Hi，大家好，我是编程小6，很荣幸遇见你，我把这些年在开发过程中遇到的问题或想法写出来，今天说一说
C语言矩阵运算_c++实现矩阵运算,希望能够帮助你!!!。

这是一个用C语言编写的矩阵运算头文件，话不多说，上代码

matrix.h

/** * File name: matrix.h * Author: Tiancai Xu * Version: 1.0 * Data: 2021-10-29 * Copyright: 2021.10, Tiancai Xu * This file defines the matrix and its basic operations * This file is for study or reference only */ #ifndef _STDARG_H #include <stdarg.h> #endif // _STDARG_H #ifndef _STDIO_H #include <stdio.h> #endif // _STDIO_H #ifndef _STDLIB_H #include <stdlib.h> #endif // _STDLIB_H #ifndef _TIME_H #include <time.h> #endif // _TIME_H #ifndef _MATRIX_H #define _MATRIX_H #define size_m unsigned int /**< Matrix variable */ typedef struct { double** M; /**< Data of Matrix */ size_m row; /**< The number of row */ size_m col; /**< The number of column */ } Matrix; /**< Tips: This format is recommended for declarations: Matrix M = {NULL, 0, 0}; */ Matrix from(double* arr, size_m row, size_m col); Matrix zeros(size_m row, size_m col); Matrix ones(size_m row, size_m col); Matrix diag(int order, ...); Matrix diag_M(Matrix A); Matrix iden(int order); Matrix randM(size_m row, size_m col); Matrix add(Matrix A, Matrix B); Matrix sub(Matrix A, Matrix B); Matrix mult_MM(Matrix A, Matrix B); Matrix mult_kM(double k, Matrix B); Matrix T(Matrix A); Matrix inv(Matrix A); Matrix cof(Matrix A, int r, int c); double mode(Matrix A); void scanM(Matrix* A); void printM(Matrix A); void clearM(Matrix* A); #endif // _MATRIX_H 

matrix.c

/** * File name: matrix.c * Author: Tiancai Xu * Version: 1.0 * Data: 2021-10-29 * Copyright: 2021.10, Tiancai Xu * This file includes the implementation of the functions declarated in matrix.h * This file is for study or reference only */ #include "matrix.h" /** \brief Create a block of 2-D array memory * * \param row The number of row * \param col The number of column * \return M 2-D array pointer * */ static double** getM(size_m row, size_m col) { int i; double** M; M = (double**)malloc(sizeof(double*) * row); for (i = 0; i < row; i++) *(M + i) = (double*)malloc(sizeof(double) * col); return M; } /** \brief Transform a 2-D array to Matrix * * \param arr The first adress of the a-D array * \param row The number of row * \param col The number of column * \return M Matrix * * For a 2-D array arr[r][c], use from((double*)arr,r,c) to avoid the gcc compiler warning */ Matrix from(double* arr, size_m row, size_m col) { int i, j; Matrix M; M.row = row; M.col = col; M.M = getM(row, col); for (i = 0; i < row; i++) for (j = 0; j < col; j++) M.M[i][j] = *(arr + i * col + j); return M; } /** \brief Create a zeros Matrix * * \param row The number of row * \param col The number of column * \return M Matrix * */ Matrix zeros(size_m row, size_m col) { int i, j; Matrix M; M.row = row; M.col = col; M.M = getM(row, col); for (i = 0; i < row; i++) for (j = 0; j < col; j++) M.M[i][j] = 0; return M; } /** \brief Create a ones Matrix * * \param row The number of row * \param col The number of column * \return M Matrix * */ Matrix ones(size_m row, size_m col) { int i, j; Matrix M; M.row = row; M.col = col; M.M = getM(row, col); for (i = 0; i < row; i++) for (j = 0; j < col; j++) M.M[i][j] = 1; return M; } /** \brief Create a diagonal Matrix * * \param order The order of the Matrix * \return M Matrix * */ Matrix diag(int order, ...) { int i; va_list valist; Matrix M; M = zeros(order, order); va_start(valist, order); for (i = 0; i < order; i++) M.M[i][i] = va_arg(valist, double); return M; } /** \brief Create a diagonal Matrix * * \param A It's a row or column vector * \return M Matrix * */ Matrix diag_M(Matrix A) { int i, order; Matrix M; order = A.row * A.col; M = zeros(order, order); if (A.row == 1) for (i = 0; i < order; i++) M.M[i][i] = A.M[0][i]; else if (A.col == 1) for (i = 0; i < order; i++) M.M[i][i] = A.M[i][0]; else { fprintf(stderr, "Error: Arguments must be a row or column vector.\n"); exit(-1); } return M; } /** \brief Create a identity Matrix * * \param order The order of the Matrix * \return M Matrix * */ Matrix iden(int order) { int i; Matrix M; M = zeros(order, order); for (i = 0; i < order; i++) M.M[i][i] = 1; return M; } /** \brief Create a random Matrix between 0 and 1.0 * * \param row The number of row * \param col The number of column * \return M Matrix * */ Matrix randM(size_m row, size_m col) { time_t t; int i, j; Matrix M = zeros(row, col); srand((unsigned) time(&t)); for (i = 0; i < row; i++) for (j = 0; j < col; j++) M.M[i][j] = ((double) rand()) / ((double)RAND_MAX); return M; } /** \brief Matrix addition * * \param A Matrix * \param B Matrix * \return M Matrix, M = A + B * */ Matrix add(Matrix A, Matrix B) { if (!(A.row == B.row && A.col == B.col)) { fprintf(stderr, "Error: The two matrices must have the same size.\n"); exit(-1); } int i, j; Matrix M; M.row = A.row; M.col = A.col; M.M = getM(M.row, M.col); for (i = 0; i < M.row; i++) for (j = 0; j < M.col; j++) M.M[i][j] = A.M[i][j] + B.M[i][j]; return M; } /** \brief Matrix subtraction * * \param A Matrix * \param B Matrix * \return M Matrix, M = A - B * */ Matrix sub(Matrix A, Matrix B) { if (!(A.row == B.row && A.col == B.col)) { fprintf(stderr, "Error: The two matrices must have the same size.\n"); exit(-1); } int i, j; Matrix M; M.row = A.row; M.col = A.col; M.M = getM(M.row, M.col); for (i = 0; i < M.row; i++) for (j = 0; j < M.col; j++) M.M[i][j] = A.M[i][j] - B.M[i][j]; return M; } /** \brief Matrix multiplication * * \param A Matrix * \param B Matrix * \return M Matrix, M = A * B * */ Matrix mult_MM(Matrix A, Matrix B) { if (A.col != B.row) { fprintf(stderr, "Error: The number of columns in matrix A must be equal to the number of rows in matrix B.\n"); exit(-1); } int i, j, k; Matrix M; M.row = A.row; M.col = B.col; M.M = getM(M.row, M.col); for (i = 0; i < M.row; i++) for (j = 0; j < M.col; j++) { M.M[i][j] = 0; for (k = 0; k < A.col; k++) M.M[i][j] += A.M[i][k] * B.M[k][j]; } return M; } /** \brief Matrix multiplication * * \param k Real number * \param A Matrix * \return M Matrix, M = k * A * */ Matrix mult_kM(double k, Matrix B) { int i, j; Matrix M; M.row = B.row; M.col = B.col; M.M = getM(M.row, M.col); for (i = 0; i < M.row; i++) for (j = 0; j < M.col; j++) M.M[i][j] = k * B.M[i][j]; return M; } /** \brief Matrix transpose * * \param A Matrix * \return M Matrix, M = A^T * */ Matrix T(Matrix A) { int i, j; Matrix M; M.row = A.col; M.col = A.row; M.M = getM(M.row, M.col); for (i = 0; i < M.row; i++) for (j = 0; j < M.col; j++) M.M[i][j] = A.M[j][i]; return M; } /** \brief Matrix inversion * * \param A Matrix * \return M Inverse Matrix, M = A^-1 * */ Matrix inv(Matrix A) { if (A.row != A.col) { fprintf(stderr, "Error: The matrix must be square.\n"); exit(-1); } int m = mode(A); if (m == 0) { fprintf(stderr, "Error: The inverse of the target matrix does not exist.\n"); exit(-1); } int i, j, s; Matrix M, temp; M.row = A.row; M.col = A.col; M.M = getM(M.row, M.col); for (i = 0; i < M.row; i++) for (j = 0; j < M.col; j++) { temp = cof(A, i, j); s = (i + j) % 2 == 0 ? 1 : -1; M.M[j][i] = s * mode(temp) / m; clearM(&temp); } return M; } /** \brief Complementary minor, cofactor * * \param A Matrix * \param r The index of row * \param c The index of column * \return M The cofactor Matrix M[r][c] * */ Matrix cof(Matrix A, int r, int c) { if (A.row != A.col) { fprintf(stderr, "Error: The matrix must be square.\n"); exit(-1); } if (r < 0 || r > A.row) { fprintf(stderr, "Error: Out of matrix index range.(r)\n"); exit(-1); } if (c < 0 || c > A.col) { fprintf(stderr, "Error: Out of matrix index range.(c)\n"); exit(-1); } int i, j, m, n; Matrix M; M.row = A.row - 1; M.col = A.col - 1; M.M = getM(M.row, M.col); for (i = 0, m = 0; i < A.row; i++) { if (i == r) continue; for (j = 0, n = 0; j < A.col; j++) { if (j == c) continue; M.M[m][n] = A.M[i][j]; n++; } m++; } return M; } /** \brief Get the mode of Matrix * * \param A Matrix * \return result The mode, result = |A| * */ double mode(Matrix A) { if (A.row != A.col) { fprintf(stderr, "Error: The matrix must be square.\n"); exit(-1); } if (A.row == 1) return A.M[0][0]; double result; int i, s; Matrix M; for (result = 0, i = 0; i < A.row; i++) { s = i % 2 == 0 ? 1 : -1; M = cof(A, i, 0); result += A.M[i][0] * s * mode(M); clearM(&M); } return result; } /** \brief Input a Matrix * * \param A Matrix pointer * \return void * */ void scanM(Matrix* A) { int i, j; if (A->M == NULL) { printf("Enter the number of row&column, e.g. 5,5: "); scanf("%u,%u", &A->row, &A->col); } for (i = 0; i < A->row; i++) for (j = 0; j < A->col; j++) { printf("Enter M(%d,%d): ", i, j); scanf("%lf", &A->M[i][j]); } } /** \brief Print a Matrix * * \param A Matrix * \return void * */ void printM(Matrix A) { int i, j; for (i = 0; i < A.row; i++) { for (j = 0; j < A.col; j++) printf("%-10.4g ", A.M[i][j]); printf("\n"); } } /** \brief Clear a Matrix * * \param A Matrix pointer * \return void * * To release occupied memory */ void clearM(Matrix* A) { int i; if (A->M != NULL) { for (i = 0; i < A->row; i++) free(A->M[i]); free(A->M); } A->M = NULL; A->row = 0; A->col = 0; } 

测试用test.c

/**< IDE: Code::Blocks 20.03 64bit */ #include <stdio.h> #include "matrix.h" int main() { Matrix M = {NULL, 0, 0}; Matrix M1 = {NULL, 0, 0}; Matrix M2 = {NULL, 0, 0}; printf("/*****************************/\n"); printf("\nM = zeros(2, 3)\n"); M = zeros(2, 3); printM(M); clearM(&M); printf("\n/*****************************/\n"); printf("\nM = ones(3, 2)\n"); M = ones(3, 2); printM(M); clearM(&M); printf("\n/*****************************/\n"); printf("\nM = iden(3)\n"); M = iden(3); printM(M); clearM(&M); printf("\n/*****************************/\n"); printf("\nM = diag(3, 1.0, 2.0, 3.1)\n"); M = diag(3, 1.0, 2.0, 3.1); printM(M); clearM(&M); printf("\n/*****************************/\n"); printf("\nM = randM(2, 2)\n"); M = randM(2, 2); printM(M); clearM(&M); printf("\n/*****************************/\n"); printf("\nM = from((double*)arr, 2, 3)\n"); double arr[3][3] = { 
  {1.0, 2.0, 3.0}, {2.0, 2.0, 1.0}, {3.0, 4.0, 3.0}}; M = from((double*)arr, 3, 3); printM(M); M1 = T(M); printf("\nM1 = T(M)\n"); printM(M1); printf("\nM2 = mult_MM(M1, M)\n"); M2 = mult_MM(M1, M); printM(M2); clearM(&M1); clearM(&M2); printf("\nM1 = inv(M)\n"); M1 = inv(M); printM(M1); printf("\nM1 = mult_MM(M, M1)\n"); M2 = mult_MM(M, M1); printM(M2); clearM(&M); clearM(&M1); clearM(&M2); printf("\n/*****************************/\n"); return 0; } 

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