Hi, I need to perform very fast squareroot (sqrt) operations on double type nukmbers. I tried this function mysqrt(a:double):double; var y,yn:double; begin yn:=a; repeat y:=yn; yn:=(y*y+a)/(2*y); until abs(yn-y) < 10e-16; mysqrt:=yn; end; but it is quite slow (FPC uses Heron iterations) which is 10 times faster than this code but I need even faster sqrt routin. Any ideas for optimizing the function written above would be appreciated. Pianoman ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <fpc-pascal@lists.freepascal.org> Sent: Saturday, March 11, 2006 12:00 PM Subject: fpc-pascal Digest, Vol 19, Issue 17
> Send fpc-pascal mailing list submissions to > fpc-pascal@lists.freepascal.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://lists.freepascal.org/mailman/listinfo/fpc-pascal > or, via email, send a message with subject or body 'help' to > [EMAIL PROTECTED] > > You can reach the person managing the list at > [EMAIL PROTECTED] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of fpc-pascal digest..." > > > Today's Topics: > > 1. problem setting up serial port (Marc Santhoff) > 2. Re: problem setting up serial port (Sebastian G?nther) > 3. Re: problem setting up serial port (Michael Van Canneyt) > 4. Re: problem setting up serial port (Marc Santhoff) > 5. Re: problem setting up serial port (Marc Santhoff) > 6. makeskel --update (Vincent Snijders) > 7. Re: makeskel --update (Michael Van Canneyt) > 8. Re: problem setting up serial port (Marc Santhoff) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 10 Mar 2006 15:51:46 +0100 > From: Marc Santhoff <[EMAIL PROTECTED]> > Subject: [fpc-pascal] problem setting up serial port > To: FPC-Pascal users discussions <fpc-pascal@lists.freepascal.org> > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain > > Hi, > > I'm trying to use a serial port at 1200baud, 7N2 with this code > sequence: > > <snip> > fCom := fpOpen('/dev/cuaa0', O_RDWR OR O_NOCTTY );//OR O_NONBLOCK); > if (fCom < 0) then begin > writeln(stderr, 'Couldn''t open serial port.'); > halt(1); > end; > > r := 0; > fillchar(tios, sizeof(tios), #0); > > cfsetispeed(tios, B1200); > cfsetospeed(tios, B1200); > > tios.c_cflag := CREAD or CLOCAL or CS7 or CSTOPB; > tios.c_oflag := 0; > tios.c_iflag := IGNBRK OR IGNPAR; > tios.c_lflag := 0; > r := tcsetattr(fCom, TCSANOW, tios); > if (r = -1) then begin > writeln(stderr, 'tcsetattr failed!'); > fpClose(fCom); > halt(1); > end; > </snip> > > and all I get when running it is: 'tcsetattr failed!'. The rights are > okay and running as root does make no difference. The hardware is > working, connections are checked okay ... another program doing mostly > the same is working as it should. > > Maybe I have looked at it for too long, where is the problem? > > TIA, > Marc > > > > ------------------------------ > > Message: 2 > Date: Fri, 10 Mar 2006 16:46:06 +0100 > From: Sebastian G?nther <[EMAIL PROTECTED]> > Subject: Re: [fpc-pascal] problem setting up serial port > To: FPC-Pascal users discussions <fpc-pascal@lists.freepascal.org> > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-15; format=flowed > > Marc Santhoff schrieb: > > > > Maybe I have looked at it for too long, where is the problem? > > just by the way, there is a unit called 'serial' in Free Pascal. Perhaps > you might want to use this one, or at least have a look at the source > code... > > > Regards, > Sebastian > > ------------------------------ > > Message: 3 > Date: Fri, 10 Mar 2006 17:06:37 +0100 (Romance Standard Time) > From: Michael Van Canneyt <[EMAIL PROTECTED]> > Subject: Re: [fpc-pascal] problem setting up serial port > To: FPC-Pascal users discussions <fpc-pascal@lists.freepascal.org> > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset="iso-8859-1" > > > > On Fri, 10 Mar 2006, Sebastian Günther wrote: > > > Marc Santhoff schrieb: > >> > >> Maybe I have looked at it for too long, where is the problem? > > > > just by the way, there is a unit called 'serial' in Free Pascal. Perhaps you > > might want to use this one, or at least have a look at the source code... > > Better yet, the german Magazine Toolbox distributes a unit by Rainer > Reush, with a 'TSerial' component. > AFAIK: Cross-platform and cross-delphi-lazarus... > > Michael. > > ------------------------------ > > Message: 4 > Date: Fri, 10 Mar 2006 17:11:32 +0100 > From: Marc Santhoff <[EMAIL PROTECTED]> > Subject: Re: [fpc-pascal] problem setting up serial port > To: fpc-pascal@lists.freepascal.org > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-15 > > Am Freitag, den 10.03.2006, 16:46 +0100 schrieb Sebastian Günther: > > Marc Santhoff schrieb: > > > > > > Maybe I have looked at it for too long, where is the problem? > > > > just by the way, there is a unit called 'serial' in Free Pascal. Perhaps > > you might want to use this one, or at least have a look at the source > > code... > > Yes, I know and used it at first, but since it does not give result > codes back I had to rip it up to create a test program for detecting why > it doesn't work. > > Thank you anyways, > Marc > > > > ------------------------------ > > Message: 5 > Date: Fri, 10 Mar 2006 21:01:46 +0100 > From: Marc Santhoff <[EMAIL PROTECTED]> > Subject: Re: [fpc-pascal] problem setting up serial port > To: fpc-pascal@lists.freepascal.org > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-15 > > Am Freitag, den 10.03.2006, 17:06 +0100 schrieb Michael Van Canneyt: > > > > On Fri, 10 Mar 2006, Sebastian Günther wrote: > > > > > Marc Santhoff schrieb: > > >> > > >> Maybe I have looked at it for too long, where is the problem? > > > > > > just by the way, there is a unit called 'serial' in Free Pascal. Perhaps you > > > might want to use this one, or at least have a look at the source code... > > > > Better yet, the german Magazine Toolbox distributes a unit by Rainer > > Reush, with a 'TSerial' component. > > AFAIK: Cross-platform and cross-delphi-lazarus... > > Yes, but it is not open source, I'd need something under BSD or LGPL > style licence. > > And my code should work ... ;) > > Marc > > > > ------------------------------ > > Message: 6 > Date: Fri, 10 Mar 2006 22:18:24 +0100 > From: Vincent Snijders <[EMAIL PROTECTED]> > Subject: [fpc-pascal] makeskel --update > To: FPC-Pascal users discussions <fpc-pascal@lists.freepascal.org> > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Hi, > > If I use the makeskel --update parameter, what is the best way to merge > the resulting file to the existing file? > > Vincent > > ------------------------------ > > Message: 7 > Date: Fri, 10 Mar 2006 22:50:20 +0100 (Romance Standard Time) > From: Michael Van Canneyt <[EMAIL PROTECTED]> > Subject: Re: [fpc-pascal] makeskel --update > To: FPC-Pascal users discussions <fpc-pascal@lists.freepascal.org> > Message-ID: <[EMAIL PROTECTED]> > Content-Type: TEXT/PLAIN; charset=US-ASCII > > > > On Fri, 10 Mar 2006, Vincent Snijders wrote: > > > Hi, > > > > If I use the makeskel --update parameter, what is the best way to merge > > the resulting file to the existing file? > > Copy and paste. > > Michael. > > ------------------------------ > > Message: 8 > Date: Sat, 11 Mar 2006 00:51:52 +0100 > From: Marc Santhoff <[EMAIL PROTECTED]> > Subject: Re: [fpc-pascal] problem setting up serial port > To: fpc-pascal@lists.freepascal.org > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain > > Hi again, > > from trying and decoding error messages I know the call to tcsetattr > fails with an invalid input. The problem is caused by trying to set the > field termios.c_ospeed, if left out the call is successfull. So I went > the way trough the sources and have found something. > > On FreeBSD 4.11 termios is defined like this: > > /usr/include/termios.h -> sys/termios.h > > struct termios { > tcflag_t c_iflag; /* input flags */ > tcflag_t c_oflag; /* output flags */ > tcflag_t c_cflag; /* control flags */ > tcflag_t c_lflag; /* local flags */ > cc_t c_cc[NCCS]; /* control chars */ > speed_t c_ispeed; /* input speed */ > speed_t c_ospeed; /* output speed */ > }; > > > The fpc source file "" defines it as: > > <fpc-2.0.2>/share/src/fpc-2.0.2/rtl/freebsd/termios.inc > > type > Termios = packed record > c_iflag, > c_oflag, > c_cflag, > c_lflag : longint; > c_line : char; > c_cc : array[0..NCCS-1] of byte; > {$IFDEF BSD} > c_ispeed, > c_ospeed : longint; > {$endif} > end; > TTermios=Termios; > > Note the line in pascal saying "c_line: char" which is missing in the > systems declaration. This is an error, insn't it? > > Marc > > > > ------------------------------ > > _______________________________________________ > fpc-pascal maillist - fpc-pascal@lists.freepascal.org > http://lists.freepascal.org/mailman/listinfo/fpc-pascal > > End of fpc-pascal Digest, Vol 19, Issue 17 > ****************************************** > > > __________ Informacia od NOD32 1.1438 (20060310) __________ > > Tato sprava bola preverena antivirusovym systemom NOD32. > http://www.eset.sk > > _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
