Q:

Makefile is not working

I am trying to get my makefile working, but it is giving me some errors and I can't get it to work. 
 OBJS = Kmeans.o cluster.o data.o 
    CC = g++
    DEBUG = -g
    CFLAGS = -Wall -c $(DEBUG)
    LFLAGS = -Wall $(DEBUG)

    clustering : $(OBJS)
        $(CC) $(LFLAGS) $(OBJS) -o clustering

    Kmeans.o : Kmeans.h Kmeans.cpp cluster.h data.h
        $(CC) $(CFLAGS) Kmeans.cpp

cluster.o : cluster.h cluster.cpp data.h 
    $(CC) $(CFLAGS) cluster.cpp

data.o : data.h data.cpp 
    $(CC) $(CFLAGS) data.cpp

clean:
    \rm *.o *~ clustering

And the files are:
clustering.cpp -> #include "Kmeans.h"
Kmeans.cpp     -> #include "Kmeans.h"
Kmeans.h       -> #include "cluster.h"
cluster.cpp    -> #include "cluster.h"
cluster.h      -> #include "data.h"
data.cpp       -> #include "data.h"

What am I doing wrong? 
Edit:
Sorry, I forgot to include the errors:
Kmeans.o: In function `Kmeans::read(char*)':
Kmeans.cpp:(.text+0x53c): undefined reference to `Data::~Data()'
cluster.o: In function `Cluster::Cluster(int, int, int)':
cluster.cpp:(.text+0x45): undefined reference to `Data::~Data()'
cluster.cpp:(.text+0x80): undefined reference to `Data::~Data()'
cluster.o: In function `Cluster::Cluster()':
cluster.cpp:(.text+0xca): undefined reference to `Data::~Data()'
cluster.cpp:(.text+0x110): undefined reference to `Data::~Data()'
cluster.o: In function `Cluster::setData(int, int, int)':
cluster.cpp:(.text+0x158): undefined reference to `Data::~Data()'
collect2: ld devolvió el estado de salida 1
make: *** [clustering] Error 1

Thanks! 
I compile each file and the problem is in the last line:
g++    -c -o clustering.o clustering.cpp
g++    -c -o data.o data.cpp
g++    -c -o Kmeans.o Kmeans.cpp
g++    -c -o cluster.o cluster.cpp
g++    -o clustering clustering.o data.o Kmeans.o cluster.o    <----

A:

It seems that you have Data::~Data declaration in data.h and you do not have definition anywhere.  
Just remove the declaration from header or add empty definition it it's a virtual destructor.