Changes between Version 35 and Version 36 of WCSTImportGuide


Ignore:
Timestamp:
Mar 28, 2017 8:42:47 AM (4 months ago)
Author:
bphamhuu
Comment:

Remove the deprecate subset_correction faq

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  • WCSTImportGuide

    v35 v36  
    811811We now have a functional recipe. You can try the ingredients file against it and see how it works.
    812812
    813 
    814 == FAQ ==
    815 
    816 === Why is the subset_correction needed? ===
    817 
    818 The subset_correction feature is needed when there is a discrepancy between the precision of gdal (or other tools used in the creation of gml coverages) and the precision of petascope. Take for example this coordinate 0.33333333, this would be represented in gdal as 0.3333333374353 for example due to the loss of precision in floating point values. Petascope uses BigDecimal that keeps the precision up to 50 decimals.
    819 When working with arithmetic operations, the difference between the two leads to inconsistencies that cannot be detected automatically. WCST Import tries to help with that by giving the users the option of trying to ingest the coverage by adding a small number (<= offset_vector / 2) to the coordinates in order to correctly align the subsets. However this is not guaranteed to work, for example if your extent is close to the next geopixel by less than 1/2 of the offset vector. In this cases it is left to the user to deal with the incosistency (e.g. by manually creating the coverage)