Changes between Initial Version and Version 1 of ToolsAndUtilities/UmFileTools


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Timestamp:
29/04/13 15:30:29 (7 years ago)
Author:
ros
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  • ToolsAndUtilities/UmFileTools

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     1[[PageOutline]] 
     2 
     3= UM File Manipulation Tools = 
     4 
     5There are three prinicple file format issues to consider 
     6 
     7 * **UM format/PP format** \\ 
     8 The UM itself uses what is called UM format files which are direct access files. But some users and the UK Met Office convert the UM output files to PP format files which are sequential access. So many files from the UK Met Office and the BADC are PP format files not UM format files. 
     9 
     10 * **64 bit/32 bit** \\ 
     11 On the national HPC computers NCAS has installed the UM using 64 bit precision so output files are 64 bit but the UK Met Office utilities and many locally developed tools and utilities expect 32 bit precision files. 
     12 
     13 * **little endian/big endian** \\ 
     14 This is just the order in which bytes are stored on the computer. HECToR and Polaris are little-endian. 
     15 
     16The following tools are available on HECToR, the national high performance computer used by NCAS. They are stored in the directory: 
     17{{{ 
     18/work/n02/n02/hum/bin 
     19}}} 
     20which should be accessible by all NCAS HPC account holders. 
     21 
     22||ff2pp || Converts 64 bit UM format files but only fields files not ancillary or dump files to 32 bit PP format files || 
     23||uminfo || Outputs header information in a readable format for UM format file || 
     24||ppinfo || Outputs header information in a readable format for PP format files || 
     25||umpack || Removes spare headers and 'extra space' created when using well formed I/O and so reducing file sizes. This tool is called automatically when using the NCAS facilty of automatic archiving || 
     26||xconv ||A useful tool, with a user interface, that can be used to display and plot UM file contents as well as converting file formats or for transforming data || 
     27|| xancil ||A new tool that can take a netcdf file on a UM grid, either old dynamics or new dynamics, and creates a UM ancillary file||