Vector sort with a struct?

[{AGUT2} {H}-IWIK]

Guys, I have these headers:
#include <stdlib>
#include <math>
#include <iostream>
#include <iomanip>
#include <fstream>
#include <vector>
#include <string>
#include <algorithm>

*amongst others) and a a data structure:

// Creates part of basic framework of the output numbering system
struct vertexPoints {
int num;
double xc;
double yc;
double zc;
};

from this, I have created a vector

vector<vertexPoints> myPoints;

with vertices push_back()'ed onto it. I want to be able to sort this -
mainly by x, but ideally by x, then y, then z.

if I type mypoints.sort(myPoints.begin(), myPoints.end, comparex);

with

bool comparex(myPoints& x, myPoints& y)
{
return x.xc < y.xc;
}

the compiler throws a tantrum saying that sort is not a member function of
the vertex<myPoints> vector.

What am I doing wrong?

TIA,

Alex.

--
Reply to:alex an.ti livingstone sp@am btinternet.com cutting the usual...

[tom_usenet]

On Fri, 12 Sep 2003 12:39:26 +0100, {AGUT2} {H}-IWIK
<al********************@ambtinternet.com> wrote:

Guys, I have these headers:
#include <stdlib>
#include <math>
#include <iostream>
#include <iomanip>
#include <fstream>
#include <vector>
#include <string>
#include <algorithm>

*amongst others) and a a data structure:

// Creates part of basic framework of the output numbering system
struct vertexPoints {
int num;
double xc;
double yc;
double zc;
};

from this, I have created a vector

vector<vertexPoints> myPoints;

with vertices push_back()'ed onto it. I want to be able to sort this -
mainly by x, but ideally by x, then y, then z.

if I type mypoints.sort(myPoints.begin(), myPoints.end, comparex);
std::sort(myPoints.begin(), myPoints.end, comparex);

with

bool comparex(myPoints& x, myPoints& y)
bool comparex(myPoints const& x, myPoints const& y)

{
return x.xc < y.xc;
}

the compiler throws a tantrum saying that sort is not a member function of
the vertex<myPoints> vector.

Sort is not a member of vector, it is a namespace std function.

Tom

[Peter Kragh]

"tom_usenet" <to********@hotmail.com> wrote in message
news:u9********************************@4ax.com...

On Fri, 12 Sep 2003 12:39:26 +0100, {AGUT2} {H}-IWIK
<al********************@ambtinternet.com> wrote:

Guys, I have these headers:
#include <stdlib>
#include <math>
#include <iostream>
#include <iomanip>
#include <fstream>
#include <vector>
#include <string>
#include <algorithm>

*amongst others) and a a data structure:

// Creates part of basic framework of the output numbering system
struct vertexPoints {
int num;
double xc;
double yc;
double zc;
};

from this, I have created a vector

vector<vertexPoints> myPoints;

with vertices push_back()'ed onto it. I want to be able to sort this -
mainly by x, but ideally by x, then y, then z.

if I type mypoints.sort(myPoints.begin(), myPoints.end, comparex);
std::sort(myPoints.begin(), myPoints.end, comparex);

Should probably be:

std::sort(myPoints.begin(), myPoints.end(), comparex);

with

bool comparex(myPoints& x, myPoints& y)
bool comparex(myPoints const& x, myPoints const& y)

Try:

bool comparex(const vertexPoints& x, const vertexPoints& y)

instead.

{
return x.xc < y.xc;
}

the compiler throws a tantrum saying that sort is not a member function ofthe vertex<myPoints> vector.

Sort is not a member of vector, it is a namespace std function.

Tom

You could also consider making a "bool operator<(const vertexPoints&)" in
your vertextPoints struct. Then you could use the sort function like this:

std::sort(myPoints.begin(), myPoints.end());

That is IMHO a more object oriented way of doing this.

BR,
Peter Kragh