int readFile(double values[][MAX_COLUMNS], int maxRows, string inputFileName){
    ifstream inFile;
    inFile.open(inputFileName);

    int rows;

    if (!inFile)
        return -1;
    else{
        for (rows = 0; rows < maxRows && !inFile.eof(); rows++){
            for (int cols = 0; cols < MAX_COLUMNS; cols++){
                inFile >> values[rows][cols];
                if (inFile.fail() && rows == 0)
                    return 0;
            }
        }
    }
    inFile.close();
    return rows;
}