[fdo-internals] New RFC posted

Tue Aug 21 15:40:37 EDT 2007

Hi Jason

Sorry for the late response on this as I did not get to do it during my vacation.

The issues with the geometric functions like area and length are with coordinate system/projection support. 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.

Unlike the geometric functions, the functions documented in RFC 8 are rather simple. The idea was to keep those separated from the geometric functions to ensure nothing gets overlooked and allow progress on implementing the basic functions while discussion on geometric functions goes ahead.

As for the functions MOD and REMAINDER, although the basically perform a similar kind of operation, they are defined differently. The distinction is with the sign of the return value: in case of the function MOD, it corresponds to the sign of the divisor, in case of the function REMAINDER, it corresponds to the sign of the dividend. Usually, in number theory, the remainder (independent of the functions) is always a positive number. However, with software products this might not be the case.

As for the math operators with date functions, there was no intent to support such operators other than on months. 

As for the code page question, I am not sure where you are heading here. 

Thanks

  Thomas

From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Thomas Knoell
Sent: Friday, August 03, 2007 6:39 PM
To: fdo-internals at lists.osgeo.org
Subject: Re: [fdo-internals] New RFC posted

Hi Jason

I will see what I can do. I am just leaving for my vacation and have to get back to you on this next week (although being on vacation, I'll still try to answer mails). I hope it can wait until then.

Thanks

  Thomas

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----- Original Message -----
From: fdo-internals-bounces at lists.osgeo.org <fdo-internals-bounces at lists.osgeo.org>
To: FDO Internals Mail List <fdo-internals at lists.osgeo.org>
Sent: Fri Aug 03 18:06:32 2007
Subject: RE: [fdo-internals] New RFC posted

Could you maybe outline those issues? 

It would be helpful if we could all have an idea of what is coming up and see how it fits together, rather than being fed RFCs / problems piecemeal.

I was able to read the PDF version, btw, and it answers most of my questions.  I still don't know what the difference between Mod and Remainder is though :)

A couple functions raise questions for me

- the date functions have month math operators, but none for other units?
- is there a common way of specifying code pages that all providers should understand?  I don't know much about this area.

Jason

  _____ 

From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Thomas Knoell
Sent: Friday, August 03, 2007 14:53
To: fdo-internals at lists.osgeo.org
Subject: Re: [fdo-internals] New RFC posted

For the geometry functions, there are different issues to address which we thought is better suited to be outlined separately.

Thanks

  Thomas

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Sent from my BlackBerry Wireless Handheld (www.BlackBerry.net)

----- Original Message -----
From: fdo-internals-bounces at lists.osgeo.org <fdo-internals-bounces at lists.osgeo.org>
To: FDO Internals Mail List <fdo-internals at lists.osgeo.org>
Sent: Fri Aug 03 17:45:04 2007
Subject: RE: [fdo-internals] New RFC posted

Is there any specific reason for that ?

 Haris

From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Thomas Knoell
Sent: Friday, August 03, 2007 11:40 PM
To: fdo-internals at lists.osgeo.org
Subject: Re: [fdo-internals] New RFC posted

Spatial functions will be handled separately.

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Sent from my BlackBerry Wireless Handheld (www.BlackBerry.net)

----- Original Message -----
From: fdo-internals-bounces at lists.osgeo.org <fdo-internals-bounces at lists.osgeo.org>
To: FDO Internals Mail List <fdo-internals at lists.osgeo.org>
Sent: Fri Aug 03 17:35:42 2007
Subject: RE: [fdo-internals] New RFC posted

I’ve noticed there is no any Spatial Functions. What is a reason for that?

Thank you,

Haris

From: fdo-internals-bounces at lists.osgeo.org [mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Thomas Knoell
Sent: Friday, August 03, 2007 9:35 PM
To: FDO Internals Mail List
Subject: [fdo-internals] New RFC posted

Hi,

A new RFC (http://trac.osgeo.org/fdo/wiki/FDORfc8) has been posted. The RFC addresses the enhancement of the FDO well known (expression) function list to include additional, commonly used functions.

Please review the RFC. Any comments/suggestions and questions are welcome. All feedback is expected by the end-of-day August 10th 2007. If no changes are required it is my intent to motion that a vote for the acceptance of the RFC be made and subsequently voted on by the PSC.

Thanks

  Thomas

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