 Rank: Newbie
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Joined: 22/09/2010(UTC)
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Location: Hungary
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Hello! I have problem vith the units. I already have several smath file that I made with one of the previous versions. By recalculating these with the use of the latest version, there are a lot of mistakes, and it doesent works at all. Maybe because by me the new version makes strange simplifications by units. It cant add the proviously calculated "s*1" (secundum multiplied with one) and for example "s^1". An other strange thing is that sometimes (when trigonometrics or roots are in the equation) For example A:=equation I got different results for: A= and equation= If you can, please help me. Sorry for my bad english. L.R. Edited by moderator 17 May 2012 22:08:09(UTC)
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  Rank: Administration Groups: Developers, Registered, Knovel Developers, Administrators, Advanced Member Joined: 11/07/2008(UTC) Posts: 1,616   Was thanked: 1978 time(s) in 666 post(s)
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Radnay, please send file(s) to me and I will check the reason of the errors you've mentioned.
Best regards.
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Rank: Newbie
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Joined: 22/09/2010(UTC)
Posts: 9
Location: Hungary
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 Rank: Administration Groups: Registered, Advanced Member Joined: 23/06/2009(UTC) Posts: 1,740  Was thanked: 318 time(s) in 268 post(s)
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Hello, I tried the *.sm file and this time Numeric and None optimization will fail complaining about unmatching units. Symbolic optimization will give the results.  If we assign the expression to the variable RES here, only the Symbolic optimization will give the result. Numeric and None will fail. Regards, Radovan |
When Sisyphus climbed to the top of a hill, they said: "Wrong boulder!" |
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Rank: Newbie
Groups: Registered
Joined: 22/09/2010(UTC)
Posts: 9
Location: Hungary
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Rank: Administration Groups: Registered, Advanced Member Joined: 23/06/2009(UTC) Posts: 1,740 Was thanked: 318 time(s) in 268 post(s)
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Hello, I have no idea what has going on, sorry. This might be some kind of a bug. For instance, this is an error from your file:  Do not even know what was the error about. What actually "1E" means? Andrey is the only one who can give the right answer. Regards, Radovan |
When Sisyphus climbed to the top of a hill, they said: "Wrong boulder!" |
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Rank: Newbie
Groups: Registered
Joined: 22/09/2010(UTC)
Posts: 9
Location: Hungary
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Hi!
I'm glad that I could at least describe my problem.
This file worked properly half year ago, with the actual version.
I look forward for your help.
L.R.
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Rank: Newbie
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Here I am again. http://www.mfk.unideb.hu...zlo.radnay/smatherror.smIn this I have made the changes that you recommended Radovan. I had to modify the datas to show this: In the bottom of the page I have calculated the value of "A" on the basis of the datas, calculated by the program previously. The results are different. This is the other thing I have mentioned in my first comment. L.R.
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Rank: Administration Groups: Registered, Advanced Member Joined: 23/06/2009(UTC) Posts: 1,740 Was thanked: 318 time(s) in 268 post(s)
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Hello Radnay,
I just have to repeat that there are obviously some problems in the SMath calculations regarding your examples. It is good that you found this and reported it as well.
I also know that Andrey will answer on this and find what the problem was as soon as he can.
Regards,
Radovan |
When Sisyphus climbed to the top of a hill, they said: "Wrong boulder!" |
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Rank: Administration Groups: Developers, Registered, Knovel Developers, Administrators, Advanced Member Joined: 11/07/2008(UTC) Posts: 1,616 Was thanked: 1978 time(s) in 666 post(s)
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I would classify this as a bug. Will fix it. Thanks.
Best regards, Andrey Ivashov.
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  Rank: Member Groups: Registered
Joined: 13/05/2011(UTC)
Posts: 17
Location: coolum bch, Australia
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Hi guys,
On the subject of units, I need a little prod...
Smath fastracks a lot of high end maths, I must concede though all of my stuff is low brow and my use of the program directed at formalising repetitive tasks (this the program also does well...!)
The units confound me though....
The program can ignore the units I have used and substitute it's own.
Can I convert the answer into the units I want....?
cheers,
Stu.
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Rank: Administration Groups: Registered, Advanced Member Joined: 23/06/2009(UTC) Posts: 1,740 Was thanked: 318 time(s) in 268 post(s)
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Hello Stu, studoc wrote:The program can ignore the units I have used and substitute it's own.
Can I convert the answer into the units I want....? Yes, you can. See for example this tutorial please, Equations and Units starting from page 5. Regards, Radovan Edited by user 29 April 2012 12:24:33(UTC)
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When Sisyphus climbed to the top of a hill, they said: "Wrong boulder!" |
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Rank: Member Groups: Registered
Joined: 13/05/2011(UTC)
Posts: 17
Location: coolum bch, Australia
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Thanks for that Radovan, just the sort of thing I needed...
I do get some interesting results, including the original units, in my answer though...
For this time it's far easier to enter the units as text only, i'll keep this info handy and endeavour incorporate it in the next project...
thanks...!
Stu.
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Rank: Administration Groups: Registered, Advanced Member Joined: 23/06/2009(UTC) Posts: 1,740 Was thanked: 318 time(s) in 268 post(s)
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You are welcome, Stu, studoc wrote:I do get some interesting results, including the original units, in my answer though...
For this time it's far easier to enter the units as text only, i'll keep this info handy and endeavour incorporate it in the next project... If you find something that does look suspicious or problematic to you regarding units, just report it. That might be a bug and all of us will be grateful to you if you find one. The user feedback is very important to SMath project, especially reported possible bugs in order to get fixed. Regards, Radovan Edited by user 29 April 2012 13:41:27(UTC)
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When Sisyphus climbed to the top of a hill, they said: "Wrong boulder!" |
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Rank: Member Groups: Registered
Joined: 13/05/2011(UTC)
Posts: 17
Location: coolum bch, Australia
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Hi,
Having another look at this, don't know if it's so much a possible bug, as much as my lack of understanding, but it grinds me to a halt...
I looked through your link and am relying on the last section (complex conversions) to reliably establish my units (tick that box), but the calculation.....
If we consider that weight equals mass times acceleration due to gravity,
vis.
W=mg
I can declare the units of mass as, "kg" and the units of acceleration due to gravity as, "m/s^2", but when I enter, "W=" there is no result... Hovering over the expression shows the message, "operation cannot be performed with units", but we all know the units are, "N".
In a simple example, this is the sort of thing I am endeavouring to straighten out, can I.....?
cheers,
Stu.
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Rank: Administration Groups: Registered, Advanced Member Joined: 23/06/2009(UTC) Posts: 1,740 Was thanked: 318 time(s) in 268 post(s)
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Hello Stu, I did not quite understand you, sorry. But Here is a simple example:  Pay attention the black and blue variables. Blue variables are "units" and they are different from the black variables with the same name. I used (above the separation line) "g" but this is apredefined variable inside the unit SMath system - therefore is in blue color. Below the line I used "g" as a variable in SMtah and then represented "W" in different units. Just click on it and start typing. The Dynamic assistnce will show you the list and you can choose the desired one (by TAB or double click on it)  Regards, Radovan |
When Sisyphus climbed to the top of a hill, they said: "Wrong boulder!" |
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Rank: Administration Groups: Developers, Registered, Knovel Developers, Administrators, Advanced Member Joined: 11/07/2008(UTC) Posts: 1,616 Was thanked: 1978 time(s) in 666 post(s)
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The initial issue fixed:  Regards.
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 1 user thanked Andrey Ivashov for this useful post.
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