Re: Tie Breaker in SORTA -- RPG400-L

+1 on the ease of using qsort - and the "Did you know you could do this" redbook has a very understandable example - you name a procedure that will get the information you want to use to determine order, that will have parameters to match - you return something that says hi, lo, or equal, kind of, and you're done - that procedure is called by qsort for every pair of values it wants to know the order of.

HTH
Vern

On 6/7/2014 10:02 AM, Jon Paris wrote:

But why bother Booth when qsort is available and very easy to use? Admittedly it may look "odd" the first time you use it but since every time you do it the base logic is identical it really is a short learning curve.

On 2014-06-06, at 6:52 PM, Booth Martin <booth@xxxxxxxxxxxx> wrote:

Field1 would be the sequence number I suppose, and Field2 would be what ever substring he wanted to choose out of UDFNoLists. Or, Field2 could be sequentially numbered at array-load time,. Or some other external sequencing strategy he sees as appropriate.

When one wants users to be able to sort a subfile by columns, ascending & descending , one can create a single sort field and populate that field with a data structure of the fields to be sorted, in order by preference. Its a tad cumbersome, but for load-all subfiles under 2500 records it works, and has great response times.

The sorting subfile example I have on my web site sorts by columns, but only one column at a time. I have done sequencing by the order chosen, but that gets harem-scarum for a yeoman programmer like me.

http://martinvt.com/Subfiles/SFL_Sort/sfl_sort.html

On 6/6/2014 3:52 PM, Jon Paris wrote:

What key are you going to sort on Booth?

Regardless - the only way it can be made to work with SortA is if:

a) The required keys are contiguous in the DS
b) The keys are in the correct sequence (i.e. high order followed by low order) and
c) Are both alpha since they must be redefined as alpha to meet SortAs single key requirement.

None of these conditions are in play here as far as I can see.

On 2014-06-06, at 4:19 PM, Booth Martin <booth@xxxxxxxxxxxx> wrote:

Would something like this also work?

D UDFNoListN DS Qualified
D UDFNoEntry 50 DIM(100)
D UDFNoListS 44 Overlay(UDFNoEntry:*Next)
D UDFNoAppSeq 6S 0 INZ(*hival)Overlay(UDFNoEntry:*Next)
D Field1 nn Overlay(UDFNoAppSeq)
D Field2 nn Overlay(UDFNOAppSeq *next)
D etc...

On 6/6/2014 2:58 PM, Jon Paris wrote:

When sorting (using most any facility) initial sequence is rarely guaranteed to be maintained. So whenever two records have the same key the sequence in which they appear in the final result is indeterminate.

If you want them to retain original sequence, or indeed use any secondary key, then you need to use a method that allows for multiple keys - such as the qsort API. There is an example of how to use this in the RPG Redbook "Who Knew ..." http://www.redbooks.ibm.com/redbooks/pdfs/sg245402.pdf

On 2014-06-06, at 3:10 PM, Ashwani Singh <Ashwani.Singh@xxxxxxxxxx> wrote:

Hello ,

I have code where I need to sort a DS array basis of a sequence field..

D UDFNoListN DS Qualified
D UDFNoEntry 50 DIM(100)
D UDFNoListS 44 Overlay(UDFNoEntry:*Next)
D UDFNoAppSeq 6S 0 INZ(*hival)Overlay(UDFNoEntry:*Next)

SORTA UDFNoAppSeq;

With this input
UDFNOLISTN.UDFNOLISTS(1) = 'XXFIV01 XX Rate XXFIV01 ¬A1' 050002

UDFNOLISTN.UDFNOLISTS(2) = 'XXFIV05 XxFIV05 XXFIV05 ¬A1' 050003

UDFNOLISTN.UDFNOLISTS(3) = 'XXTHI01 XXTHI01 XXTHI01 A1' 050001

UDFNOLISTN.UDFNOLISTS(4) = 'XXSEV01 XXXX Rate XXSEV01 "P1' 050002

UDFNOLISTN.UDFNOLISTS(5) = 'XXSEV02 XXSEV02 XXSEV02 "P1' 050999

Output

UDFNOLISTN.UDFNOLISTS(3) = 'XXTHI01 XXTHI01 XXTHI01 A1' 050001
UDFNOLISTN.UDFNOLISTS(4) = 'XXSEV01 XXXX Rate XXSEV01 "P1' 050002
UDFNOLISTN.UDFNOLISTS(1) = 'XXFIV01 XX Rate XXFIV01 ¬A1' 050002

I would have expected element 1 above 4 but its not ? Any particular reason...

Etc..

Thanks,
Ashwani Singh
Technical Analyst
Global Services
Fiserv
Office: + 1 – 407 – 513 - 5394
Mobile: +91-976-579-7691
Toll Free (Office): +1-811--301-9471 x4743 www.fiserv.com P Please consider the environment before printing this e-mail

--
This is the RPG programming on the IBM i (AS/400 and iSeries) (RPG400-L) mailing list
To post a message email: RPG400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/rpg400-l
or email: RPG400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/rpg400-l.

Jon Paris

www.partner400.com
www.SystemiDeveloper.com

--
Booth Martin
www.martinvt.com
(802)461-5349
Skype: booth.martin

No matter where you go, there you are. -- Buckaroo Banzai
--
This is the RPG programming on the IBM i (AS/400 and iSeries) (RPG400-L) mailing list
To post a message email: RPG400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/rpg400-l
or email: RPG400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/rpg400-l.

Jon Paris

www.partner400.com
www.SystemiDeveloper.com

--
This is the RPG programming on the IBM i (AS/400 and iSeries) (RPG400-L) mailing list
To post a message email: RPG400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/rpg400-l
or email: RPG400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/rpg400-l.

Jon Paris

www.partner400.com
www.SystemiDeveloper.com