title: Undefined symbols for architecture x86_64:"cv::face::createFisherFaceRecognizer(int, double)", referenced from: _main in main.o
body: <p>I am working on facial recognition in video using opencv. I followed the tutorial on opencv's website(<a href="http://docs.opencv.org/modules/contrib/doc/facerec/tutorial/facerec_video_recognition.html" rel="nofollow noreferrer">http://docs.opencv.org/modules/contrib/doc/facerec/tutorial/facerec_video_recognition.html</a>). I get following error when I try to build my code in xcode.</p>
  
  <p>Undefined symbols for architecture x86_64:
    "cv::face::createFisherFaceRecognizer(int, double)", referenced from:
        _main in main.o
  ld: symbol(s) not found for architecture x86_64
  clang: error: linker command failed with exit code 1 (use -v to see invocation).</p>
  
  <p>I made a few changes to the code as given in here <a href="https://stackoverflow.com/questions/29806834/fatal-error-opencv2-contrib-contrib-hpp-file-not-found-open-cv-already-built/29806967#29806967">fatal error: opencv2/contrib/contrib.hpp&#39; file not found (open cv already built)</a></p>
  
  <p>Please guide me through it as I am new to opencv.</p>
  
  <p>Thanks in advance!</p>