"Undefined Reference" error when trying to link to external library

[duegogo]

Hello, so I'm trying to learn how to use external functions and wrote the following dummy function:

#include "vertex.h"
#include <iostream>
using namespace std;
using namespace MTKpp;
int main()
{
        vertex* a;
        a->setName("blah");
        cout << a->getName() << endl;
        return 0;
}

But when I try to make this file, I get "undefined reference" errors

main.cpp:(.text+0x4c): undefined reference to `MTKpp::vertex::setName(std::basic_string<char, std::char_traits<char>, std::allocator<char> >)'
main.cpp:(.text+0x74): undefined reference to `MTKpp::vertex::getName()'

and this is what my makefile looks like:

all: run
run: main.o
        g++ main.o -o run
main.o: main.cpp
        g++ -I/home/me/Desktop/me/mtkpp/src/Graph -L/home/me/Desktop/me/mtkpp/src/Graph/.libs/ -lGraph -c main.cpp

clean:
        rm -rf *o run 

I have a hunch that something is wrong with my makefile, since it is my first time attempting this. But the vortex.h is in /home/me/Desktop/me/mtkpp/src/Graph and the graph library is in /home/me/Desktop/me/mtkpp/src/Graph/.libs/. So if I understand this correctly, -L in conjunction with -l will tell my compiler to look for the libGraph.a/libGraph.so inside the -L library directory, and the -I I put in there so my compiler could find the "vortex.h" file. But alas, it doesn't work. And since vertex.h only includes

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <map> 

I assume g++ knows where to look for them without needing me to specify it in the makefile?

[Moschops]

Your makefile does look confused. You've put the linking details in your instructions of how to make main.o - making main.o is what you do before the linking (-c is the switch that actually explicitly tells your compiler NOT to do any linking). The linking details should go in the instructions of how to make the output executable.

[duegogo]

So did you mean something like this:

all: run
run: main.o
        g++ -L/home/me/Desktop/me/mtkpp/src/Graph/.libs/ -lGraph main.o -o run
main.o: main.cpp
        g++ -I/home/me/Desktop/me/mtkpp/src/Graph -c main.cpp
clean:
        rm -rf *o run 

This makes sense to me because the -c suppresses the linking so it won't complain about missing libraries, and then it will resolve everything at the run: main.o step. But it is still giving me

main.o: In function `main':
main.cpp:(.text+0x19): undefined reference to `MTKpp::vertex::vertex()'
main.cpp:(.text+0x50): undefined reference to `MTKpp::vertex::setName(std::basic_string<char, std::char_traits<char>, std::allocator<char> >)'
main.cpp:(.text+0x78): undefined reference to `MTKpp::vertex::getName()'
main.cpp:(.text+0xb9): undefined reference to `MTKpp::vertex::~vertex()'
main.cpp:(.text+0xff): undefined reference to `MTKpp::vertex::~vertex()'

when I make it. So I'm wondering if this looks right or if I am missing something subtle still?