c++ error: redefinition of matrix class
<p>I have been struggling to get this code to compile.
I am trying to implement a simple Matrix class for use in another calculation.</p>

<p>As of now I am stuck on the following two errors:
From the compiler:</p>

<pre><code>g++ -g -Wall -c main.cpp
In file included from main.cpp:19:0:
    Matrix.hh:2:7: error: redefinition of ‘class Matrix’
    Matrix.hh:2:14: error: previous definition of ‘class Matrix’
</code></pre>

<p>I don't see any obvious redefinitions. Please help</p>

<p>Thanks</p>

<p>Here are the supporting files:</p>

<p>Matrix.hh:</p>

<pre><code>// Matrix class of variable size
class Matrix {

private:
    int n_rows;
    int n_cols;
    double *array;

public:
    // Constructors
    Matrix(); // default constructor
    Matrix(int rows, int cols); // two-argument constructor
//  Matrix(const Matrix &amp;arr); // copy constructor


    // Destructor
    ~Matrix();

    // Mutators
//  void add(Matrix m2);
//  void subtract(Matrix m2);
    void setelem(int r, int c, double val);

    // Accessors
    int getrows();
    int getcols();
    double getelem(int r, int c);
    bool equals(Matrix m2);
    char display();
    int WriteToArray(double *CopyOfArray);

};
</code></pre>

<p>Matrix.cc:</p>

<pre><code>#include "Matrix.hh"
#include &lt;cassert&gt;
#include &lt;math.h&gt;
#include &lt;string.h&gt;
#include &lt;stdio.h&gt;

// CONSTRUCTORS
// default constructor
Matrix::Matrix() {
    n_rows = 0;
    n_cols = 0;
    array = NULL;
}

// two-argument constructor
Matrix::Matrix(int rows, int cols) {
    n_rows = rows;
    n_cols = cols;
    array = new double[rows * cols];

    for (int i = 0; i &lt; n_rows; i++) {
        for (int j = 0; j &lt; n_cols; j++) {
            array[i * n_cols + j] = 0;
        }
    }
}

/* copy constructor*/
//Matrix::Matrix(const Matrix &amp;arr)  {
//  n_rows = arr.n_rows; // find proper size
//  n_cols = arr.n_cols; // find proper size
//  array = new double[n_rows * n_cols]; // allocate a deep-copy
//  for (int i = 0; i &lt; n_rows; i++) {
//      for (int j = 0; j &lt; n_cols; j++) {
//          array[i * n_cols + j] = arr.array[i * n_cols + j];
//      }
//  }
//  arr=&amp;array;
//}


// DESTRUCTOR
Matrix::~Matrix() {
    assert(array[1]!=0);
    int ii=0;
    printf("array values in ~\n");
    for(ii=0;ii&lt;n_rows;ii++){
        printf("%e\n",array[ii]);
    }
    delete[] array; // free up memory
}

// MUTATORS
// adds a second matrix to this matrix object
void Matrix::add(Matrix m2) {
    assert (m2.n_rows == n_rows); // assert dimensions match
    assert (m2.n_cols == n_cols); // assert dimensions match
    for (int i = 0; i &lt; n_rows; i++) {
        for (int j = 0; j &lt; n_cols; j++) {
            array[i * n_cols + j] = array[i * n_cols + j] + m2.array[i *n_cols + j];
        }
    }
}

// subtracts a second matrix to this matrix object
void Matrix::subtract(Matrix m2) {
assert (m2.n_rows == n_rows); // assert dimensions match
assert (m2.n_cols == n_cols); // assert dimensions match
for (int i = 0; i &lt; n_rows; i++) {
    for (int j = 0; j &lt; n_cols; j++) {
        array[i * n_cols + j] = array[i * n_cols + j] - m2.array[i *n_cols + j];
        }
    }
}

// change an element in the matrix
void Matrix::setelem(int r, int c, double val) {

    array[r * n_cols + c] = val;
}

// ACCESSORS
// get number of rows
int Matrix::getrows() {
    return n_rows;
}

// get number of columns
int Matrix::getcols() {
    return n_cols;
}

// get value of element at specified row, col
double Matrix::getelem(int r, int c) {
    printf("getelem value: %e\n", array[r*n_cols+c]);
    return array[r * n_cols + c];
}

// test if two matrices are equal
bool Matrix::equals(Matrix m2) {
    // if dimensions not equal, matrices not equal
    if (m2.n_rows != n_rows || m2.n_cols != n_cols) { 
        return false;
    }

    // test equality element by element
    for (int i = 0; i &lt; n_rows; i++) {
        for (int j = 0; j &lt; n_cols; j++) {
            if (array[i * n_cols + j] != m2.array[i * n_cols + j]) {
                return false; // if one val not equal, matrices not equal
            }
        }
    }

    return true; // has checked all vals, matrices match
}

char Matrix::display() {
    // Print out the contents of this matrix m2:
    char string[100], temp[1];
    int n;
    for(int r = 0; r &lt; n_rows; r++) {
      for(int c = 0; c &lt; n_cols; c++) {
        printf("Element (%d, %d) =  %e, \n", r,c,array[r * n_cols + c]);

      }
    }
    printf("\n");
    return *string;
}

int Matrix::WriteToArray(double *CopyOfArray){
    int i=0;
    while(i&lt;n_rows){
        *(CopyOfArray+i)=array[i*n_cols];
        i++;
    }
    return *CopyOfArray;
}
</code></pre>
