位置;
(8)一致性(consistency):在整個庫中,編程習(xí)慣應(yīng)保持一致;
(9)可讀性(communicability):程序應(yīng)該易于閱讀和理解;
(10)編程風(fēng)格(style of programming):代碼看起來像書上的數(shù)學(xué)公式那樣以便于讀者理解,同時遵循用戶友好的編程風(fēng)格;
(11)易用性(usability):應(yīng)該使一些非專業(yè)的用戶也能夠方便地使用所開發(fā)的庫來開發(fā)各種更高層次的應(yīng)用程序;
(12)數(shù)值高效性(numerical efficiency):所有函數(shù)必須仔細(xì)推敲,保證其數(shù)值高效性;
(13)基于對象編程(object based programming):避免在函數(shù)間傳遞大量數(shù)據(jù),并且使代碼易于理解。
2.實現(xiàn)一個矩陣運算庫的幾點思考
(1)采用預(yù)定義的數(shù)據(jù)類型,避免直接使用編譯器定義的數(shù)據(jù)類型
typedef unsigned int ERROR_ID; typedef int INDEX; typedef short FLAG; typedef int INTEGER; typedef double REAL; typedef char* STRING; typedef void VOID;
使用預(yù)定義的數(shù)據(jù)類型,有利于程序移植,且可以提高可讀性。例如,如果一個系統(tǒng)只支持單精度浮點數(shù),那么只需修改數(shù)據(jù)類型REAL為float,達(dá)到一勞永逸的效果。定義INDEX與INTEGER數(shù)據(jù)類型是為了在編程時區(qū)分索引變量與普通整形變量,同樣提高可讀性。
(2)基于對象編程,定義矩陣對象
typedef struct matrix { INTEGER rows; INTEGER columns; REAL* p; }MATRIX;
這里,用一級指針而非二級指針指向矩陣的數(shù)據(jù)內(nèi)存地址,有諸多原因,詳見博文:為什么我推薦使用一級指針創(chuàng)建二維數(shù)組?。
(3)除了特別編寫的內(nèi)存處理函數(shù)(使用棧鏈表保存、釋放動態(tài)分配的內(nèi)存地址),不允許任何函數(shù)直接分配和釋放內(nèi)存
不恰當(dāng)?shù)姆峙?、使用與釋放內(nèi)存很可能導(dǎo)致內(nèi)存泄漏、系統(tǒng)崩潰等致命的錯誤。如果一個函數(shù)需動態(tài)申請多個內(nèi)存,那么可能會寫出這樣啰嗦的程序:
double* x = NULL, * y = NULL, * z = NULL; x = (double*)malloc(n1 * sizeof(double)); if (x == NULL) return -1; y = (double*)malloc(n2 * sizeof(double)); if (y == NULL) { free(x); x = NULL; return -1; } z = (double*)malloc(n3 * sizeof(double)); if (z == NULL) { free(x); x = NULL; free(y); y = NULL; return -1; }
為了優(yōu)雅地實現(xiàn)動態(tài)內(nèi)存分配與釋放,Les Piegl大神分3步來處理內(nèi)存申請與釋放:
a)在進(jìn)入一個新的程序時,一個內(nèi)存堆棧被初始化為空;
b)當(dāng)需要申請內(nèi)存時,調(diào)用特定的函數(shù)來分配所需的內(nèi)存,并將指向內(nèi)存的指針存入堆棧中的正確位置;
c)在離開程序時,遍歷內(nèi)存堆棧,釋放其中的指針?biāo)赶虻膬?nèi)存。
程序結(jié)構(gòu)大致如下:
STACKS S; MATRIX* m = NULL; INTEGER rows = 3, columns = 4; ERROR_ID errorID = _ERROR_NO_ERROR; init_stack(&S); m = creat_matrix(rows, columns, &errorID, &S); if (m == NULL) goto EXIT; //do something // ... EXIT: free_stack(&S); return errorID;
(4)防御性編程,對輸入?yún)?shù)做有效性檢查,并返回錯誤號
例如輸入的矩陣行數(shù)、列數(shù)應(yīng)該是正整數(shù),指針參數(shù)必須非空等等。
(5)注意編程細(xì)節(jié)的打磨
a)操作符(逗號,等號等)兩邊必須空一格;
b)邏輯功能相同的程序間不加空行,邏輯功能獨立的程序間加空行;
c)條件判斷關(guān)鍵字(for if while等)后必須加一空格,起到強(qiáng)調(diào)作用,也更清晰;
d)函數(shù)內(nèi)部定義局部變量后,必須空一行后再編寫函數(shù)主體。
3.完整c程序
本矩陣運算庫只包含了矩陣的基本運算,包括創(chuàng)建任意二維/三維矩陣、創(chuàng)建零矩陣及單位矩陣、矩陣加法、矩陣減法、矩陣乘法、矩陣求逆、矩陣轉(zhuǎn)置、矩陣的跡、矩陣LUP分解、解矩陣方程AX=B。
common.h
/******************************************************************************* * File Name : common.h * Library/Module Name : MatrixComputation * Author : Marc Pony(marc_pony@163.com) * Create Date : 2021/6/28 * Abstract Description : 矩陣運算庫公用頭文件 *******************************************************************************/ #ifndef __COMMON_H__ #define __COMMON_H__ /******************************************************************************* * (1)Debug Switch Section *******************************************************************************/ /******************************************************************************* * (2)Include File Section *******************************************************************************/ #include <math.h> #include <stdio.h> #include <malloc.h> #include <stdlib.h> #include <time.h> #include <memory.h> /******************************************************************************* * (3)Macro Define Section *******************************************************************************/ #define _IN #define _OUT #define _IN_OUT #define MAX(x,y) (x) > (y) ? (x) : (y) #define MIN(x,y) (x) < (y) ? (x) : (y) #define _CRT_SECURE_NO_WARNINGS #define PI 3.14159265358979323846 #define POSITIVE_INFINITY 999999999 #define NEGATIVE_INFINITY -999999999 #define _ERROR_NO_ERROR 0X00000000 //無錯誤 #define _ERROR_FAILED_TO_ALLOCATE_HEAP_MEMORY 0X00000001 //分配堆內(nèi)存失敗 #define _ERROR_SVD_EXCEED_MAX_ITERATIONS 0X00000002 //svd超過最大迭代次數(shù) #define _ERROR_MATRIX_ROWS_OR_COLUMNS_NOT_EQUAL 0X00000003 //矩陣行數(shù)或列數(shù)不相等 #define _ERROR_MATRIX_MULTIPLICATION 0X00000004 //矩陣乘法錯誤(第一個矩陣的列數(shù)不等于第二個矩陣行數(shù)) #define _ERROR_MATRIX_MUST_BE_SQUARE 0X00000005 //矩陣必須為方陣 #define _ERROR_MATRIX_NORM_TYPE_INVALID 0X00000006 //矩陣模類型無效 #define _ERROR_MATRIX_EQUATION_HAS_NO_SOLUTIONS 0X00000007 //矩陣方程無解 #define _ERROR_MATRIX_EQUATION_HAS_INFINITY_MANNY_SOLUTIONS 0X00000008 //矩陣方程有無窮多解 #define _ERROR_QR_DECOMPOSITION_FAILED 0X00000009 //QR分解失敗 #define _ERROR_CHOLESKY_DECOMPOSITION_FAILED 0X0000000a //cholesky分解失敗 #define _ERROR_IMPROVED_CHOLESKY_DECOMPOSITION_FAILED 0X0000000b //improved cholesky分解失敗 #define _ERROR_LU_DECOMPOSITION_FAILED 0X0000000c //LU分解失敗 #define _ERROR_CREATE_MATRIX_FAILED 0X0000000d //創(chuàng)建矩陣失敗 #define _ERROR_MATRIX_TRANSPOSE_FAILED 0X0000000e //矩陣轉(zhuǎn)置失敗 #define _ERROR_CREATE_VECTOR_FAILED 0X0000000f //創(chuàng)建向量失敗 #define _ERROR_VECTOR_DIMENSION_NOT_EQUAL 0X00000010 //向量維數(shù)不相同 #define _ERROR_VECTOR_NORM_TYPE_INVALID 0X00000011 //向量模類型無效 #define _ERROR_VECTOR_CROSS_FAILED 0X00000012 //向量叉乘失敗 #define _ERROR_INPUT_PARAMETERS_ERROR 0X00010000 //輸入?yún)?shù)錯誤 /******************************************************************************* * (4)Struct(Data Types) Define Section *******************************************************************************/ typedef unsigned int ERROR_ID; typedef int INDEX; typedef short FLAG; typedef int INTEGER; typedef double REAL; typedef char* STRING; typedef void VOID; typedef struct matrix { INTEGER rows; INTEGER columns; REAL* p; }MATRIX; typedef struct matrix_node { MATRIX* ptr; struct matrix_node* next; } MATRIX_NODE; typedef struct matrix_element_node { REAL* ptr; struct matrix_element_node* next; } MATRIX_ELEMENT_NODE; typedef struct stacks { MATRIX_NODE* matrixNode; MATRIX_ELEMENT_NODE* matrixElementNode; // ... // 添加其他對象的指針 } STACKS; /******************************************************************************* * (5)Prototype Declare Section *******************************************************************************/ /********************************************************************************************** Function: init_stack Description: 初始化棧 Input: 無 Output: 無 Input_Output: 棧指針 Return: 無 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ VOID init_stack(_IN_OUT STACKS* S); /********************************************************************************************** Function: free_stack Description: 釋放棧 Input: 棧指針 Output: 無 Input_Output: 無 Return: 無 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ VOID free_stack(_IN STACKS* S); #endif
matrix.h
/******************************************************************************* * File Name : matrix.h * Library/Module Name : MatrixComputation * Author : Marc Pony(marc_pony@163.com) * Create Date : 2021/6/28 * Abstract Description : 矩陣運算庫頭文件 *******************************************************************************/ #ifndef __MATRIX_H__ #define __MATRIX_H__ /******************************************************************************* * (1)Debug Switch Section *******************************************************************************/ /******************************************************************************* * (2)Include File Section *******************************************************************************/ #include "common.h" /******************************************************************************* * (3)Macro Define Section *******************************************************************************/ /******************************************************************************* * (4)Struct(Data Types) Define Section *******************************************************************************/ /******************************************************************************* * (5)Prototype Declare Section *******************************************************************************/ void print_matrix(MATRIX* a, STRING string); /********************************************************************************************** Function: creat_matrix Description: 創(chuàng)建矩陣 Input: 矩陣行數(shù)rows,列數(shù)columns Output: 錯誤號指針errorID,棧指針S Input_Output: 無 Return: 矩陣指針 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ MATRIX* creat_matrix(_IN INTEGER rows, _IN INTEGER columns, _OUT ERROR_ID* errorID, _OUT STACKS* S); /********************************************************************************************** Function: creat_multiple_matrices Description: 創(chuàng)建多個矩陣 Input: 矩陣行數(shù)rows,列數(shù)columns,個數(shù)count Output: 錯誤號指針errorID,棧指針S Input_Output: 無 Return: 矩陣指針 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ MATRIX* creat_multiple_matrices(_IN INTEGER rows, _IN INTEGER columns, _IN INTEGER count, _OUT ERROR_ID* errorID, _OUT STACKS* S); /********************************************************************************************** Function: creat_zero_matrix Description: 創(chuàng)建零矩陣 Input: 矩陣行數(shù)rows,列數(shù)columns Output: 錯誤號指針errorID,棧指針S Input_Output: 無 Return: 矩陣指針 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ MATRIX* creat_zero_matrix(_IN INTEGER rows, _IN INTEGER columns, _OUT ERROR_ID* errorID, _OUT STACKS* S); /********************************************************************************************** Function: creat_eye_matrix Description: 創(chuàng)建單位矩陣 Input: 矩陣行數(shù)rows,列數(shù)columns Output: 錯誤號指針errorID,棧指針S Input_Output: 無 Return: 矩陣指針 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ MATRIX* creat_eye_matrix(_IN INTEGER n, _OUT ERROR_ID* errorID, _OUT STACKS* S); /********************************************************************************************** Function: matrix_add Description: 矩陣A + 矩陣B = 矩陣C Input: 矩陣A,矩陣B Output: 矩陣C Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_add(_IN MATRIX* A, _IN MATRIX* B, _OUT MATRIX *C); /********************************************************************************************** Function: matrix_subtraction Description: 矩陣A - 矩陣B = 矩陣C Input: 矩陣A,矩陣B Output: 矩陣C Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_subtraction(_IN MATRIX* A, _IN MATRIX* B, _OUT MATRIX* C); /********************************************************************************************** Function: matrix_multiplication Description: 矩陣乘法C = A * B Input: 矩陣A,矩陣B Output: 矩陣C Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_multiplication(_IN MATRIX* A, _IN MATRIX* B, _OUT MATRIX* C); /********************************************************************************************** Function: matrix_inverse Description: 矩陣求逆 Input: 矩陣A Output: 矩陣A的逆矩陣 Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_inverse(_IN MATRIX* A, _OUT MATRIX* invA); /********************************************************************************************** Function: matrix_transpose Description: 矩陣轉(zhuǎn)置 Input: 矩陣A Output: 矩陣A的轉(zhuǎn)置 Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_transpose(_IN MATRIX* A, _OUT MATRIX* transposeA); /********************************************************************************************** Function: matrix_trace Description: 矩陣的跡 Input: 矩陣A Output: 矩陣A的跡 Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_trace(_IN MATRIX* A, _OUT REAL* trace); /********************************************************************************************** Function: lup_decomposition Description: n行n列矩陣LUP分解PA = L * U Input: n行n列矩陣A Output: n行n列下三角矩陣L,n行n列上三角矩陣U,n行n列置換矩陣P Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) 參考:https://zhuanlan.zhihu.com/p/84210687 ***********************************************************************************************/ ERROR_ID lup_decomposition(_IN MATRIX* A, _OUT MATRIX* L, _OUT MATRIX* U, _OUT MATRIX* P); /********************************************************************************************** Function: solve_matrix_equation_by_lup_decomposition Description: LUP分解解矩陣方程AX=B,其中A為n行n列矩陣,B為n行m列矩陣,X為n行m列待求矩陣(寫到矩陣B) Input: n行n列矩陣A Output: 無 Input_Output: n行m列矩陣B(即n行m列待求矩陣X) Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID solve_matrix_equation_by_lup_decomposition(_IN MATRIX* A, _IN_OUT MATRIX* B); #endif
common.c
/******************************************************************************* * File Name : common.c * Library/Module Name : MatrixComputation * Author : Marc Pony(marc_pony@163.com) * Create Date : 2021/7/16 * Abstract Description : 矩陣運算庫公用源文件 *******************************************************************************/ /******************************************************************************* * (1)Debug Switch Section *******************************************************************************/ /******************************************************************************* * (2)Include File Section *******************************************************************************/ #include "common.h" /******************************************************************************* * (3)Macro Define Section *******************************************************************************/ /******************************************************************************* * (4)Struct(Data Types) Define Section *******************************************************************************/ /******************************************************************************* * (5)Prototype Declare Section *******************************************************************************/ /******************************************************************************* * (6)Global Variable Declare Section *******************************************************************************/ /******************************************************************************* * (7)File Static Variable Define Section *******************************************************************************/ /******************************************************************************* * (8)Function Define Section *******************************************************************************/ /********************************************************************************************** Function: init_stack Description: 初始化棧 Input: 無 Output: 無 Input_Output: 棧指針 Return: 無 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ VOID init_stack(_IN_OUT STACKS* S) { if (S == NULL) { return; } memset(S, 0, sizeof(STACKS)); } /********************************************************************************************** Function: free_stack Description: 釋放棧 Input: 棧指針 Output: 無 Input_Output: 無 Return: 無 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ VOID free_stack(_IN STACKS* S) { MATRIX_NODE* matrixNode = NULL; MATRIX_ELEMENT_NODE* matrixElementNode = NULL; if (S == NULL) { return; } while (S->matrixNode != NULL) { matrixNode = S->matrixNode; S->matrixNode = matrixNode->next; free(matrixNode->ptr); matrixNode->ptr = NULL; free(matrixNode); matrixNode = NULL; } while (S->matrixElementNode != NULL) { matrixElementNode = S->matrixElementNode; S->matrixElementNode = matrixElementNode->next; free(matrixElementNode->ptr); matrixElementNode->ptr = NULL; free(matrixElementNode); matrixElementNode = NULL; } // ... // 釋放其他指針 } matrix.c /******************************************************************************* * File Name : matrix.c * Library/Module Name : MatrixComputation * Author : Marc Pony(marc_pony@163.com) * Create Date : 2021/2/24 * Abstract Description : 矩陣運算庫源文件 *******************************************************************************/ /******************************************************************************* * (1)Debug Switch Section *******************************************************************************/ /******************************************************************************* * (2)Include File Section *******************************************************************************/ #include "matrix.h" /******************************************************************************* * (3)Macro Define Section *******************************************************************************/ /******************************************************************************* * (4)Struct(Data Types) Define Section *******************************************************************************/ /******************************************************************************* * (5)Prototype Declare Section *******************************************************************************/ /******************************************************************************* * (6)Global Variable Declare Section *******************************************************************************/ /******************************************************************************* * (7)File Static Variable Define Section *******************************************************************************/ /******************************************************************************* * (8)Function Define Section *******************************************************************************/ VOID print_matrix(MATRIX* a, STRING string) { INDEX i, j; printf("matrix %s:", string); printf("\n"); for (i = 0; i < a->rows; i++) { for (j = 0; j < a->columns; j++) { printf("%f ", a->p[i * a->columns + j]); } printf("\n"); } printf("\n"); } /********************************************************************************************** Function: creat_matrix Description: 創(chuàng)建矩陣 Input: 矩陣行數(shù)rows,列數(shù)columns Output: 錯誤號指針errorID,棧指針S Input_Output: 無 Return: 矩陣指針 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ MATRIX* creat_matrix(_IN INTEGER rows, _IN INTEGER columns, _OUT ERROR_ID* errorID, _OUT STACKS* S) { MATRIX* matrix = NULL; MATRIX_NODE* matrixNode = NULL; MATRIX_ELEMENT_NODE* matrixElementNode = NULL; *errorID = _ERROR_NO_ERROR; if (rows <= 0 || columns <= 0 || errorID == NULL || S == NULL) { *errorID = _ERROR_INPUT_PARAMETERS_ERROR; return NULL; } matrix = (MATRIX*)malloc(sizeof(MATRIX)); matrixNode = (MATRIX_NODE*)malloc(sizeof(MATRIX_NODE)); matrixElementNode = (MATRIX_ELEMENT_NODE*)malloc(sizeof(MATRIX_ELEMENT_NODE)); if (matrix == NULL || matrixNode == NULL || matrixElementNode == NULL) { free(matrix); matrix = NULL; free(matrixNode); matrixNode = NULL; free(matrixElementNode); matrixElementNode = NULL; *errorID = _ERROR_FAILED_TO_ALLOCATE_HEAP_MEMORY; return NULL; } matrix->rows = rows; matrix->columns = columns; matrix->p = (REAL*)malloc(rows * columns * sizeof(REAL)); //確保matrix非空才能執(zhí)行指針操作 if (matrix->p == NULL) { free(matrix->p); matrix->p = NULL; free(matrix); matrix = NULL; free(matrixNode); matrixNode = NULL; free(matrixElementNode); matrixElementNode = NULL; *errorID = _ERROR_FAILED_TO_ALLOCATE_HEAP_MEMORY; return NULL; } matrixNode->ptr = matrix; matrixNode->next = S->matrixNode; S->matrixNode = matrixNode; matrixElementNode->ptr = matrix->p; matrixElementNode->next = S->matrixElementNode; S->matrixElementNode = matrixElementNode; return matrix; } /********************************************************************************************** Function: creat_multiple_matrices Description: 創(chuàng)建多個矩陣 Input: 矩陣行數(shù)rows,列數(shù)columns,個數(shù)count Output: 錯誤號指針errorID,棧指針S Input_Output: 無 Return: 矩陣指針 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ MATRIX* creat_multiple_matrices(_IN INTEGER rows, _IN INTEGER columns, _IN INTEGER count, _OUT ERROR_ID* errorID, _OUT STACKS* S) { INDEX i; MATRIX* matrix = NULL, *p = NULL; MATRIX_NODE* matrixNode = NULL; *errorID = _ERROR_NO_ERROR; if (rows <= 0 || columns <= 0 || count <= 0 || errorID == NULL || S == NULL) { *errorID = _ERROR_INPUT_PARAMETERS_ERROR; return NULL; } matrix = (MATRIX*)malloc(count * sizeof(MATRIX)); matrixNode = (MATRIX_NODE*)malloc(sizeof(MATRIX_NODE)); if (matrix == NULL || matrixNode == NULL) { free(matrix); matrix = NULL; free(matrixNode); matrixNode = NULL; *errorID = _ERROR_FAILED_TO_ALLOCATE_HEAP_MEMORY; return NULL; } for (i = 0; i < count; i++) { p = creat_matrix(rows, columns, errorID, S); if (p == NULL) { free(matrix); matrix = NULL; free(matrixNode); matrixNode = NULL; *errorID = _ERROR_FAILED_TO_ALLOCATE_HEAP_MEMORY; return NULL; } matrix[i] = *p; } matrixNode->ptr = matrix; matrixNode->next = S->matrixNode; S->matrixNode = matrixNode; return matrix; } /********************************************************************************************** Function: creat_zero_matrix Description: 創(chuàng)建零矩陣 Input: 矩陣行數(shù)rows,列數(shù)columns Output: 錯誤號指針errorID,棧指針S Input_Output: 無 Return: 矩陣指針 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ MATRIX* creat_zero_matrix(_IN INTEGER rows, _IN INTEGER columns, _OUT ERROR_ID* errorID, _OUT STACKS* S) { MATRIX* matrix = NULL; *errorID = _ERROR_NO_ERROR; if (rows <= 0 || columns <= 0 || errorID == NULL || S == NULL) { *errorID = _ERROR_INPUT_PARAMETERS_ERROR; return NULL; } matrix = creat_matrix(rows, columns, errorID, S); if (*errorID == _ERROR_NO_ERROR) { memset(matrix->p, 0, rows * columns * sizeof(REAL)); } return matrix; } /********************************************************************************************** Function: creat_eye_matrix Description: 創(chuàng)建單位矩陣 Input: 矩陣行數(shù)rows,列數(shù)columns Output: 錯誤號指針errorID,棧指針S Input_Output: 無 Return: 矩陣指針 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ MATRIX* creat_eye_matrix(_IN INTEGER n, _OUT ERROR_ID* errorID, _OUT STACKS* S) { INDEX i; MATRIX* matrix = NULL; *errorID = _ERROR_NO_ERROR; if (n <= 0 || errorID == NULL || S == NULL) { *errorID = _ERROR_INPUT_PARAMETERS_ERROR; return NULL; } matrix = creat_matrix(n, n, errorID, S); if (*errorID == _ERROR_NO_ERROR) { memset(matrix->p, 0, n * n * sizeof(REAL)); for (i = 0; i < n; i++) { matrix->p[i * n + i] = 1.0; } } return matrix; } /********************************************************************************************** Function: matrix_add Description: 矩陣A + 矩陣B = 矩陣C Input: 矩陣A,矩陣B Output: 矩陣C Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_add(_IN MATRIX* A, _IN MATRIX* B, _OUT MATRIX* C) { INDEX i, j; INTEGER rows, columns; ERROR_ID errorID = _ERROR_NO_ERROR; if (A == NULL || B == NULL || C == NULL) { errorID = _ERROR_INPUT_PARAMETERS_ERROR; return errorID; } if (A->rows != B->rows || A->rows != C->rows || B->rows != C->rows || A->columns != B->columns || A->columns != C->columns || B->columns != C->columns) { errorID = _ERROR_MATRIX_ROWS_OR_COLUMNS_NOT_EQUAL; return errorID; } rows = A->rows; columns = A->columns; for (i = 0; i < rows; i++) { for (j = 0; j < columns; j++) { C->p[i * columns + j] = A->p[i * columns + j] + B->p[i * columns + j]; } } return errorID; } /********************************************************************************************** Function: matrix_subtraction Description: 矩陣A - 矩陣B = 矩陣C Input: 矩陣A,矩陣B Output: 矩陣C Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_subtraction(_IN MATRIX* A, _IN MATRIX* B, _OUT MATRIX* C) { INDEX i, j; INTEGER rows, columns; ERROR_ID errorID = _ERROR_NO_ERROR; if (A == NULL || B == NULL || C == NULL) { errorID = _ERROR_INPUT_PARAMETERS_ERROR; return errorID; } if (A->rows != B->rows || A->rows != C->rows || B->rows != C->rows || A->columns != B->columns || A->columns != C->columns || B->columns != C->columns) { errorID = _ERROR_MATRIX_ROWS_OR_COLUMNS_NOT_EQUAL; return errorID; } rows = A->rows; columns = A->columns; for (i = 0; i < rows; i++) { for (j = 0; j < columns; j++) { C->p[i * columns + j] = A->p[i * columns + j] - B->p[i * columns + j]; } } return errorID; } /********************************************************************************************** Function: matrix_multiplication Description: 矩陣乘法C = A * B Input: 矩陣A,矩陣B Output: 矩陣C Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_multiplication(_IN MATRIX* A, _IN MATRIX* B, _OUT MATRIX* C) { INDEX i, j, k; REAL sum; ERROR_ID errorID = _ERROR_NO_ERROR; if (A == NULL || B == NULL || C == NULL) { errorID = _ERROR_INPUT_PARAMETERS_ERROR; return errorID; } if (A->columns != B->rows || A->rows != C->rows || B->columns != C->columns) { errorID = _ERROR_MATRIX_MULTIPLICATION; return errorID; } for (i = 0; i < A->rows; i++) { for (j = 0; j < B->columns; j++) { sum = 0.0; for (k = 0; k < A->columns; k++) { sum += A->p[i * A->columns + k] * B->p[k * B->columns + j]; } C->p[i * B->columns + j] = sum; } } return errorID; } /********************************************************************************************** Function: matrix_inverse Description: 矩陣求逆 Input: 矩陣A Output: 矩陣A的逆矩陣 Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_inverse(_IN MATRIX* A, _OUT MATRIX* invA) { INDEX i; INTEGER n; MATRIX* ATemp = NULL; ERROR_ID errorID = _ERROR_NO_ERROR; STACKS S; if (A == NULL || invA == NULL) { errorID = _ERROR_INPUT_PARAMETERS_ERROR; return errorID; } if (A->rows != A->columns) { errorID = _ERROR_MATRIX_MUST_BE_SQUARE; return errorID; } init_stack(&S); n = A->rows; ATemp = creat_matrix(n, n, &errorID, &S); if (errorID != _ERROR_NO_ERROR) goto EXIT; memcpy(ATemp->p, A->p, n * n * sizeof(REAL)); memset(invA->p, 0, n * n * sizeof(REAL)); for (i = 0; i < n; i++) { invA->p[i * n + i] = 1.0; } errorID = solve_matrix_equation_by_lup_decomposition(ATemp, invA); EXIT: free_stack(&S); return errorID; } /********************************************************************************************** Function: matrix_transpose Description: 矩陣轉(zhuǎn)置 Input: 矩陣A Output: 矩陣A的轉(zhuǎn)置 Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_transpose(_IN MATRIX* A, _OUT MATRIX* transposeA) { INDEX i, j; ERROR_ID errorID = _ERROR_NO_ERROR; if (A == NULL || transposeA == NULL) { errorID = _ERROR_INPUT_PARAMETERS_ERROR; return errorID; } if (A->rows != transposeA->columns || A->columns != transposeA->rows) { errorID = _ERROR_MATRIX_TRANSPOSE_FAILED; return errorID; } for (i = 0; i < A->rows; i++) { for (j = 0; j < A->columns; j++) { transposeA->p[j * A->rows + i] = A->p[i * A->columns + j]; } } return errorID; } /********************************************************************************************** Function: matrix_trace Description: 矩陣的跡 Input: 矩陣A Output: 矩陣A的跡 Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID matrix_trace(_IN MATRIX* A, _OUT REAL *trace) { INDEX i; ERROR_ID errorID = _ERROR_NO_ERROR; if (A == NULL || trace == NULL) { errorID = _ERROR_INPUT_PARAMETERS_ERROR; return errorID; } if (A->rows != A->columns) { errorID = _ERROR_MATRIX_MUST_BE_SQUARE; return errorID; } *trace = 0.0; for (i = 0; i < A->rows; i++) { *trace += A->p[i * A->columns + i]; } return errorID; } /********************************************************************************************** Function: lup_decomposition Description: n行n列矩陣LUP分解PA = L * U Input: n行n列矩陣A Output: n行n列下三角矩陣L,n行n列上三角矩陣U,n行n列置換矩陣P Input_Output: 無 Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) 參考:https://zhuanlan.zhihu.com/p/84210687 ***********************************************************************************************/ ERROR_ID lup_decomposition(_IN MATRIX* A, _OUT MATRIX* L, _OUT MATRIX* U, _OUT MATRIX* P) { INDEX i, j, k, index, s, t; INTEGER n; REAL maxValue, temp; ERROR_ID errorID = _ERROR_NO_ERROR; if (A == NULL || L == NULL || U == NULL || P == NULL) { errorID = _ERROR_INPUT_PARAMETERS_ERROR; return errorID; } if (A->rows != A->columns) { errorID = _ERROR_MATRIX_MUST_BE_SQUARE; return errorID; } n = A->rows; memcpy(U->p, A->p, n * n * sizeof(REAL)); memset(L->p, 0, n * n * sizeof(REAL)); memset(P->p, 0, n * n * sizeof(REAL)); for (i = 0; i < n; i++) { L->p[i * n + i] = 1.0; P->p[i * n + i] = 1.0; } for (j = 0; j < n - 1; j++) { //Select i(>= j) that maximizes | U(i, j) | index = -1; maxValue = 0.0; for (i = j; i < n; i++) { temp = fabs(U->p[i * n + j]); if (temp > maxValue) { maxValue = temp; index = i; } } if (index == -1) { continue; } //Interchange rows of U : U(j, j : n) < ->U(i, j : n) for (k = j; k < n; k++) { s = j * n + k; t = index * n + k; temp = U->p[s]; U->p[s] = U->p[t]; U->p[t] = temp; } //Interchange rows of L : L(j, 1 : j - 1) < ->L(i, 1 : j - 1) for (k = 0; k < j; k++) { s = j * n + k; t = index * n + k; temp = L->p[s]; L->p[s] = L->p[t]; L->p[t] = temp; } //Interchange rows of P : P(j, 1 : n) < ->P(i, 1 : n) for (k = 0; k < n; k++) { s = j * n + k; t = index * n + k; temp = P->p[s]; P->p[s] = P->p[t]; P->p[t] = temp; } for (i = j + 1; i < n; i++) { s = i * n + j; L->p[s] = U->p[s] / U->p[j * n + j]; for (k = j; k < n; k++) { U->p[i * n + k] -= L->p[s] * U->p[j * n + k]; } } } return errorID; } /********************************************************************************************** Function: solve_matrix_equation_by_lup_decomposition Description: LUP分解解矩陣方程AX=B,其中A為n行n列矩陣,B為n行m列矩陣,X為n行m列待求矩陣(寫到矩陣B) Input: n行n列矩陣A Output: 無 Input_Output: n行m列矩陣B(即n行m列待求矩陣X) Return: 錯誤號 Author: Marc Pony(marc_pony@163.com) ***********************************************************************************************/ ERROR_ID solve_matrix_equation_by_lup_decomposition(_IN MATRIX* A, _IN_OUT MATRIX* B) { INDEX i, j, k, index, s, t; INTEGER n, m; REAL sum, maxValue, temp; MATRIX* L = NULL, * U = NULL, * y = NULL; ERROR_ID errorID = _ERROR_NO_ERROR; STACKS S; if (A == NULL || B == NULL) { errorID = _ERROR_INPUT_PARAMETERS_ERROR; return errorID; } if (A->rows != A->columns) { errorID = _ERROR_MATRIX_MUST_BE_SQUARE; return errorID; } init_stack(&S); n = A->rows; m = B->columns; L = creat_matrix(n, n, &errorID, &S); if (errorID != _ERROR_NO_ERROR) goto EXIT; U = creat_matrix(n, n, &errorID, &S); if (errorID != _ERROR_NO_ERROR) goto EXIT; y = creat_matrix(n, m, &errorID, &S); if (errorID != _ERROR_NO_ERROR) goto EXIT; memcpy(U->p, A->p, n * n * sizeof(REAL)); memset(L->p, 0, n * n * sizeof(REAL)); for (i = 0; i < n; i++) { L->p[i * n + i] = 1.0; } for (j = 0; j < n - 1; j++) { //Select i(>= j) that maximizes | U(i, j) | index = -1; maxValue = 0.0; for (i = j; i < n; i++) { temp = fabs(U->p[i * n + j]); if (temp > maxValue) { maxValue = temp; index = i; } } if (index == -1) { continue; } //Interchange rows of U : U(j, j : n) < ->U(i, j : n) for (k = j; k < n; k++) { s = j * n + k; t = index * n + k; temp = U->p[s]; U->p[s] = U->p[t]; U->p[t] = temp; } //Interchange rows of L : L(j, 1 : j - 1) < ->L(i, 1 : j - 1) for (k = 0; k < j; k++) { s = j * n + k; t = index * n + k; temp = L->p[s]; L->p[s] = L->p[t]; L->p[t] = temp; } //Interchange rows of P : P(j, 1 : n) < ->P(i, 1 : n), C = P * B,等價于對B交換行 for (k = 0; k < m; k++) { s = j * m + k; t = index * m + k; temp = B->p[s]; B->p[s] = B->p[t]; B->p[t] = temp; } for (i = j + 1; i < n; i++) { s = i * n + j; L->p[s] = U->p[s] / U->p[j * n + j]; for (k = j; k < n; k++) { U->p[i * n + k] -= L->p[s] * U->p[j * n + k]; } } } for (i = 0; i < n; i++) { if (fabs(U->p[i * n + i]) < 1.0e-20) { errorID = _ERROR_MATRIX_EQUATION_HAS_NO_SOLUTIONS; goto EXIT; } } //L * y = C for (j = 0; j < m; j++) { for (i = 0; i < n; i++) { sum = 0.0; for (k = 0; k < i; k++) { sum = sum + L->p[i * n + k] * y->p[k * m + j]; } y->p[i * m + j] = B->p[i * m + j] - sum; } } //U * x = y for (j = 0; j < m; j++) { for (i = n - 1; i >= 0; i--) { sum = 0.0; for (k = i + 1; k < n; k++) { sum += U->p[i * n + k] * B->p[k * m + j]; } B->p[i * m + j] = (y->p[i * m + j] - sum) / U->p[i * n + i]; } } EXIT: free_stack(&S); return errorID; }
test_matrix.c
#include "matrix.h" void main() { REAL a[3 * 3] = { 1,2,3,6,5,5,8,7,2 }; REAL b[3 * 3] = {1,2,3,6,5,4,3,2,1}; MATRIX *A = NULL, * B = NULL, * C = NULL, * D = NULL, * E = NULL, * Z = NULL, * invA = NULL, *m = NULL; ERROR_ID errorID = _ERROR_NO_ERROR; REAL trace; STACKS S; init_stack(&S); Z = creat_zero_matrix(3, 3, &errorID, &S); print_matrix(Z, "Z"); E = creat_eye_matrix(3, &errorID, &S); print_matrix(E, "E"); A = creat_matrix(3, 3, &errorID, &S); A->p = a; print_matrix(A, "A"); B = creat_matrix(3, 3, &errorID, &S); B->p = b; print_matrix(B, "B"); C = creat_matrix(3, 3, &errorID, &S); D = creat_matrix(3, 3, &errorID, &S); invA = creat_matrix(3, 3, &errorID, &S); errorID = matrix_add(A, B, C); errorID = matrix_subtraction(A, B, C); errorID = matrix_multiplication(A, B, C); errorID = matrix_transpose(A, D); print_matrix(D, "D"); errorID = matrix_trace(A, &trace); errorID = matrix_inverse(A, invA); print_matrix(invA, "invA"); m = creat_multiple_matrices(3, 3, 2, &errorID, &S); m[0].p = a; m[1].p = b; free_stack(&S); }
參考資料
The NURBS Book(Second Edition). Les Piegl,Wayne Tiller
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