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tools:interpolation [2015/05/26 13:27] (current)
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 +
 +
 +
 +==== Objective ====
 +
 +
 +
 +==== Description ====
 +
 +
 +interp.bash is a script encapsulating the interpolator and the preparation of its namelist. It
 +is able to interpolate from and to 11 different horizontal grids
 +(ORCA1t_v2.2/​ORCA1t_v3.2/​ORCA025t_v3.2/​ERA40/​ERAint/​EcEarth2/​EcEarth3/​HadISST/​NCEP/​NOAAv3b/​NSIDC)
 +and with 4 different interpolation (conservative,​ bilinear, bicubic, distance-weighted) methods.
 +Usually, the conservative method is used for surface fluxes or tas/tos which ensures that their 
 +global mean is conserved through the interpolation. If you are interested in extremes, it is 
 +better to use the bicubic method which avoid smoothing the extrema. interp.bash can interpolate files
 +with dimentions (lon,lat) or (lon,​lat,​time). The input file is written also in the output file so that you can
 +check whether it is correctly read by the interpolator. All the attributes of your variable and history ​
 +of your input file will be copied to the output file.
 +interp.bash compensates for the  unability of cdo to 
 +interpolate from and to irregular grids. The interp.bash script should be used to interpolate from and to 
 +the various ORCA grid which we manipulates at CFU.
 +For any other interpolation,​ you can use cdo. Running interp.bash without argument will 
 +print an help. For any questions about the script and interpolator itself, please feel free to ask 
 +Virginie. If you want to include a new ORCA grid, Isabel can also teach you how to prepare your weights.
 +
 +If the default options chosen by interp.bash do not fit your needs, you'll need to know a bit more 
 +about the interpolator itself. The interpolator is named scrip_use and it is stored at 
 +https://​dev.cfu.local/​cfu_tools.git interpolation folder. It uses weights computed with SCRIP, a free software that you
 +can download. scrip_use works with a namelist named scrip_use_in. An example can be 
 +found in https://​dev.cfu.local/​cfu_tools.git interpolation folder. In case your input field appears upside down in the output file, 
 +put the invertlat option to TRUE in the namelist. A second interpolator,​ named scrip_use_extrap,​ is also 
 +in the directory. The namelist is exactly the same as scrip_use. It also works both on (lon,lat)
 +and (lon,​lat,​time) fields. The difference is that after the interpolation (bicubic/​bilinear/​conservative/​neighbour)
 +scrip_use_extrap performs an extrapolation to fill the missing value by the neighbour method. This can be useful
 +if for example your input and output grid do not have the same land-sea mask. scrip_use will put missing value in
 +the interpolated field where there is no data in the input field to interpolate while scrip_use_extrap will fill in these
 +blanks by an extrapolation. So the interpolator to use depends on what you want to do with your interpolated field.
 +
 +
 +=== List of functions ===
 +
 +
 +
 +==== Requirements ====
 +
 +
 +
 +==== Use ====
 +
 +
 +
 +==== Repository ====
 +
 +
 +The link to the GIT repository is https://​dev.cfu.local/​cfu_tools.git
 +
 +
 +==== Contact ====
 +
 +
 +The coordinator of this project is Domingo Manubens Gil <​domingo.manubens@ic3.cat>​
 +
 +Virginie Guemas <​virginie.guemas@ic3.cat>​
 +
 +As a new user, please register to this mailing list: http://​cfutools.ic3.cat/​mailman/​listinfo/​cfutools
 +You'll then have access to the history of all the emails sent to the users and presenting the
 +functions and their available options.
 +
 +
 +==== Development ====
 +
 +
 +
 +=== Package structure ===
 +
 +
 +
 +=== How to develop ===
 +
 +
 +Download the repository folder to your computer ( git clone https://​dev.cfu.local/​cfu_tools.git <​local_folder>​ ) and check-out to the branch you want to develop in.
 +
 +
 +=== Steps to add a new function to a package ===
 +
 +
 +  *  Put the code of the function in a file.
 +  *  Make sure the code of the function follows the style rules (information below header, history, ...).
 +  *  Fill in the file with the function documentation.
 +
 +
 +==== Style Guide ====
 +
 +You can check the style guide for the Interpolation package [[tools:​style_guides:​bash|here]]
  
tools/interpolation.txt ยท Last modified: 2015/05/26 13:27 (external edit)