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[mathcad] RE: Mathcad bug or programming error?

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[mathcad] RE: Mathcad bug or programming error?
Author: Bury, Scott SJ    Posted: Mon, 28 Jan 2008 12:07:08 -0600
I get the same behavior in v13. Best Regards, Scott (979)-238-1832 ________________________________ From: "Andy.Spragg" "mailto:Andy.Spragg" Sent: Monday, January 28, 2008 7:11 AM To: Mathcad Discussion List Subject: [mathcad] Mathcad bug or programming error? Hi folks, The attached v11 worksheet contains two versions of a program, that I believe to be trivially different. The output from the two versions is utterly different. I spent altogether too long trying to find the error of my ways in one version, before scraping the barrel of reformulation and finding it not to be empty after all. I seek opinions on whether the difference in output is due to Mathcad bug or programming error. If the former is the case, it is a pretty toxic bug (which may of course have long since been squashed). Can anyone please either point out my error, or test these programs in the current version of Mathcad? Andy

[mathcad] RE: Mathcad bug or programming error?
Author: Stuart Bruff    Posted: Mon, 28 Jan 2008 18:29:39 -0000
Andy You've overloaded phi as the end matrix name and the inner summation vector - use a MathStyle to distinguish between the two. Stuartr From: "Andy.Spragg" "mailto:Andy.Spragg" Sent: 28 January 2008 1:11 PM To: Mathcad Discussion List Subject: [mathcad] Mathcad bug or programming error? Hi folks, The attached v11 worksheet contains two versions of a program, that I believe to be trivially different. The output from the two versions is utterly different. I spent altogether too long trying to find the error of my ways in one version, before scraping the barrel of reformulation and finding it not to be empty after all. I seek opinions on whether the difference in output is due to Mathcad bug or programming error. If the former is the case, it is a pretty toxic bug (which may of course have long since been squashed). Can anyone please either point out my error, or test these programs in the current version of Mathcad? Andy -- This message has been scanned for viruses and dangerous content by <http://www.houxou.com/> Houxou, and is believed to be clean.
Attachments:  sumbug1.mcd

[mathcad] Re: Mathcad bug or programming error?
Author: Tom Gutman    Posted: Mon, 28 Jan 2008 21:08:29 -0800
It's a programming error. In the first expression phi is reset to a scalar in the inner loop, hence all the previous columns are lost. Tom Gutman From: "Andy.Spragg" To: Mathcad Discussion List "mathcad" Sent: Monday, January 28, 2008 5:11 AM Subject: [mathcad] Mathcad bug or programming error? > Hi folks, > > The attached v11 worksheet contains two versions of a program, that I > believe to be trivially different. The output from the two versions is > utterly different. I spent altogether too long trying to find the error of > my ways in one version, before scraping the barrel of reformulation and > finding it not to be empty after all. > > I seek opinions on whether the difference in output is due to Mathcad bug > or programming error. If the former is the case, it is a pretty toxic bug > (which may of course have long since been squashed). Can anyone please > either point out my error, or test these programs in the current version > of Mathcad? > > Andy > > > **************************************************************** > Any opinions expressed in this email are those of the individual and not necessarily of RHM Limited and/or any of its subsidiaries. > This email and any files transmitted with it are private, may be confidential and are for the intended recipient only. If you are not the intended recipient, be advised that you have received them in error. Please notify the sender of the error, delete all copies of them from your system and destroy any printed copies. > If you are not the intended recipient, you are not authorized to read, print, retain, copy, disseminate, distribute, or use this email and any files transmitted with it. > Please rely on your own anti-virus system. No responsibility is taken by RHM Limited and/or any of its subsidiaries for any damage arising out of any bug or virus infection. > Registered Office : Premier House, Centrium Business Park, Griffiths Way, St Albans, Hertfordshire, AL1 2RE > Registered No. 3946774 > **************************************************************** >

[mathcad] RE: Mathcad bug or programming error?
Author: Neil Harris    Posted: Tue, 29 Jan 2008 08:36:44 -0000
Hi Andy, Sorry, but it's a programming error. You use phi as the dummy variable in the sum loop and as the vector collecting the results. If you change the name of the dummy variable, it works OK. Neil ________________________________ From: "Andy.Spragg" "mailto:Andy.Spragg" Sent: 28 January 2008 13:11 To: Mathcad Discussion List Subject: [mathcad] Mathcad bug or programming error? Hi folks, The attached v11 worksheet contains two versions of a program, that I believe to be trivially different. The output from the two versions is utterly different. I spent altogether too long trying to find the error of my ways in one version, before scraping the barrel of reformulation and finding it not to be empty after all. I seek opinions on whether the difference in output is due to Mathcad bug or programming error. If the former is the case, it is a pretty toxic bug (which may of course have long since been squashed). Can anyone please either point out my error, or test these programs in the current version of Mathcad? Andy

[mathcad] Re: Mathcad bug or programming error?
Author: William J Marshall    Posted: Mon, 28 Jan 2008 14:37:51 -0500
Hello Andy, Well it sure looks like a bug. Here's a clue: I got function 1 to behave normally by simply replacing the internal variable phi (f CTRL-G) by a non-Greek variable name. What does that say? I hope this helps, Bill "Andy.Spragg" 01/28/2008 12:59 PM Please respond to "mathcad" To Mathcad Discussion List "mathcad" cc Subject [mathcad] Mathcad bug or programming error? Hi folks, The attached v11 worksheet contains two versions of a program, that I believe to be trivially different. The output from the two versions is utterly different. I spent altogether too long trying to find the error of my ways in one version, before scraping the barrel of reformulation and finding it not to be empty after all. I seek opinions on whether the difference in output is due to Mathcad bug or programming error. If the former is the case, it is a pretty toxic bug (which may of course have long since been squashed). Can anyone please either point out my error, or test these programs in the current version of Mathcad? Andy [attachment "sumbug.mcd" deleted by William J Marshall/RES/Raytheon/US]

[mathcad] RE: Mathcad bug or programming error?
Author: Pergande, Albert N    Posted: Mon, 28 Jan 2008 13:48:07 -0500
one difference is in the left function, j goes 2 to I, and inthe right, it goes 2 to I-1 Al Pergande Senior Radar Engineer Lockheed Martin Missiles and Fire Control MP 200 5600 Sandlake Road Orlando, Fl 32819 Voice 407-356-5169 Fax 407-356-0933 "albert.n.pergande" for personal mail - "al" ________________________________ From: "Andy.Spragg" "mailto:Andy.Spragg" Sent: Monday, January 28, 2008 8:11 AM To: Mathcad Discussion List Subject: [mathcad] Mathcad bug or programming error? Hi folks, The attached v11 worksheet contains two versions of a program, that I believe to be trivially different. The output from the two versions is utterly different. I spent altogether too long trying to find the error of my ways in one version, before scraping the barrel of reformulation and finding it not to be empty after all. I seek opinions on whether the difference in output is due to Mathcad bug or programming error. If the former is the case, it is a pretty toxic bug (which may of course have long since been squashed). Can anyone please either point out my error, or test these programs in the current version of Mathcad? Andy

[mathcad] Re: Mathcad bug or programming error?
Author: Chris Whitford    Posted: Tue, 29 Jan 2008 09:32:25 +0000
In f1 you have used the variable phi twice. In the innermost loop (j) change phi to a different name, and all works as expected. Chris At 13:11 28/01/2008 +0000, you wrote: >Hi folks, > >The attached v11 worksheet contains two versions of a program, that I >believe to be trivially different. The output from the two versions is >utterly different. I spent altogether too long trying to find the error of >my ways in one version, before scraping the barrel of reformulation and >finding it not to be empty after all. > >I seek opinions on whether the difference in output is due to Mathcad bug >or programming error. If the former is the case, it is a pretty toxic bug >(which may of course have long since been squashed). Can anyone please >either point out my error, or test these programs in the current version >of Mathcad? > >Andy > + Chris Whitford + Research Fellow, University of Leicester, Space Research Centre, + Physics and Astronomy Department, University Road, LEICESTER LE1 7RH, UK + Tel: +44 116 252 3496, Fax: +44 116 252 2464 + email: "chw" http://www.star.le.ac.uk/

[mathcad] RE: Mathcad bug or programming error?
Author: Pergande, Albert N    Posted: Mon, 28 Jan 2008 15:03:25 -0500
Your problem seems to be in assigning "phi s" to "phi super s". Every time you make the assignment with a new values of S, you create a new phi with a single column vector. I suggest you do phi <-- augment (phi, phi s) You will need to create a dummy vector phi, or handle the column 0 case as an exception. Al Pergande Senior Radar Engineer Lockheed Martin Missiles and Fire Control MP 200 5600 Sandlake Road Orlando, Fl 32819 Voice 407-356-5169 Fax 407-356-0933 "albert.n.pergande" for personal mail - "al" ________________________________ From: "Andy.Spragg" "mailto:Andy.Spragg" Sent: Monday, January 28, 2008 8:11 AM To: Mathcad Discussion List Subject: [mathcad] Mathcad bug or programming error? Hi folks, The attached v11 worksheet contains two versions of a program, that I believe to be trivially different. The output from the two versions is utterly different. I spent altogether too long trying to find the error of my ways in one version, before scraping the barrel of reformulation and finding it not to be empty after all. I seek opinions on whether the difference in output is due to Mathcad bug or programming error. If the former is the case, it is a pretty toxic bug (which may of course have long since been squashed). Can anyone please either point out my error, or test these programs in the current version of Mathcad? Andy

[mathcad] RE: Mathcad bug or programming error?
Author: Zijp, Maarten    Posted: Tue, 29 Jan 2008 09:45:40 +0100
Hi Andy, Sorry to say but to my opinion it is a simple programming error. Inside both for loops you initiliaze your result matrix therefore you will loose all results from pass 1 upto S-1. Mathcad cannot be blamed this time... So, use another variable to store the intermediate results, I used t. You might also considere to either change the upper range of iteration variable j to I-1 as is the case in version two or adapt the upper range for j in function f2 in the summation...... kind regards Maarten Zijp Maarten Zijp room 5045 Information Technology Group Leerstoelgroep Toegepaste Informatiekunde Social Sciences Group Wageningen University Leeuwenborch (Building 201) Hollandseweg 1 6706 KN Wageningen The Netherlands tel (0)317-484079 fax(0)317-483158 E-mail: "maarten.zijp" internet: http://www.inf.wur.nl/ <http://www.inf.wur.nl/> ________________________________ From: "Andy.Spragg" "mailto:Andy.Spragg" Sent: 28 January 2008 14:11 To: Mathcad Discussion List Subject: [mathcad] Mathcad bug or programming error? Hi folks, The attached v11 worksheet contains two versions of a program, that I believe to be trivially different. The output from the two versions is utterly different. I spent altogether too long trying to find the error of my ways in one version, before scraping the barrel of reformulation and finding it not to be empty after all. I seek opinions on whether the difference in output is due to Mathcad bug or programming error. If the former is the case, it is a pretty toxic bug (which may of course have long since been squashed). Can anyone please either point out my error, or test these programs in the current version of Mathcad? Andy
Attachments:  Outlook.jpg

[mathcad] Re: Mathcad bug or programming error?
Author: Eden Mei    Posted: Mon, 28 Jan 2008 11:12:39 -0800
Looks to me like a programming error. The line immediately following the rnorm is loada the array with zeros, but you do this on every iteration, so every iteration, the array is again zeroed, until the last iteration, when columns 10 and 11 get populated but not zeroed. This is something that you don't do at all in the second program, so your claim of them being trivially different is not. Part of the problem is that you're using the same variable in two different places for two different things. From: "Andy.Spragg" To: Mathcad Discussion List Sent: Monday, January 28, 2008 5:11 AM Subject: [mathcad] Mathcad bug or programming error? Hi folks, The attached v11 worksheet contains two versions of a program, that I believe to be trivially different. The output from the two versions is utterly different. I spent altogether too long trying to find the error of my ways in one version, before scraping the barrel of reformulation and finding it not to be empty after all. I seek opinions on whether the difference in output is due to Mathcad bug or programming error. If the former is the case, it is a pretty toxic bug (which may of course have long since been squashed). Can anyone please either point out my error, or test these programs in the current version of Mathcad? Andy

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