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Usage Example
Using fimex as opendap-client
Install netcdf with integrated dap-support
Prerequisites
- netcdf4 (4.1.1) from unidata
- curl library:
sudo apt-get install libcurl4-gnutls-dev
(on ubuntu hardy) - make sure to remove the libnetcdf4-dev package (on ubuntu hardy):
apt-get remove libnetcdf4-dev
Build
Configuring, without HDF-file support (can be added if desired). Important: include dap-support via curl; build shared libraries (libtool autodetect dependencies)
./configure --prefix=/usr/local/netcdf4.1.1 --enable-dap --enable-cxx --with-curl-config=/usr/bin/curl-config --enable-shared --disable-static make -k # there might be errors building the man-pages depending on tex-installation make check make -k install
Fimex and OpENDAP
Build
./configure --with-netcdf=/usr/local/netcdf4.1.1
Running an extraction from opendap
fimex --input.file=http://thredds.met.no/thredds/dodsC/topaz/dataset-topaz3-arc-myocean-be \ --input.type=netcdf \ --output.type=netcdf \ --output.file=test.nc \ \ --extract.selectVariables=time \ --extract.selectVariables=x \ --extract.selectVariables=y \ --extract.selectVariables=depth \ --extract.selectVariables=longitude \ --extract.selectVariables=latitude \ --extract.selectVariables=temperature \ \ --extract.reduceTime.start=2010-10-05 \ --extract.reduceTime.end=2010-10-07 \ \ --extract.reduceToBoundingBox.south 55.0 \ --extract.reduceToBoundingBox.north 80.0 \ --extract.reduceToBoundingBox.east 20.0 \ --extract.reduceToBoundingBox.west -5.0
Converting a model output from felt to NetCDF
- get an overview of times, layers and grid used in the felt-file
- group the parameters so that all parameters within an group use the same grid, times and the same layers (its possible to have a file with both sigma and pressure layers, but then all sigma-variables should have the same number of sigma layers and all pressure-variables should have the same number of pressure layers. Surface only variable, usually sigma=1000 felt variables, are layer-group of their own)
- create a felt2nc_variables.xml file for each variable group. Copy parameters from existing examples, or lookup variable and parameter names in the CF standard name documentation. If you have to generate several groups, it might be useful to split the file into axes, global attributes and variables, see i.e. damocles_felt2nc_variables.xml If you have two paramters which map to the same standard_name, i.e. make sure to give them different variable names if they are in the same group. Adjust the datatype according to your data. float will always work fine, use short if you know, that the variable even fits as 4-dimensional data into shorts. Use eventually a cdmWriterConfig.xml to process data as float and write the data as short.
- validate the felt2nc_variables.xml file, i.e. with
xmllint --xinclude --postvalid --noout ../../share/etc/felt2nc_variables.xml
- adjust the projection and area you want to extract in fimex_example.cfg (or use command line arguments to fimex)
- run
fimex -c fimex_example.cfg