I am trying to define centroid in the following code as centroid is part of the private data for this class. But when I output the data it reads 0, 0 instead of the real values. Vec is a 3 dimension class that i have created. I'm not sure what could be wrong.. Help!!

Header file:

//////////////////////////////////////////////////
/// \class triangle
/// \brief triangle class
/// ///////////////////////////////////////////////
/// \file triangle.h
/// \brief provide a set fo functions to facilitate triangle manipulations
//////////////////////////////////////////////////

#include <math.h>
#include <iostream>
#include <fstream>
#include "list.h"
#include "vec.h"
#include "circle.h"
using namespace std;

#ifndef TRIANGLE_H
#define TRIANGLE_H

class triangle : public ListElement
{
public:

    friend ostream & operator << (ostream& out, const triangle& inTriangle);

    virtual double ElementValue(void);

    /// \brief Non-default Constructor
    triangle(const unsigned int id_in, const Vec iIn, const Vec jIn, const Vec kIn, 
             const Vec triNodeIDin);

    /// \brief Destructor
    ~triangle(){};

    /// \brief Calculate the centroid of a triangle
    Vec get_centroid(void){return centroid;}

    /// \brief Calculate the area of a triangle
    double get_area(void){return area;}

    /// \brief Prints out the triangle area
    virtual void print(void) {cout << "Tri area: " << ElementValue() << endl;}

    /// \brief Writes out the triangle data
    virtual void out(ofstream& myfile);

private:
    unsigned int id;
    Vec i; /// <First node of triangle
    Vec j; /// <Second node of triangle
    Vec k; /// <Third node of triangle
    Circle theCircle;
    Vec centroid;
    double area;
    Vec triNode;
};

#endif // TRIANGLE_H

The source file constructor:

triangle::triangle(unsigned int id_in, Vec iIn, Vec jIn, Vec kIn, Vec triNodeIDin): 
        id(id_in), i(iIn), j(jIn), k(kIn),theCircle(iIn, jIn, kIn), triNode(triNodeIDin){

    /// Method:
    /// -Takes in nothing
    /// -Calculate the area of a triangle using vectors
    /// \param void
    /// \return area of the triangle

    Vec vecA(i[0], i[1], 0);
    Vec vecB(j[0], j[1], 0);
    Vec vecC(k[0], k[1], 0);
    Vec vecAB = vecA-vecB;
    Vec vecAC = vecA-vecC;
    area = ((vecAB*vecAC).norm())*0.5;

    /// Method:
    /// -Takes in nothing
    /// -Compute the x, y coordinates of the centroid
    /// \param void
    /// \return centroid of a triangle

    double cX = (i[0]+j[0]+k[0])/3;
    double cY = (i[1]+j[1]+k[1])/3;
    double cZ = 0;
    centroid(cX, cY, cZ);
}

I think you'll have to share your Vec class and your display code to get the proper help. Maybe someone else can figure something out from this, but I can't.

The call to the centroid constructor on Line 26 concerns me. It probably has something to do with that, but I'm not sure.

It too depends on your output method.Try posting it