sortFunction_for_std::vector_in_UserDefinedClass

[madi09]

I have this class:

class QSweep{

public:
QSweep(const vector< vector<double> >& myPoints, const vector< vector<int> >&myEdges);

void intersection(vector< vector<double> >& myPoints, vector< vector<int> >& myEdges);
vector< vector<int> >* sortEdges(vector< vector<double> >& myPoints,
vector<vector<int>>& myEdges);

bool sortx(const vector< vector<int> >& edge1, const vector< vector <int> >& edge2) {
return edge1[0][0]< edge2[0][0];
};
private:
vector< vector<double> > myPoints_;
vector< vector<int> > myEdges_;
};

The constructor creates the desired data structure in this way:
QSweep::QSweep(const vector< vector<double> >& myPoints, const vector< vector<int> >& myEdges){
myPoints_=vector< vector<double> > (myPoints.size(), vector< double >(3,0));
for (unsigned int i=0;i<myPoints.size();i++){
myPoints_[i][0]=myPoints[i][0];
myPoints_[i][1]=myPoints[i][1];
myPoints_[i][2]=myPoints[i][2];
}

myEdges_=vector< vector<int> > (myEdges.size(), vector< int >(2,0));
for (unsigned int i=0;i<myEdges.size();i++){
myEdges_[i][0]=myEdges[i][0];
myEdges_[i][1]=myEdges[i][1];
}
}

giving E.g:
myPoints={{1.0,1.0,2.0},{18.0,4.0,2.0},{5.0,1.0,2.0}};
myEdges={{0,1},{1,2},{0,2}};

I want to have a sort function for myEdges 2-dimensional vector depending on the first coordinate of myPoints given by myEdges[i][0].E.g after sorting myEdges would become
myEdges={{0,1},{0,2},{1,2}} because
myPoints[myEdges[1][0]][0]<myPoints[myEdges[2][0]][0].

I tried:
bool sortx(const vector<int> & edge1,const vector<int> & edge2) {
return myPoints_[edge1[0][0]< myPoints_[edge2[0][0];
};
in the public member of QSweep
with the call:
int main(){
...
sort(myVector1.begin(),myVector1.end(),sortx);
}
but I keep having the same error (even if I modified something):
sort.cpp: In static member function 'static bool QSweep::sortx(const std::vector<int, std::allocator<int> >&, const std::vector<int, std::allocator<int> >&)':
sort.cpp:47: error: invalid use of member 'QSweep::myPoints_' in static member function
sort.cpp:25: error: from this location
sort.cpp:47: error: invalid use of member 'QSweep::myPoints_' in static member function
sort.cpp:25: error: from this location
sort.cpp: In function 'int main()':
sort.cpp:106: error: 'sortx' was not declared in this scope

If I used change it in:
bool sortx(const vector<int> & edge1,const vector<int> & edge2) {
return edge1[0]< edge2[0];
};

I have never used vector containers before and clearly I dont surely understand how they work.
Can I just use also the members of the class myPoints when defining the sortx function.
And even without it I can see I still have an error.
Maybe the call to the sort is not good?
what am I possibly doing wrong?
Thank you in advance for your suggestions (remarks or comments, documentation on subject).

[jsmith]

The compiler error does not match the code you've posted. Can you post the code that generates that compile error? Also, use code tags (the # to the right) so it is formatted nicely.