How to build PyNIO from source code

See the full instructions for building NCL from source code. NCL is a difficult package to build, so we recommend going the binary distribution route if possible.

If you link against a precompiled version of NCL, note that it will probably have GRIB2, HDF-EOS2, and NetCDF4 support enabled, so you will need to build these additional software packages before you build PyNIO from source code.

Note that many of the instructions for building external software for NCL will also apply for PyNIO, so you don't need to follow these instructions twice. Don't fret if you can't get the "ncl" executable in $NCARG/ni/src/ncl to build; it is not needed by PyNIO. You basically need "libnio.a" and some include files from that directory.

Make sure the NCARG_ROOT environment variable is set to the root directory of where this software was installed.

Download version 3.6.3 or later. (Do not download version 4.x.x.)

Once you have the netCDF source code, you can build and install it with:

  ./configure --prefix=/usr/local
  make all install

Download version 6b or later.

Once you have the jpeg source code, you can build and install it with:

  ./configure --prefix=/usr/local
  make all install install-lib install-headers

Download version 1.2.3 or later.

Once you have the zlib source code, you can build and install it with:

  ./configure --prefix=/usr/local
  make all install

Download version 1.2.27 (earlier versions had a serious bug) or later.

Once you have the libpng source code, build and install it with:

  ./configure  --with-pic --disable-shared --prefix=/usr/local 
  make all install

Download version 4.1 or later (do not download version 5.x.y). Important note: Normally the HDF include files get installed to "$prefix/include". Since this will cause some netCDF include files to get overwritten, you must use the "--includedir" option to install the HDF include files to "$prefix/include/hdf" instead.

For versions older than 4.2r2, make sure the environment variable 'CFLAGS' has -DHAVE_NETCDF included (you can remove it after you are done with this build, but it won't hurt the other builds). For example:

  export CFLAGS="$CFLAGS -DHAVE_NETCDF"

  setenv CFLAGS "$CFLAGS -DHAVE_NETCDF"

 ./configure --prefix=/usr/local --with-zlib=/usr/local \
       --with-jpeg=/usr/local --includedir=/usr/local/include/hdf 
  make all install

For versions 4.2r2 and higher:

It's not necessary to alter the 'CFLAGS' environment variable to build this version. Instead, use the --disable-netcdf option:

 ./configure --prefix=/usr/local --with-zlib=/usr/local \
       --with-jpeg=/usr/local --includedir=/usr/local/include/hdf \
       --disable-netcdf
  make all install

Download and build optional external software, if needed

Important note: if you are linking against a pre-built version of NCL, it may have the following packages built into its libraries, and hence the following software will not be optional.

If you need support for reading GRIB2 files, then you will need to download and install the following packages:

• Jasper - Download version 1.900 or later.

  Once you have the Jasper source code, you can build and install it with:

    ./configure --prefix=/usr/local
    make all install
  

• g2clib - Download version 1.0.4 or later. There's a bug in version 1.0.4, so additionally download a modified version of the file "g2_unpack2.c" and put it in the "g2clib-1.0.4" directory. If you download a different version of g2clib, be sure you incorporate the changed g2_unpack2.c file, rather than just copying it over.

  Once you have the g2clib source code and the modified file, make changes to "makefile" to:

  1. change the compiler (CC line) and flags (CFLAGS lines)
  2. make sure the DEFS line has both "-DUSE_JPEG2000" and "-DUSE_PNG"
  3. add the appropriate location of the Jasper/libpng include files to the "INC" line

  Now type:

    make all
    cp libgrib2c.a /usr/local/lib
    cp grib2.h /usr/local/include
  

If you need support for reading HDF-EOS 2 files, then you will need to download and install the following packages:

• HDFEOS 2 - Download version 2.14.v1 or later. You may need to edit the file "bin/INSTALL-HDFEOS" to make sure it uses the correct compilers and compile options. Then run:

    bin/INSTALL-HDFEOS
  

  Answer questions about location of HDF-4 lib and include files. You must specify the "hdf" subdir for the include directory (for example, "/usr/local/include/hdf").

  Pay attention to where "libhdfeos.a" file gets installed under the hdfeos/lib directory, and copy this file to your library installation directory. Do the same for the include files. Do not copy libGctp.a! For example, on a linux machine, you would type:

    cp lib/linux/libhdfeos.a /usr/local/lib/.
    cp include/*.h /usr/local/include/.
  

• gctp - this source should be part of the HDF-EOS2 software you just downloaded, in a directory "gctp/src".
  • cd gctp/src

  • Copy the appropriate makexxxx file to "makefile".

  • Make "makefile" writable:

      chmod u+rw makefile
    

  • Edit "makefile" and change LIBDIR appropriately (/usr/local/lib), and change the library name from "libgctpxxxx.a" to "libGctp.a" in all locations in this file (there's more than one reference).

  • Copy some include files to the same directory you're in:

      cp ../include/*.h .
    

  • Type:

      make
    

This build will overwrite a NetCDF-3 installation if you have one.

If you need support for reading/writing classic NetCDF-4 files, then you will need to download and install the following packages:

• szip - Download version 2.0 or later.

    ./configure --prefix=/usr/local  --disable-shared
    make all install >& make-output
  

• HDF5 - Download version 1.8.1 or later.

    ./configure --with-zlib=/usr/local --with-szlib=/usr/local --prefix=/usr/local --disable-shared
    make all install >& make-output
  

• NetCDF-4 - Download version 4.0 or later.

    ./configure --with-hdf5=/usr/local --with-zlib=/usr/local --with-szlib=/usr/local --prefix=/usr/local --disable-f90 \
         --enable-netcdf-4
    make all install >& make-output
  

Download the source code for PyNIO

To download the PyNIO source code, follow the instructions at:

http://www.pyngl.ucar.edu/Download/

  gunzip PyNIO-1.3.0b1.tar.gz
  tar -xvf PyNIO-1.3.0b1.tar

Set environment variables if necessary

Then, depending on what optional packages (GRIB2, NetCDF-4, HDFEOS) you decided to install, you will need to set some environment variables so the PyNIO installation knows about them.

If you link against a precompiled version of NCL, note that it will probably have GRIB2, HDF-EOS2, and NetCDF4 support enabled. Thus you will need to read the next paragraph about setting certain environment variables to "1", and you will need to build the external software required from source code.

First, you need to set one or more of the following environment variables to "1" if you build this software package and want to include it in PyNIO:

setenv HAS_GRIB2 1
setenv HAS_HDFEOS 1
setenv HAS_NETCDF4 1

GRIB2_PREFIX
HDFEOS_PREFIX
NETCDF4_PREFIX

Finally, you may need to help the PyNIO installation find the location of any system Fortran libraries needed to resolve symbols between C and Fortran code. For example, "-lgfortran" is needed if you built the software with gfortran, "-lg2c" if g77 was used, and "-lf95" for g95. Use F2CLIBS to indicate the library name (don't include the "-l"), and F2CLIBS_PREFIX to point to the location. For example:

setenv F2CLIBS gfortran
setenv F2CLIBS_PREFIX /usr/local/lib

Execute the 'setup.py' script

python setup.py install

If you have problems, send email to pyngl-talk (you must be a member to post). We will add a trouble-shooting guide once we see what kind of problems people have.