analogRead return 0 in a library

i want to create a library for a project, and i have to do a analogRead at one moment. I created a library for this, and it compile without any errors. But when i want to call this function, it return me 0, but it is working fine in the .ino file..

Here are my files :

the .ino file

#include <Filoguidage.h>
Filoguidage filoguidage;
int pin = A11;

void setup() {
  Serial.begin(115200);
  pinMode(pin,INPUT);
  filoguidage.init(pin,10,10);
}
void loop() {
  int test = filoguidage.getPosition();
  Serial.println(test);
}

The .h of my library :

#ifndef Filoguidage_h
#define Filoguidage_h
#include "Energia.h"
class Filoguidage
{
    public:
        void init(int PinCapteur,int valeurCentrale, int interval);
        int getPosition();

    private:
        int _PinCapteur;

};
#endif

And finally the .cpp :

#include "Energia.h"
#include "Filoguidage.h"


void Filoguidage::init(int PinCapteur,int valeurCentrale,int interval){
  int _PinCapteur = PinCapteur;
    pinMode(_PinCapteur, INPUT);
}
int Filoguidage::getPosition(){
  return analogRead( _PinCapteur );
}

I think thats because pinMode and analogRead are not recognized, but i don't know how to solve it. If somebody can help me i would be very happy, thanks