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Last edited [[Timestamp]]

[[BR]]

'''Author''' : Clement BRICAUD

'''ticket''' : #650

'''Branch''' : [https://forge.ipsl.jussieu.fr/nemo/browser/branches/DEV_r1784_3DF] 
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=== Description ===

On-the-fly interpolation for 3D files.
It will replace time-interpolation for intial state in dtatem and dtasal.
In fldread, fnow has now a third dimension ( vertical ) and fdta a forth dimension ( vertical too).
In consequence, all routines using fldread will be modified, when fdta and fnow are allocated ; we decided to not allocate fdta when time-interpolation is not used.
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=== Testing ===
Testing could consider (where appropriate) other configurations in addition to NVTK].

||NVTK Tested||!'''YES!'''||
||Other model configurations||!'''YES!'''||
||Processor configurations tested||[ 2*1 , 1*2 , 2*2 ]||
||If adding new functionality please confirm that the [[BR]]New code doesn't change results when it is switched off [[BR]]and !''works!'' when switched on||!'''NO!'''||

In dtatem and dtasal, time-interpolation formula is  : 
     zxy = FLOAT( nday + 15 - 30 * i15 ) / 30.
      t_dta(:,:,:) = (1.-zxy) * temdta(:,:,:,1) + zxy * temdta(:,:,:,2)
Here, lenght of month is hard-coded: 30 days.

Now, with fldread, computing is exact.


=== Bit Comparability ===
||Does this change preserve answers in your tested standard configurations (to the last bit) ?||!'''YES/NO !'''||
||Does this change bit compare across various processor configurations. (1xM, Nx1 and MxN are recommended)||!'''YES/NO!'''||
||Is this change expected to preserve answers in all possible model configurations?||!'''YES/NO!'''||
||Is this change expected to preserve all diagnostics? [[BR]]!,,!''Preserving answers in model runs does not necessarily imply preserved diagnostics. !''||!'''YES/NO!'''||

If you answered !'''NO!''' to any of the above, please provide further details:

 * Which routine(s) are causing the difference?
 * Why the changes are not protected by a logical switch or new section-version
 * What is needed to achieve regression with the previous model release (e.g. a regression branch, hand-edits etc). If this is not possible, explain why not.
 * What do you expect to see occur in the test harness jobs?
 * Which diagnostics have you altered and why have they changed?Please add details here........

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=== System Changes ===
||Does your change alter namelists?||!'''YES/NO !'''||
||Does your change require a change in compiler options?||!'''YES/NO !'''||

If any of these apply, please document the changes required here.......

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=== Resources ===
!''Please !''summarize!'' any changes in runtime or memory use caused by this change......!''

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=== IPR issues ===
||Has the code been wholly (100%) produced by NEMO developers staff working exclusively on NEMO?||!'''YES/ NO !'''||

If No:

 * Identify the collaboration agreement details
 * Ensure the code routine header is in accordance with the agreement, (Copyright/Redistribution etc).Add further details here if required..........