Convert C++ code in Matlab code?

// C++ program to check whether given matrix 
// is a Toeplitz matrix or not 
#include <iostream> 
using namespace std; 
#define N 5 
#define M 4 
  
// Function to check if all elements present in 
// descending diagonal starting from position 
// (i, j) in the matrix are all same or not 
bool checkDiagonal(int mat[N][M], int i, int j) 
{ 
    int res = mat[i][j]; 
    while (++i < N && ++j < M) 
    { 
        // mismatch found 
        if (mat[i][j] != res) 
            return false; 
    } 
  
    // we only reach here when all elements 
    // in given diagonal are same 
    return true; 
} 
  
// Function to check whether given matrix is a 
// Toeplitz matrix or not 
bool isToepliz(int mat[N][M]) 
{ 
    // do for each element in first row 
    for (int i = 0; i < M; i++) 
    { 
        // check descending diagonal starting from 
        // position (0, j) in the matrix 
        if (!checkDiagonal(mat, 0, i)) 
            return false; 
    } 
  
    // do for each element in first column 
    for (int i = 1; i < N; i++) 
    { 
        // check descending diagonal starting from 
        // position (i, 0) in the matrix 
        if (!checkDiagonal(mat, i, 0)) 
            return false; 
    } 
  
    // we only reach here when each descending 
    // diagonal from left to right is same 
    return true; 
} 
  
// Driver code 
int main() 
{ 
    int mat[N][M] = 
    { 
        { 6, 7, 8, 9 }, 
        { 4, 6, 7, 8 }, 
        { 1, 4, 6, 7 }, 
        { 0, 1, 4, 6 }, 
        { 2, 0, 1, 4 } 
    }; 
  
    if (isToepliz(mat)) 
        cout << "Matrix is a Toepliz "; 
    else
        cout << "Matrix is not a Toepliz "; 
  
    return 0; 
} 

[Geoff Hayes]

Karlyann - yes, the above code could be converted to MATLAB. Are you asking someone to do that for you? Have you checked the MATLAB File Exchange to see if there is something similar?

[Karlyann Laboy Rivera]

Yes. I am asking if someone could convert this code to Matlab.

Answer 1

[Guillaume]

The code you show is hardcoded to check only matrices of size 5x4 and hardcoded to only check one matrix. Hardly useful.

In any case, there are much better ways to do this in matlab. The code below is not at all a translation of the C++ code.

function tf = istoeplitz(M)
    %returns true if M is a toeplitz matrix. False otherwise
    diags = toeplitz(size(M, 1):-1:1, size(M, 1):size(M, 1)+size(M, 2)-1);  %build indices of diagonals
    tf = all(accummaray(diags(:), M(:), [], @(dia) all(dia == dia(1)))); %check that all elements on the same diagonals are equal
end