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[mathcad] Re: 6 decimal place precision

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[mathcad] Re: 6 decimal place precision
Author: Sven Lindhardt    Posted: Sat, 26 Jul 2003 08:54:43 +0200
You can do something like this (2 decimals precision) f(x) := trunc(x*100)/100 Example f(1/3) = 0.33 Sven Lindhardt ----- Original Message ----- From: "Bill Dumke" /> To: "Mathcad Discussion List" /> Sent: Saturday, July 26, 2003 6:40 AM Subject: [mathcad] 6 decimal place precision > How do I limit Mathcad 2001i to only 6 decimal place precision? I am > trying to simulate a numerical processor doing some complex > calculations. It only has that precision. When I try to change TOL, > nothing seems to happen. > > Bill >

[mathcad] Re: 6 decimal place precision
Author: Bill Dumke    Posted: Sat, 26 Jul 2003 03:08:44 -0500
Sven, Thanks for the suggestion, but I am working with complex numbers. trunc only works for real numbers. Bill --- The Mathcad List - Discussion, Support & News Contributions: /> Hosted by: Adept Scientific http://www.adeptscience.com List Archive: http://lists.adeptscience.co.uk/ --- Would you like this to come to a different email address? --- Simply leave the mailing list (see below) and re-join by sending a blank email from the new address to: or --- If you do not want to be on the Mathcad list, simply send a blank email (no subject or message needed) to: />

[mathcad] Re: 6 decimal place precision
Author: Sven Lindhardt    Posted: Sat, 26 Jul 2003 14:05:05 +0200
> Sven, > > Thanks for the suggestion, but I am working with complex numbers. > trunc only works for real numbers. > > Bill Hi Bill, Maybe the enclosed function can be used Sven
Attachments:  ctruncate.mcd

[mathcad] Re: 6 decimal place precision
Author: Stuart Bruff    Posted: Sat, 26 Jul 2003 13:37:47 +0100
Bill Please find attached M2000 format worksheet with complex trunc. However, I don't think trunc will do the job for lsdigit level calculations. Mathcad will still calculate the truncated numbers at full 15 digit precision. The only way I can think of, off the top of my head, is to write a vector-based 6 digit calculator in Mathcad ... err, must dash, got a lawn to mow, kids to get lunch for and the wife'll kill me if I start on that :-) Stuart ----- Original Message ----- From: "Bill Dumke" /> To: "Mathcad Discussion List" /> Sent: Saturday, July 26, 2003 9:08 AM Subject: [mathcad] Re: 6 decimal place precision > Sven, > > Thanks for the suggestion, but I am working with complex numbers. > trunc only works for real numbers. > > Bill > > > --- > The Mathcad List - Discussion, Support & News > Contributions: /> > Hosted by: Adept Scientific http://www.adeptscience.com > List Archive: http://lists.adeptscience.co.uk/ > --- > Would you like this to come to a different email address? > --- > Simply leave the mailing list (see below) and re-join by > sending a blank email from the new address to: > or > --- > If you do not want to be on the Mathcad list, simply send a > blank email (no subject or message needed) to: > /> >
Attachments:  Complex Trunc 2000.mcd

[mathcad] Re: 6 decimal place precision
Author: Bill Dumke    Posted: Sun, 27 Jul 2003 19:05:12 -0500
Sven, I tried your method and thought it might work if I truncated the result of every piece of the whole function. But I found it will not work for floating point complex numbers. Any ideas? See attached file. Bill
Attachments:  ctruncate2.mcd

[mathcad] Re: 6 decimal place precision
Author: Richard Jackson    Posted: Mon, 28 Jul 2003 10:18:46 -0400
What you really need it significant digits, not decimal places. 83333333333333.33333333 to 2 decimal places is 83333333333333.33, whereas to 6 significant digits it is 83333300000000.0 The attached file contains a couple of functions to round to a specified number of significant digits. I never wrote the one to always round down, but it shouldn't be hard to adapt the existing ones if this is needed. Richard On 27 Jul 2003 at 19:05, Bill Dumke wrote: > Sven, > > I tried your method and thought it might work if I truncated the result > of every piece of the whole function. But I found it will not work for > floating point complex numbers. Any ideas? See attached file. > > Bill >
Attachments:  Significant Digits 2000.mcd

[mathcad] Re: 6 decimal place precision
Author: Jean Rosenfeld    Posted: Mon, 28 Jul 2003 16:33:00 +0100
For floating point numbers greater than 10 the proposed truncation method will not reduce the number of carried decimal places to 6, which is what I understand you want. You need first to divide |z| by factors of 10 until its less than 10, then truncate, then multiply back by the factors of 10 that you divided by. Try the attached. -------------------------------------------------------- Jean L.J. Rosenfeld Argoed Hall Bryn-y-Baal Mold Flintshire CH7 6SQ Wales, UK Tel +44 1352 750566 E-mail /> -----Original Message----- From: Bill Dumke Sent: 28 July 2003 01:05 To: Mathcad Discussion List Subject: [mathcad] Re: 6 decimal place precision Sven, I tried your method and thought it might work if I truncated the result of every piece of the whole function. But I found it will not work for floating point complex numbers. Any ideas? See attached file. Bill
Attachments:  ctruncate3.mcd

[mathcad] Re: 6 decimal place precision addendum
Author: Jean Rosenfeld    Posted: Mon, 28 Jul 2003 19:42:23 +0100
Further to my previous note with attachment to truncate to 6 decimal places. You might consider rounding to six instead. This depends on how the system you are trying to simulate handles numbers less than 10^-6. Also, for floating numbers less than 1, if the system you are trying to simulate always has numbers in the form 1.123456 x10^n, you should extend as shown under dround in the attached. There is probably a more elegant way of programming that (I had to set the trap for x = 0 or y = 0). I just want to make the point that it really depends on how the system you are simulating works: Fixed decimal point numbers to 6 decimal places, 1.123456 x 10^-7 = 0.0000001123456 carries through as 0 Floating point decimal number to 6 decimal places 1.123456 x 10^-7 is preserved, etc. Dtrunc would be analogous to dround, but I did not do it. I hope this carries things a little further..it needs checking out more thoroughly for other operands. -------------------------------------------------------- Jean L.J. Rosenfeld Argoed Hall Bryn-y-Baal Mold Flintshire CH7 6SQ Wales, UK Tel +44 1352 750566 E-mail /> -----Original Message----- From: Bill Dumke Sent: 28 July 2003 01:05 To: Mathcad Discussion List Subject: [mathcad] Re: 6 decimal place precision Sven, I tried your method and thought it might work if I truncated the result of every piece of the whole function. But I found it will not work for floating point complex numbers. Any ideas? See attached file. Bill
Attachments:  ctrunc or round.mcd

[mathcad] Re: 6 decimal place precision
Author: Sven Lindhardt    Posted: Tue, 29 Jul 2003 17:51:47 +0200
Here is another example inspired by Jean, it can handle very small numbers too, Sven ----- Original Message ----- From: "Jean Rosenfeld" /> To: "Mathcad Discussion List" /> Sent: Monday, July 28, 2003 5:33 PM Subject: [mathcad] Re: 6 decimal place precision For floating point numbers greater than 10 the proposed truncation method will not reduce the number of carried decimal places to 6, which is what I understand you want. You need first to divide |z| by factors of 10 until its less than 10, then truncate, then multiply back by the factors of 10 that you divided by. Try the attached. -------------------------------------------------------- Jean L.J. Rosenfeld Argoed Hall Bryn-y-Baal Mold Flintshire CH7 6SQ Wales, UK Tel +44 1352 750566 E-mail /> -----Original Message----- From: Bill Dumke /> Sent: 28 July 2003 01:05 To: Mathcad Discussion List Subject: [mathcad] Re: 6 decimal place precision Sven, I tried your method and thought it might work if I truncated the result of every piece of the whole function. But I found it will not work for floating point complex numbers. Any ideas? See attached file. Bill --- The Mathcad List - Discussion, Support & News Contributions: /> Hosted by: Adept Scientific http://www.adeptscience.com List Archive: http://lists.adeptscience.co.uk/ --- Would you like this to come to a different email address? --- Simply leave the mailing list (see below) and re-join by sending a blank email from the new address to: or --- If you do not want to be on the Mathcad list, simply send a blank email (no subject or message needed) to: />

[mathcad] Re: 6 decimal place precision
Author: Jean Rosenfeld    Posted: Tue, 29 Jul 2003 19:50:44 +0100
Sven, No attachment? -------------------------------------------------------- Jean L.J. Rosenfeld Argoed Hall Bryn-y-Baal Mold Flintshire CH7 6SQ Wales, UK Tel +44 1352 750566 E-mail /> -----Original Message----- From: Sven Lindhardt Sent: 29 July 2003 16:52 To: Mathcad Discussion List Subject: [mathcad] Re: 6 decimal place precision Here is another example inspired by Jean, it can handle very small numbers too, Sven ----- Original Message ----- From: "Jean Rosenfeld" /> To: "Mathcad Discussion List" /> Sent: Monday, July 28, 2003 5:33 PM Subject: [mathcad] Re: 6 decimal place precision For floating point numbers greater than 10 the proposed truncation method will not reduce the number of carried decimal places to 6, which is what I understand you want. You need first to divide |z| by factors of 10 until its less than 10, then truncate, then multiply back by the factors of 10 that you divided by. Try the attached. -------------------------------------------------------- Jean L.J. Rosenfeld Argoed Hall Bryn-y-Baal Mold Flintshire CH7 6SQ Wales, UK Tel +44 1352 750566 E-mail /> -----Original Message----- From: Bill Dumke /> Sent: 28 July 2003 01:05 To: Mathcad Discussion List Subject: [mathcad] Re: 6 decimal place precision Sven, I tried your method and thought it might work if I truncated the result of every piece of the whole function. But I found it will not work for floating point complex numbers. Any ideas? See attached file. Bill --- The Mathcad List - Discussion, Support & News Contributions: /> Hosted by: Adept Scientific http://www.adeptscience.com List Archive: http://lists.adeptscience.co.uk/ --- Would you like this to come to a different email address? --- Simply leave the mailing list (see below) and re-join by sending a blank email from the new address to: or --- If you do not want to be on the Mathcad list, simply send a blank email (no subject or message needed) to: /> --- The Mathcad List - Discussion, Support & News Contributions: /> Hosted by: Adept Scientific http://www.adeptscience.com List Archive: http://lists.adeptscience.co.uk/ --- Would you like this to come to a different email address? --- Simply leave the mailing list (see below) and re-join by sending a blank email from the new address to: or --- If you do not want to be on the Mathcad list, simply send a blank email (no subject or message needed) to: />

[mathcad] Re: 6 decimal place precision
Author: Sven Lindhardt    Posted: Tue, 29 Jul 2003 21:08:09 +0200
Sorry about that -:) Sven ----- Original Message ----- From: "Jean Rosenfeld" /> To: "Mathcad Discussion List" /> Sent: Tuesday, July 29, 2003 8:50 PM Subject: [mathcad] Re: 6 decimal place precision Sven, No attachment? -------------------------------------------------------- Jean L.J. Rosenfeld Argoed Hall Bryn-y-Baal Mold Flintshire CH7 6SQ Wales, UK Tel +44 1352 750566 E-mail /> -----Original Message----- From: Sven Lindhardt /> Sent: 29 July 2003 16:52 To: Mathcad Discussion List Subject: [mathcad] Re: 6 decimal place precision Here is another example inspired by Jean, it can handle very small numbers too, Sven ----- Original Message ----- From: "Jean Rosenfeld" /> To: "Mathcad Discussion List" /> Sent: Monday, July 28, 2003 5:33 PM Subject: [mathcad] Re: 6 decimal place precision For floating point numbers greater than 10 the proposed truncation method will not reduce the number of carried decimal places to 6, which is what I understand you want. You need first to divide |z| by factors of 10 until its less than 10, then truncate, then multiply back by the factors of 10 that you divided by. Try the attached. -------------------------------------------------------- Jean L.J. Rosenfeld Argoed Hall Bryn-y-Baal Mold Flintshire CH7 6SQ Wales, UK Tel +44 1352 750566 E-mail /> -----Original Message----- From: Bill Dumke /> Sent: 28 July 2003 01:05 To: Mathcad Discussion List Subject: [mathcad] Re: 6 decimal place precision Sven, I tried your method and thought it might work if I truncated the result of every piece of the whole function. But I found it will not work for floating point complex numbers. Any ideas? See attached file. Bill --- The Mathcad List - Discussion, Support & News Contributions: /> Hosted by: Adept Scientific http://www.adeptscience.com List Archive: http://lists.adeptscience.co.uk/ --- Would you like this to come to a different email address? --- Simply leave the mailing list (see below) and re-join by sending a blank email from the new address to: or --- If you do not want to be on the Mathcad list, simply send a blank email (no subject or message needed) to: /> --- The Mathcad List - Discussion, Support & News Contributions: /> Hosted by: Adept Scientific http://www.adeptscience.com List Archive: http://lists.adeptscience.co.uk/ --- Would you like this to come to a different email address? --- Simply leave the mailing list (see below) and re-join by sending a blank email from the new address to: or --- If you do not want to be on the Mathcad list, simply send a blank email (no subject or message needed) to: />
Attachments:  ctruncate4.mcd

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