PRDESENV%ORION.CPQD.ANSP.BR@uga.cc.uga.edu (11/26/90)
Hey,
Does anybody know how can I build a SET with Real (or double)
elements in Turbo Pascal? I Only need a SET with 15 real numbers.
Once SET requires subranges with no more than 256 itens I can not
make a set of word (my real numbers have only one place after
the decimal point, so I could multiply by 10, solving the problem, but
the range from the first to the last overcome 256).
I've tried to make a TYPE with these numbers but Turbo gives an
error saying "Error 2: Identifier expected" .
Any help has value. Thanks.
Claudiodmurdoch@watstat.waterloo.edu (Duncan Murdoch) (11/26/90)
In article <25092@adm.brl.mil> PRDESENV%ORION.CPQD.ANSP.BR@uga.cc.uga.edu writes: >Hey, > > Does anybody know how can I build a SET with Real (or double) >elements in Turbo Pascal? I Only need a SET with 15 real numbers. If you have version 5.5 or 6.0, you could get Object Professional from Turbopower Software. It includes objects that can handle integer type sets with more than 256 elements, and a general purpose set for strings, that could easily be made to hold floating point values. There's also a huge number of other routines, mostly dealing with user interface objects. I don't have their number handy, but they advertise regularly in PC programming magazines. You can also contact them by email; my alias line for them is alias turbopower 76004.2611@compuserve.com Duncan Murdoch
zhou@brazil.psych.purdue.edu (Albert Zhou) (11/27/90)
In article <25092@adm.brl.mil> PRDESENV%ORION.CPQD.ANSP.BR@uga.cc.uga.edu writes: >Hey, > > Does anybody know how can I build a SET with Real (or double) >elements in Turbo Pascal? I Only need a SET with 15 real numbers. There is no directly way of doing it in TP. But you can map these 15 reals to 0..14 and subsequently define a set of byte [0..14]. > > Once SET requires subranges with no more than 256 itens I can not >make a set of word (my real numbers have only one place after >the decimal point, so I could multiply by 10, solving the problem, but >the range from the first to the last overcome 256). It looks like you need to do certain non-linear transform so that you can map no more than 255 reals or integers into a set of byte (Multiplying by 10 is a kind of transform or mapping if you haven't aware, very simple linear transform though). > > I've tried to make a TYPE with these numbers but Turbo gives an >error saying "Error 2: Identifier expected" . As I remember, you can make subrange out of BYTE, CHAR, INTEGER and WORD (They are all ordinal). But you cannot make subrange out of REAL.
CDCKAB%EMUVM1.BITNET@cunyvm.cuny.edu ( Karl Brendel) (11/27/90)
In article <9011260748.aa11950@VIM.BRL.MIL> PRDESENV%ORION.CPQD.ANSP.BR@uga.cc.uga.edu ( Claudio ) writes: >Does anybody know how can I build a SET with Real (or double) >elements in Turbo Pascal? I Only need a SET with 15 real numbers. > >Once SET requires subranges with no more than 256 itens I can not >make a set of word (my real numbers have only one place after the >decimal point, so I could multiply by 10, solving the problem, but >the range from the first to the last overcome 256). [deleted to end] In article <9011260916.aa08727@VGR.BRL.MIL> ZCCBJSB%EB0UB011.BITNET@cunyvm.cuny.edu ( Josep Sau B. ) writes: >If those real values are variable, forget it, you can't use the set >structure. > >If those real values are constant, you may do thru with this trick: > >Declare a const array of real, and use the ordinal index type to >build up the set to work with. [deleted to end] I just wanted to point out that Josep Sau B.'s method may be more general than he admits: You should be able to declare a _variable_ array [1..max] of reals together with the value of the highest index in use. Then add reals to the array as required, starting with element 1. If you delete an element from the set, compact the array and Dec the value of the high index. Example: const maxIndex = 255; type RealSetArray = array[1..maxIndex]of real; var RealSet : RealSetArray; i,hiIndex : byte; procedure InitRealSetArray(var index : byte); begin index := 0; end; function RealInSet (r : real; var rsa : RealSetArray; var i : byte; hiIndex : byte) : Boolean; {Obviously for a large set you'd use a more sophisticated searching routine than you see here--but this is about sets, not about searching. <g>} var ii : byte; begin for ii := 1 to hiIndex do if r = rsa[ii] then begin RealInSet := True; i := ii; Exit; end; RealInSet := False; end; function AddRealToSet (r : real; var rsa : RealSetArray; var index : Byte) : Boolean; var i : byte; begin AddRealToSet := True; if not RealInSet(r,rsa,i,index) then begin if index = maxIndex then AddRealToSet := False else begin Inc(index); rsa[index] := r; end; end; end; procedure RemoveRealFromSet (r : real; var rsa : RealSetArray; var index : Byte); var i : byte; begin if RealInSet(r,rsa,i,index) then begin rsa[i] := rsa[index]; Dec(index); end; end; begin InitRealSetArray(hiIndex); if not AddRealToSet(3.1415,RealSet,hiIndex) then Halt(1); if not AddRealToSet(2.7183,RealSet,hiIndex) then Halt(1); if not AddRealToSet(-1.5708,RealSet,hiIndex) then Halt(1); WriteLn('2.5 is in the set: ',RealInSet(2.5,RealSet,i,hiIndex)); WriteLn('Pi is in the set: ',RealInSet(3.1415,RealSet,i,hiIndex)); RemoveRealFromSet(3.1415,RealSet,hiIndex); if not AddRealToSet(2.5,RealSet,hiIndex) then Halt(1); WriteLn('Added 2.5, deleted 3.1415'); WriteLn('2.5 is in the set: ',RealInSet(2.5,RealSet,i,hiIndex)); WriteLn('Pi is in the set: ',RealInSet(3.1415,RealSet,i,hiIndex)); end. Caveat about RealInSet: Anything which relies on comparing "real" numbers for "exact equality" can prove flakey. You may want to Trunc or Round your reals in some manner which leads to reliable comparisons. +-------------------------------------------------------------------------+ | Karl Brendel Centers for Disease Control | | Internet: CDCKAB@EMUVM1.BITNET Epidemiology Program Office | | Bitnet: CDCKAB@EMUVM1 Atlanta, GA, USA | | ILink/RIME: KARL BRENDEL phone 404/639-2709 | | CIS : 73307,3101 fts 236-2709 | | GEnie: K.BRENDEL Home of Epi Info 5.0 | +-------------------------------------------------------------------------+
ANNEKE%HUTRUU54.BITNET@uga.cc.uga.edu ( Anneke Sicherer-Roetman) (11/30/90)
As far as I know a set always consists of types that exist in discrete values, that is all simple types EXCEPT real. What you want is therefore impossible. Anneke