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Re[2]: Sample SQR Code - Sorting Arrays
- Subject: Re[2]: Sample SQR Code - Sorting Arrays
- From: Richard Mitchell <richard.mitchell@GSA.GOV>
- Date: Tue, 6 Oct 1998 12:17:00 -0400
Tony,
In response to your post below:
1) We are all busy - that's why they pay us. If you want to flame a
member, please post privately. We read this list because we need help
or want to share ideas .
2) I for 1 am guilty of flaming innocent people as well. It is we who
owe them the apology. It is they who feel attacked. I will give you
the benefit of the doubt (as I hope others on this list have done for
me) and let this pass as one *very* bad day.
3) As I have said to others on the list, I believe that the flow of
'utilities' is a great thing. I always intend to write them but never
get around to it. For my 2 cents, please share what you will.
I hope you have a better day,
Rick
______________________________ Reply Separator _________________________________
Subject: Re: Sample SQR Code - Sorting Arrays
Author: "tony delia" <tdelia@erols.com> at internet
Date: 10/6/98 1:04 PM
GOPAL,
Thankyou for your negative response. I am new to the group and
thought I'd share something with people new to SQR. For an SQR Wizard
such as yourself I'm sure there is nothing new or difficult about a
simple sort algorithm - but this is not GOPAL's group! It is a resource
primarily for new SQR programmers. AND I included the Assembler source
because it is "COMMENTED" and has a description of the process - I KNOW
IBM Mainframe Assembler (370) has absolutely nothing to do with SQRW!!!
I'm busy and didn't want to re-type the description - sorry! AND... I
fully understand there are times to use various sort methods
(Quicksort, Array Sort, Temporary Tables). This illustrates the method
when an array SORT is required - I'm sure everyone already knows the
other methods! And as far as your fix goes ... YOU BROKE IT BY ADDING
'<=' #ARRmax. I don't set #SORTptr to #ARRmax - EVER!!! When I'm
finished comparing element #ARRmax - 1 to #SCANptr (#ARRmax) I'm DONE!!!
With your "FIX" all you've done is set an extra gyration in the process!
Did you read the comments in the Assembler Version??? That's why I put
them there! Not to be overly sensitive but an apology is in order - My
code always works correctly. Look closer next time. I've had to come in
to work PLENTY of times at 3:00am to fix mistakes due to programmers who
"think" they know what they're doing! I APOLOGIZE TO THE GROUP BUT I
FEEL I'VE BEEN ATTACKED!!! I'll stop posting if this is the response I
get! Have a great day.
Tony DeLia
Gopal Nandakumar wrote:
>
> Hello,
>
> The sort method you used is very commonly used method and nothing new
or
> difficult to code. The following changes have to be made in your code in
> order to make to work correctly:
>
> >begin-procedure Sort-Array
> >
> >let #ARRmax = #ARRctr
> >let #SORTptr = 0
> >
> >while #SORTptr <= #ARRmax
> >
> > let #SCANptr = #SORTptr + 1
> >
> > get $SORTrec $SORTkey $SORTsec -
> > from ARRdat (#SORTptr) ARRrec ARRkey ARRsec
> >
> > while #SCANptr <= #ARRmax
>
> The while statements should have a condition of "<=".
>
> I do not understand the rationale in using assembler code in SQRW.
One
> of the main selling point for SQR is its independence of Database and
> Platform. Once we start using assembler code then we loose the
> independence. If we want to use assembler code we may be better of
> writing programs in assember completely instead of using SQRW.
>
> It is also very hard to say which SORT routine is best to use. Almo
st
> in every interface we write in SQRW, a sort routine is used. We use the
> follwoing rule of thumb:
>
> 1. If the array size is 300 or less use Quick Sort routine
> 2. If the array size is 301 - 5000 use Bubble Sort
> 3. If the array size if over 5000 use Temporary Tables.
>
> Thanks.
>
> Gopal.
> TCS INC.
> (210) 491 0046
>
> At 01:09 PM 10/2/98 -0400, you wrote:
> >Hello...
> >
> >Since there seems to be some interest in my SQR Tools Site I thought I'd
> >post a small sample. Here is some "snippets" of an Array Sorting
> >Algorithm.
> >I've also included my Assembler Version (Snippets) because I've included
> >comments and a brief narrative of the sorting process within the
> >program.
> >Also, maybe there are some old timers out there learning SQR!
> >The SQR Example sorts an array with a primary key (ARRkey), a secondary
> >key (ARRsec) and has the data stored in ARRrec (I used 1 field for
> >illustrative purposes). SORTptr is the main pointer- SCANptr is the
> >pointer for comparison. Hope nobody minds me posting to the site.
> >
> >
> > -Tony DeLia
> >
> >
> >
> >!**********************************************************************
> >!* *
> >!* MODULE: SORT EXAMPLE. *
> >!* AUTHOR: TONY DELIA. *
> >!* DATE: 10/02/1998. *
> >!* SYSTEM: TD SQR UTILITY SERIES. *
> >!* DESC: SORTING ARRAYS. *
> >!* *
> >!**********************************************************************
> >
> >..
> >..
> >do Define-Array
> >do Load-Array
> >do Sort-Array
> >..
> >..
> >
> >!**********************************************************************
> >!* Define Array *
> >!**********************************************************************
> >
> >begin-procedure Define-Array
> >
> >create-array name=ARRdat size=2000 field=ARRrec:char -
> > field=ARRkey:char -
> > field=ARRsec:char
> >
> >let #ARRmax = 2000
> >let #ARRctr = 0
> >
> >end-procedure
> >
> >!**********************************************************************
> >!* Load Array *
> >!**********************************************************************
> >
> >begin-procedure Load-Array
> >
> >let #ARRctr = 0
> >
> >while 1 = 1
> >
> > read #mmc-i-no into $rec:200
> >
> > if #end-file = 1
> > break
> > end-if
> > .
> > .
> > put $rec $skey $ssec into ARRdat (#ARRctr) ARRrec ARRkey ARRsec
> >
> > let #ARRctr = #ARRctr + 1
> >
> >end-while
> >
> >end-procedure
> >
> >!**********************************************************************
> >!* Sort Array *
> >!**********************************************************************
> >
> >begin-procedure Sort-Array
> >
> >let #ARRmax = #ARRctr
> >let #SORTptr = 0
> >
> >while #SORTptr < #ARRmax
> >
> > let #SCANptr = #SORTptr + 1
> >
> > get $SORTrec $SORTkey $SORTsec -
> > from ARRdat (#SORTptr) ARRrec ARRkey ARRsec
> >
> > while #SCANptr < #ARRmax
> >
> > get $SCANrec $SCANkey $SCANsec -
> > from ARRdat (#SCANptr) ARRrec ARRkey ARRsec
> >
> > if ($SORTkey > $SCANkey)
> > or ($SORTkey = $SCANkey
> > and $SORTsec > $SCANsec)
> >
> > put $SORTrec $SORTkey $SORTsec -
> > into ARRdat (#SCANptr) ARRrec ARRkey ARRsec
> >
> > put $SCANrec $SCANkey $SCANsec -
> > into ARRdat (#SORTptr) ARRrec ARRkey ARRsec
> >
> > let $SORTrec = $SCANrec
> > let $SORTkey = $SCANkey
> > let $SORTsec = $SCANsec
> >
> > end-if
> >
> > let #SCANptr = #SCANptr + 1
> >
> > end-while
> >
> > let #SORTptr = #SORTptr + 1
> >
> >end-while
> >
> >end-procedure
> >
> >!**********************************************************************
> >
> >Here's the Assembler Version (see comments for description of the
> >above process).
> >
> > TITLE 'TDSRT - ASSEMBLER SORT TABLE // TONY DELIA'
> >***********************************************************************
> >* *
> >* MODULE: TDSRT. *
> >* AUTHOR: TONY DELIA. *
> >* DATE: 06/28/90. *
> >* DESC: SORT TABLE OF ELEMENTS. *
> >* *
> >***********************************************************************
> > .
> > .
> >***********************************************************************
> >* SORT TABLE *
> >***********************************************************************
> > DC F'0' RETURN ADDRESS SAVE AREA
> >SORT EQU *
> > ST 6,*-4 SAVE RETURN ADDRESS
> >*
> > LH 5,SCTR LOAD ENTRY COUNT
> > CH 5,=H'1' ONLY 1 ENTRY ???
> > BE SORTX YES - EXIT SORT ROUTINE
> >*
> > BCTR 5,0 DECREMENT ENTRY COUNT BY 1
> > MH 5,=Y(SLEN) MULTIPLY BY ENTRY LENGTH
> > LA 5,STABLE(5) POINT TO LAST ENTRY
> > ST 5,SLAST SAVE LAST ENTRY ADDRESS
> >*
> > LA 4,STABLE INIT LO PTR - 1ST ENTRY
> > LA 5,SLEN(,4) INIT HI PTR - 2ND ENTRY
> >SORTIT EQU *
> > CLC 0(SLEN,4),0(5) IS LO ENTRY > HI ENTRY ??
> > BNH BUMPHI NO - BUMP HI PTR
> > XC 0(SLEN,4),0(5) YES - ISOLATE UNIQUE BITS
> > XC 0(SLEN,5),0(4) REPLACE LO WITH HI ENTRY
> > XC 0(SLEN,4),0(5) REPLACE HI WITH LO ENTRY
> >BUMPHI EQU *
> > LA 5,SLEN(,5) BUMP HI POINTER
> > C 5,SLAST HI POINTER PAST LIMIT ??
> > BNH SORTIT NO - COMPARE AGAIN
> >BUMPLO EQU *
> > LA 4,SLEN(,4) YES - BUMP LO POINTER
> > LA 5,SLEN(,4) RESET HI PTR = LO + 1
> > C 4,SLAST LO POINTER PAST LIMIT ??
> > BL SORTIT NO - KEEP SORTING
> >SORTX EQU *
> > L 6,SORT-4 RESTORE LINK REGISTER
> > BR 6 BRANCH ON LINK REGISTER
> >***********************************************************************
> >* *
> >* BUBBLE SORT LOGIC: (LOW VALUES RISE LIKE BUBBLES TO TOP). *
> >* *
> >* INITIALLY, LO PTR (4) POINTS TO ENTRY 1 AND HI PTR (5) AT 2. *
> >* LO PTR WILL REMAIN THE SAME UNTIL HI PTR REACHES THE END OF *
> >* TABLE. EACH TIME HI PTR MOVES ALONG A COMPARE IS MADE WITH *
> >* LO PTR AND ELEMENTS MAY BE SWAPPED. THIS FORCES THE LOWEST *
> >* VALUE TO THE BEGINNING OF THE TABLE. THEN LO PTR IS BUMPED *
> >* TO THE NEXT ENTRY AND HI PTR IS RESET TO LO PTR + 1 ENTRY. *
> >* PROCESS IS THEN REPEATED FORCING THE NEXT LO VALUE TO 2ND *
> >* TABLE POSITION. THIS WILL REPEAT ITSELF UNTIL LO PTR HAS *
> >* REACHED THE LAST TABLE POSITION. NOTE THAT EACH TIME LO PTR *
> >* IS BUMPED, THE PRECEDING ELEMENTS ARE IN SORTED ORDER AND *
> >* ARE NO LONGER INCLUDED IN THE SORT PROCESS (TABLE SHRINKS). *
> >* *
> >***********************************************************************
> > EJECT
> >***********************************************************************
> >* TABLE *
> >***********************************************************************
> >SLEN EQU 2 TABLE ENTRY LENGTH
> >SLAST DC F'0' LAST ENTRY ADDRESS
> >SCTR DC H'0' NUMBER OF TABLE ENTRIES
> >STABLE DC 100CL2' ' 2-DIGIT TABLE
> >STABLEX DC X'FF' END-OF-TABLE MARKER
> >***********************************************************************
> > END TDSRT
> >
> >
> >
> >--
> >Tony DeLia
> >AnswerThink Consulting Group
> >PeopleSoft Solutions Practice - Delphi Partners
> >tdelia@erols.com
> >
--
Tony DeLia
AnswerThink Consulting Group
PeopleSoft Solutions Practice - Delphi Partners
tdelia@erols.com