Hi,
I'm taking Computer Science for the first time and I'm trying to code a program that accepts input from a file for a square matrix and finds the determinate. I ran into some errors while working on the "Get Input Function" part of the program. Specifically the ones in my build log here:
1>------ Build started: Project: Matrix Evaluator, Configuration: Debug Win32 ------
1>Compiling...
1>matrix evaluator.cpp
1>.\matrix evaluator.cpp(279) : error C2601: 'getInput' : local function definitions are illegal
1> .\matrix evaluator.cpp(197): this line contains a '{' which has not yet been matched
1>.\matrix evaluator.cpp(432) : fatal error C1075: end of file found before the left brace '{' at '.\matrix evaluator.cpp(289)' was matched
1>Build log was saved at "file://c:\Users\Kelan Ige\Documents\Visual Studio 2005\Projects\Matrix Evaluator\Matrix Evaluator\Debug\BuildLog.htm"
1>Matrix Evaluator - 2 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
and here is the code:
CODE
// This program evaluates determinants of square matrices using minors.
//
// The program can handle up to nine by nine square matrices.
//
// This program reads input from a file and writes identical output to
// both the console and to a file.
//
// The program reads a matrix dimension and the required number of matrix
// elements, writes the matrix in columns, calculates the determinant,
// and writes the value of the determinant. The process repeats until
// an end of file is encountered or an invalid dimension is specified.
//
// After each determinant value is written a blank line is written.
//
// After all processing is completed, the termination message "Done."
// is written.
//
// If the input or output file cannot be opened, the program terminates without
// any other action than displaying an error message.
// Examples
//
// DETERMINANT EVALUATOR
//
// Matrix dimension:2
//
// Input values:
// 4.0000
// -3.0000
// 2.0000
// 6.0000
//
// Matrix:
// 4.0000 -3.0000
// 2.0000 6.0000
//
// Determinant value:30.0000
//
// Matrix dimension:4
//
// Input values:
// 0.1000
// 1.3000
// -3.5000
// 2.8000
// 1.7000
// -3.5000
// 2.4000
// -4.1000
// 2.3000
// 0.0000
// -1.6000
// 3.9000
// 1.2000
// -2.7000
// -0.5000
// 1.0000
//
// Matrix:
// 0.1000 1.3000 -3.5000 2.8000
// 1.7000 -3.5000 2.4000 -4.1000
// 2.3000 0.0000 -1.6000 3.9000
// 1.2000 -2.7000 -0.5000 1.0000
//
// Determinant value:-72.8371
//
// Done.
//#define SHOW_DETERMINANTS
#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>
using namespace std;
// **************************************************************************
// * *
// * GLOBAL CONSTANTS *
// * *
// *************************************************************************
const string INFILE_NAME = "File4.In";
const string OUTFILE_NAME = "File4.Out";
const int MAX_DIM = 9; // Maximum matrix dimension
const int PRECISION = 4; // Precision of double output
const int OUTPUT_WIDTH = 10; // Width of double output
// **************************************************************************
// * *
// * GLOBAL VARIABLES *
// * *
// **************************************************************************
ifstream fin; // Input file
ofstream fout; // Output file
bool ineof; // End of file indicator
// **************************************************************************
// * *
// * MAIN PROGRAM *
// * *
// **************************************************************************
int main()
{
// Function declarations
bool initialize(); // Initialize the program
bool getInput // Get the input matrix
(double mat[][MAX_DIM], // Matrix
int &dim); // Matrix dimension
void displayMatrix // Display the matrix
(double mat[][MAX_DIM], // Matrix
int dim); // Matrix dimension
double evaluate // Evaluate a determinant
(double mat[][MAX_DIM], // Matrix
int dim); // Matrix dimension
void finish(); // Terminate the program
bool process1; // Processing indicator
bool process2; // Processing indicator
int size; // Matrix dimension
double answer; // Value of determinant
double mat[MAX_DIM][MAX_DIM]; // Matrix
// Initialize
process1 = initialize();
// If the files were opened successfully
if (process1)
{
// Do
do
{
// Get the input equations
process2 = getInput(mat, size);
// If the input is valid
if (process2)
{
// Display the matrix
displayMatrix(mat, size);
// Evaluate the determinant
answer = evaluate(mat, size);
// Report the value of the determinant
cout << "Determinant value:" << answer << endl;
fout << "Determinant value:" << answer << endl;
// Write a blank line
cout << endl;
fout << endl;
}
}
// While the input is valid
while (process2);
// Finish
finish();
}
// Return
return 0;
}
// **************************************************************************
// * *
// * INITIALIZE FUNCTION *
// * *
// **************************************************************************
bool initialize() // Initialize program
{
bool success; // Initialization success indicator
// Set the success indicator false
success = false;
// Initialize the end of file false
ineof = false;
// Open the input file
fin.open(INFILE_NAME.c_str(), ios::in);
// If the file was not opened successfully
if (!fin)
{
// Set the end of file indicator true
ineof = true;
// Display an error message
cout << "ERROR: Unable to open input file \""
<< INFILE_NAME << "\"" << endl;
}
// Else
else
{
// Open the output file
fout.open(OUTFILE_NAME.c_str(), ios::out);
// If the output file was not opened successfully
if (!fout)
{
// Set the end of file indicator true
ineof = true;
// Close the input file
fin.close();
// Display an error message
cout << "ERROR: Unable to open output file \""
<< OUTFILE_NAME << "\"" << endl;
}
// If there is valid input
if (!ineof)
{
// Set the success indicator true
success = true;
// Set the output format
cout.setf(ios::fixed);
cout.setf(ios::showpoint);
cout.precision(PRECISION);
fout.setf(ios::fixed);
fout.setf(ios::showpoint);
fout.precision(PRECISION);
// Display a title
cout << "DETERMINANT EVALUATOR" << endl;
fout << "DETERMINANT EVALUATOR" << endl;
// Display a blank line
cout << endl;
fout << endl;
}
// Return the initialization success
return success;
}
// **************************************************************************
// * *
// * GET INPUT FUNCTION *
// * *
// **************************************************************************
bool getInput // Get the input matrix
(double mat[][MAX_DIM], // Matrix
int &dim) // Matrix dimension
{
bool valid; // Valid input indicator
int r; // Row number
int c; // Column number
int dimension; // Matrix Dimension
valid = false;// Set the valid input indicator false
cout << "Matrix dimension:"// Get the matrix dimension
cin >> dimension;
if (dimension <= 9) {// If the input is good
cout << "Matrix dimension:" << dimension << "." << endl;// Display a header for the matrix dimension
// Echo the input
// Display a blank line
if (dimension < 2) {// If the dimension is less than 2
cerr << "Error: Matrix dimension too small." << endl;// Display an error message
}// Display a blank line
else if (dimension > 9) {// Else if the dimension is too large
cerr << "Error: Matrix dimension too large." << endl;// Display an error message
}// Display a blank line
else {// Else
cout << "Input values:";// Display a header for the input values
// Enter the data for each row
// Enter the data for one row
// Get one matrix element
// If the input is good
// Echo the value
// If the input is all good
valid = true;// Set the valid input indicator true
// Display a blank line
// Return the result
return valid;
}
// **************************************************************************
// * *
// * DISPLAY MATRIX FUNCTION *
// * *
// **************************************************************************
void displayMatrix // Display the matrix
(double mat[][MAX_DIM], // Matrix
int dim) // Matrix dimension
{
int r; // Row number
int c; // Column number
// Display a matrix header
// Display all rows
// Display one row
// Display one matrix element
// End the line
// Display a blank line
}
// **************************************************************************
// * *
// * EVALUATE DETERMINANT FUNCTION *
// * *
// **************************************************************************
double evaluate // Evaluate a determinant
(double mat[][MAX_DIM], // Matrix
int dim) // Matrix dimension
{
return 0.0;
}
// **************************************************************************
// * *
// * FINISH FUNCTION *
// * *
// **************************************************************************
void finish() // Terminate the program
{
// Display a termination message
cout << "Done." << endl;
fout << "Done." << endl;
// Close the input file
fin.close();
// Close the output file
fout.close();
}
// **************************** SUPPORT FUNCTION ****************************
// **************************************************************************
// * *
// * DISPLAY DETERMINANT FUNCTION *
// * *
// **************************************************************************
void displayDeterminant // Display a determinant
(double mat[][MAX_DIM], // Matrix
int dim, // Matrix dimension
double det) // Value of determinant
{
int r; // Row number
int c; // Column number
// Display a matrix header
cout << "Determinant:" << endl;
fout << "Determinant:" << endl;
// Display all rows
for (r = 0; r < dim; r++)
{
// Display an initial bar
cout << "| ";
fout << "| ";
// Display one row
for (c = 0; c < dim; c++)
{
// Display one matrix element
cout << setw(OUTPUT_WIDTH) << mat[r][c];
fout << setw(OUTPUT_WIDTH) << mat[r][c];
}
// Display a terminal bar
cout << " |";
fout << " |";
// End the line on the console
cout << endl;
fout << endl;
}
// Display a blank line
cout << endl;
fout << endl;
// Display the determinant value
cout << "Subdeterminant value:" << det << endl;
fout << "Subdeterminant value:" << det << endl;
// Display a blank line
cout << endl;
fout << endl;
}
If possible could you also point me in the right direction as far as reading input for the values of a matrix from a text file. I'm having a hard time with file manipulation and reading elements into an array so that I can evaluate and find the determinate of the matrix. I know I haven't come close to a working program yet, but any thing you can tell me that would point me in the right direction for any of the code would be greatly appreciated.
Thanks in advanced.
14 Feb, 2008 - 06:37 PM
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