anchor.diff:      ${NB_USER}
   
   #====================================================================================
  -# libpng15 (needed by pyferret)
  -
  -#USER root
  -#WORKDIR /opt
  -#RUN wget --no-check-certificate https://sourceforge.net/projects/libpng/files/libpng15/1.5.30/libpng-1.5.30.tar.gz && \
  -#    tar xvfz libpng-1.5.30.tar.gz
  -#RUN cd libpng-1.5.30 && \
  -#    ./configure --prefix=/usr/local/libpng && \
  -#    make check && \
  -#    make install
  -#
  -#ENV LD_LIBRARY_PATH="/usr/local/libpng/lib:${LD_LIBRARY_PATH}"
  -
  -#====================================================================================
   # pyferret installation
   
   USER root
   WORKDIR /opt
  -RUN wget https://github.com/NOAA-PMEL/PyFerret/releases/download/v7.5.0/PyFerret-7.5.0-RHEL7-64-Python2.7.tar.gz && \
  -    tar xvfz PyFerret-7.5.0-RHEL7-64-Python2.7.tar.gz
   RUN git clone https://github.com/NOAA-PMEL/FerretDatasets && \
       mv FerretDatasets fer_dsets
   
  
positive.code: 
  #====================================================================================
  RUN apt-get update && apt-get -y install wget git
  #RUN apt-get update && apt-get -y install libgfortran3
  RUN apt-get update && apt-get -y install r-base
  
  RUN pip install notebook
  RUN pip install numpy pandas bokeh
  
negative.code: RUN git clone https://github.com/PBrockmann/fast
  
  #====================================================================================
  ENV FER_DIR="/opt/"
  ENV FER_DSETS="/opt/fer_dsets"
  
  ENV PYTHONPATH="${FER_DIR}/lib/python3.6/site-packages:${PYTHONPATH}"
  ENV LD_LIBRARY_PATH="${FER_DIR}/lib/python3.6/site-packages/pyferret:${LD_LIBRARY_PATH}"
  
  ENV FER_DATA=". ${FER_DSETS}/data ${FER_DIR}/contrib /opt/fast"
  ENV FER_DESCR=". ${FER_DSETS}/descr"
  