Changes between Version 2 and Version 3 of FDORfc8


Ignore:
Timestamp:
Aug 23, 2007, 8:17:42 AM (17 years ago)
Author:
thomasknoell
Comment:

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  • FDORfc8

    v2 v3  
    11
    22
    3 = FDO RFC 5 -  Modify Fdo API !FdoFunctionDefinition =
     3= FDO RFC 8 -  Modify Fdo API !FdoFunctionDefinition =
    44
    55This page contains a request for comments document (RFC) for the FDO Open Source project. 
    … …  
    3030The following sections list all newly added functions only. Functions already supported (like Max, Min, Sum) are not listed.
    3131
     32'''Note''': This RFC does not address geometric functions like ''Area'' and ''Length''. This will be addressed in a separate RFC. The reason for this is that there are some issues with respect to coordinate systems/projections to be considered. It is expected that this will result in some discussion within the group. FDO includes coordinate system specification via spatial context, but FDO itself does not expose any projection capabilities nor does it specify use of coordinate system packages. Most providers do not have coordinate system packages available internally. !MapGuide for instance does all of its projection work separately, outside of FDO. So we should discuss what happens if the data is lat/long (for example).
     33 
    3234
    3335=== Aggregate Function ===
    … …  
    105107'''Round''': Returns the rounded value of a numeric expression.
    106108
    107 '''Sign''': Returns the sign of a numeric expression.
     109'''Sign''': Returns the sign of a numeric expression. The returned value is ''-1'' if the expression evaluates to a value les than 0, ''0'' if the expression evaluates to 0 and ''1'' if the expression evaluates to a value bigger than 0.
    108110
    109111'''Trunc''': Truncates a numeric or date expression.