: GEMPAK and AWIPS

System Python (2.7+)

Prerequisites

 sudo yum install python-devel python-setuptools
 sudo /bin/easy_install pip
 sudo pip install python-awips numpy

Source Gemenviron.build

(after you’ve sourced Gemenviron.profile)
```
 cd GEMPAK7
 . Gemenviron.build
```

Confirm Python definitions

 env |grep PY
    
 PYDEP=-lpthread -ldl -lutil
 PYHOME=/usr
 WITHPY=-DWITHPYTHON
 PYLIB=-lpython2.7
 PYTHONPATH=/usr/lib64/python2.7/site-packages:/usr/lib/python2.7/site-packages:/home/awips/GEMPAK7/scripts/python
 PYINC=-I/usr/include/python2.7

Run make all and make install in GEMPAK7/gempak

 cd $NAWIPS
    
 make all 2>&1 | tee -a make.log
    
 make install

Confirm linked Python in the new $OS_BIN executables

 ldd $OS_BIN/gdinfo
 
 	linux-vdso.so.1 =>  (0x00007ffde81f9000)
     libpython2.7.so.1.0 => /usr/lib64/libpython2.7.so.1.0 (0x00007f3168f5e000)
     libpthread.so.0 => /usr/lib64/libpthread.so.0 (0x00007f3168d41000)
     libdl.so.2 => /usr/lib64/libdl.so.2 (0x00007f3168b3d000)
     libutil.so.1 => /usr/lib64/libutil.so.1 (0x00007f316893a000)
     libgfortran.so.3 => /usr/lib64/libgfortran.so.3 (0x00007f3168617000)
     libm.so.6 => /usr/lib64/libm.so.6 (0x00007f3168315000)
     libgcc_s.so.1 => /usr/lib64/libgcc_s.so.1 (0x00007f31680ff000)
     libquadmath.so.0 => /usr/lib64/libquadmath.so.0 (0x00007f3167ec2000)
     libc.so.6 => /usr/lib64/libc.so.6 (0x00007f3167b00000)
     /lib64/ld-linux-x86-64.so.2 (0x00007f3169325000)

AWIPS Python

Install

Install all of the packages in the AWIPS Python group (or the awips2-server or awips2-cave groups) to install AWIPS Python 2.7
```
 sudo yum groupinstall awips2-python
    
    
    
    
 sudo yum install awips2-gempak
```
This will install the awips2-python-setuptools package.
Source Gemenviron.profile
```
 cd GEMPAK7
 . Gemenviron.profile
```

Run

gdinfo

  GDFILE   = A2GFS20
  LSTALL   = YES
  OUTPUT   = T
  GDATTIM  = LAST
  GLEVEL   = 500
  GVCORD   = PRES
  GFUNC    = T
  r
     
 Server =  edex-cloud.unidata.ucar.edu
 Table =  grid
 MODEL =  GFS20

CentOS/RHEL 7 w Python 2.7

Install on CentOS/RHEL

pip install python-awips numpy

AWIPS Database Grid Names

For GDFILE

A2GFS
A2GFS20
A2NAM12
A2RAP13

Example

gdinfo

   GDFILE   = A2GFS20
   LSTALL   = YES
   OUTPUT   = T
   GDATTIM  = LAST
   GLEVEL   = 500
   GVCORD   = PRES
   GFUNC    = T
   r
     
   Requesting from edex.unidata.ucar.edu
  Server =  edex.unidata.ucar.edu
  Table =  grid
  MODEL =  GFS20

Creating process: gplt for queue 0 Creating process: gif for queue 32769 Requesting from edex-cloud.unidata.ucar.edu Traceback (most recent call last): File “/home/awips/GEMPAK7/scripts/python/GridInfoRetriever.py”, line 5, in from awips import ThriftClient ImportError: No module named awips Traceback (most recent call last): File "/home/awips/GEMPAK7/scripts/python/GridInfoRetriever.py", line 5, in from awips import ThriftClient ImportError: No module named awips Traceback (most recent call last): File "/home/awips/GEMPAK7/scripts/python/GridNavRetriever.py", line 4, in from awips import ThriftClient ImportError: No module named awips Traceback (most recent call last): File "/home/awips/GEMPAK7/scripts/python/GridNavRetriever.py", line 4, in from awips import ThriftClient ImportError: No module named awips

Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

Backtrace for this error: #0 0x7F740049E467 #1 0x7F740049EAAE #2 0x7F73FF9A466F #3 0x458E0E Segmentation fault [awips@edex-el7 ~]$

#

Remote AWIPS data retrieval must be built into GEMPAK. The GEMPAK binary is not built against Python due to the potential problem encountered when dynamically linking against libpython2.6.so or libpython2.7.so, but the binary installation can be easily updated with a new source build:

Source Gemenviron.build

(after you’ve sourced Gemenviron.profile)
```
 cd $NAWIPS
 . Gemenviron.build
```

Confirm Python definitions

 env |grep PY
    
 PYDEP=-lpthread -ldl -lutil
 PYHOME=/usr
 WITHPY=-DWITHPYTHON
 PYLIB=-lpython2.6
 PYTHONPATH=/usr/lib64/python2.6/site-packages:/usr/lib/python2.6/site-packages:/home/awips/GEMPAK7/scripts/python
 PYINC=-I/usr/include/python2.6

Example shows CentOS/RHEL 6 using Python 2.6.

Run make all and make install in GEMPAK7/gempak

 cd $NAWIPS
    
 make all 2>&1 | tee -a make.log
    
 make install

Confirm linked Python in the new $OS_BIN executables

 ldd $OS_BIN/gdinfo
 	linux-vdso.so.1 =>  (0x00007fffc8be5000)
     libpython2.6.so.1.0 => /usr/lib64/libpython2.6.so.1.0 (0x0000003b68200000)
     libpthread.so.0 => /lib64/libpthread.so.0 (0x0000003b5ce00000)
     libdl.so.2 => /lib64/libdl.so.2 (0x0000003b5d200000)
     libutil.so.1 => /lib64/libutil.so.1 (0x0000003b6ba00000)
     libgfortran.so.3 => /usr/lib64/libgfortran.so.3 (0x00007ff7ef266000)
     libm.so.6 => /lib64/libm.so.6 (0x0000003b5ca00000)
     libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x0000003b66600000)
     libc.so.6 => /lib64/libc.so.6 (0x0000003b5c600000)
     /lib64/ld-linux-x86-64.so.2 (0x0000003b5c200000)

Install with AWIPS

GEMPAK 7.3.1 includes a bundled libpython2.7.so.1.0, which many programs link against (for example, see ldd $OS_BIN/gdinfo), and this library is required for these program to run, but AWIPS python is not required unless you request A2 data sources. Making a request for GDFILE = A2NAM12, for example, results in the following error:

Requesting from edex.unidata.ucar.edu
Could not find platform independent libraries <prefix>
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
ImportError: No module named site

While GDFILE = GFS (which resolves to $GEMDATA/model) would run as expected on a local data file.

As part of the migration from NAWIPS to AWIPS (II), the users will no longer have GEMPAK data management files created for use in operations. All data will be retrieved from the AWIPS database.

The changes in v7.0.0 only apply to applications that read data. Any of the programs that write data to GEMPAK files will not write to the A2DB. The following is a list of the applications that may access the A2DB: ● Surface (SF) ○ SFGRAM - plot meteorograms ○ SFL604/SFLIST - list surface observations in different tabular formats ○ SFMAP - plot surface observations on a map ● Sounding (SN) [Upper Air] ○ SNCROSS - plot a spatial or temporal cross-section ○ SNHODO - plot a hodograph ○ SNLIST - list the upper air observations ○ SNMAP - plot upper air observations on a map ○ SNPROF - plot a sounding profile/SKEW-T ○ SNTSER - plot a time series of an upper air data parameter ● Grid (GD) ○ GDCNTR - plot contours on a map ○ GDCROSS - plot a spatial cross-section ○ GDLIST - list grid point data ○ GDMAP - plot grid point values on a map ○ GDPLOT/GDPLOT2/GDPLOT3 - plot contours, vectors, point data, streamlines as appropriate for the type of data ○ GDPROF - plot a sounding profile/SKEW-T at a grid point ○ GDSTREAM - plot streamlines on a map ○ GDTHGT - plot a temporal cross-section ○ GDTSER - plot a time series at a grid point ○ GDWIND - plot vectors on a map

Adding or Modifying a Data Set In order to access data from the A2DB, use the standard SFFILE, SNFILE and GDFILE application parameters. These parameters allow the use of aliases to represent files or collections of files. This functionality has been extended to reference the control files, which define the attributes for connecting to, and reading from, the A2DB. The aliases are defined in $GEMTBL/config/datatype.tbl. For a new entry in the DataType table, most of the values can be copied from a corresponding entry that references an actual directory and file. The differences are in the PATH and FILE TEMPLATE. The path will always be AWIPSDB and the file will be the name of the control file. All of the control files reside in $GEMTBL/data-access. For example, the entry for METAR data from the A2DB begins with: A2METAR AWIPSDB metar.xml ……… The remainder of the line is identical to the regular METAR alias. After adding a new entry in the DataType table, the XML control file must be created. The control file equates the A2DB meta information to the required GEMPAK information for defining the contents of a “data file”. GEMPAK Surface, Sounding and Grid files have header values that identify the type of file and how to read the subsequent data. The control file is configured to specify the Python scripts that will request the appropriate header information and how that information is returned to the GEMPAK applications. At present, adding new point data types requires some knowledge of the contents of the A2DB in order to configure the list of data fields. Adding new grid data sets is much easier, but does require the name of the grid data in the A2DB. For example, the GFS model is stored as “GFS230” and the NAM model is stored as “nam”. Note that one is uppercase and one is lowercase. Until a utility can be written to provide the required information, please see your local AWIPS Administrator to help gather this information.

Suggested Installation for the AWIPS Environment The following configuration is used on NTBN, OPCN and HPCN. It allows for easy updating, but does require a separate user account to store the NAWIPS/GEMPAK tables, libraries and binaries. 1. If it does not exist, create a user account named “gempak”. Log into the “gempak” account. 2. Get the source tar file from the download web site above and transfer it to the AWIPS system. 3. Sample .cshrc and .profile files may also be found on the download site. 4. Make a directory for the current release (i.e., mkdir v7.0.0) in $HOME. 5. Go to the release directory and unpack the source tar file. 6. Follow the build instructions above. The current data flow paradigm for the AWIPS does not provide for creating or transferring GEMPAK files to the AWIPS system. Therefore, all of the data-related environment variables will not be used. Any data access, while on an AWIPS system, will be through the database. Sample entries for the data types are in $GEMTBL/config/datatype.tbl and the XML control files are in $GEMTBL/data-access/*.xml.