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PODeleting a doublepointer (matrix)
 

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    <p>I am solving a quantum-mech problem which requires me to find some eigenvalues by manipulating some matrices. The specifics of this problem is not relevant, I just need help with the c++ problem, I am new to this language and after a couple of hours I figured any more attempts at solving it myself would be futile and so I turn to you for help.</p> <p>I have this problem where glibc detects an error at the end of my program and I cannot deallocate properly, it is far too big to copypaste here so I will just replicate the part that actually gives the error.</p> <pre><code>void hamiltonian(int, double **&amp;); int i,j; int main() { int N = 1000; double **A; hamiltonian(N, A); //Physics here . . . . . //Delete for(i=0; i&lt;N; i++){delete []A[i];} delete []A; return 0; } void hamiltonian(int N, double **&amp;A) { A = new double *[N]; for(i=0; i&lt;N; i++) { A[i] = new double[N]; for(j=0; j&lt;N; j++) { if(i==j)A[i][j] = 2; if(i==j+1 || i==j-1){A[i][j] = 1;} } } } </code></pre> <p>According to my professor I have to deallocate in the same function as I allocate but I didn't even think about deallocation after being nearly done with my project and so I have to rewrite a lot of code, the problem is that I cannot deallocate A inside the hamiltonian function as I need it in other functions (inside //Physics).</p> <p>Surely there must be a way around this? Might sound a bit ignorant of me but this sounds like a less efficient design if I have to deallocate in the same function as I allocate.</p>
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    1. COEdited to add delete[A] and A[i] = new double[N];
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    2. COImplementing own matrix functionality is probably OK for studying C++, but if your main goal is quantum-mech problem, isn't it better to find an existing library able to operate on matrices and work with eigenvalues?
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    3. CO@maxim1000 Yes but it is not as much fun :p
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