 Rank: Newbie
Groups: Registered
Joined: 28/09/2009(UTC)
Posts: 3
Location: UK
|
I found a problem with the plot function when using it with the McLaurin example.
If you set the series order N to any value greater than 26 then the plotted data is incorrect.
Both the f(x) = sin(x) and the fmc(x)= MacLaurin expansion appear to be incorrect as the amplitude becomes greater than 1.
It looks as if the error is in the fmc(x) function. This causes the plot to misbehave if fmc(x) cannot be calculated.
|
|
|
|
|
|
  Rank: Administration Groups: Registered, Advanced Member Joined: 23/06/2009(UTC) Posts: 1,740   Was thanked: 318 time(s) in 268 post(s)
|
Hello, I think this is connected with the Symbolic SMath Studio engine. It is not connceted to this example only. Just take a look at the picture:  Note the error message. This error will be issued when SMath is forced to deal with a complicated symbolic expressions (in this case quite a complicated large order polynomial is included). For instance, when I try to solve four or five nonlinear equations with the included SMath example which uses Newton-Raphson method for solving set of nonlinear equations it is quite likely that the same error will be issued. Therefore, I think that this is a general SMath problem with large integers, which should be investigated. For instance: 200!—#Will give the same error message. Is there any way to change this and to get the result? I do not know. Try this in Mathcad, you will get the result even with bigger factorials. Regards, Radovan Edited by user 29 September 2009 13:10:39(UTC)
| Reason: Not specified |
When Sisyphus climbed to the top of a hill, they said: "Wrong boulder!" |
|
|
|
|
|
Rank: Newbie
Groups: Registered
Joined: 28/09/2009(UTC)
Posts: 3
Location: UK
|
Hi Radovan,
I agree with what your comments and yes I would like the symbolic solver to be better.I've tried your suggestion in Mathcad and got 500! to work quickly. Then windowsXP just froze when I tried 10000!. That was really annoying.
However I am reporting a bug I found a with the 2D Plot. When I try N>27 the plot of f(x) is also wrong not just fmc(x). f(x) has a amplitude of about 1.8 when it should be 1.0. I can understand fmc not plotting due to the limitations of the symbolic engine, f(x) should at least be plotted correctly. Your picture does not show this problem so I guess it may not be a generic problem with the plot but specific to my configuration.
I'm running smath v0.85 build 3531 on WindowsXP SP3. I also have .NET frameworks up to v4.0.20506 installed.
Also, I would appreciate it if you can let me know how you inserted the picture in your post as I cannot work out how to do this.
Thanks
Hetal
--
|
|
|
|
|
|
Rank: Administration Groups: Registered, Advanced Member Joined: 23/06/2009(UTC) Posts: 1,740 Was thanked: 318 time(s) in 268 post(s)
|
Hello Hetal patel75 wrote:
However I am reporting a bug I found a with the 2D Plot. When I try N>27 the plot of f(x) is also wrong not just fmc(x). f(x) has a amplitude of about 1.8 when it should be 1.0. I can understand fmc not plotting due to the limitations of the symbolic engine, f(x) should at least be plotted correctly. Your picture does not show this problem so I guess it may not be a generic problem with the plot but specific to my configuration.
I'm running smath v0.85 build 3531 on WindowsXP SP3. I also have .NET frameworks up to v4.0.20506 installed.
Yes, it seems you are right. There is a problem (maybe a bug) with this build (I can reproduce your findings. Even a crash can occur if I tried to scale the plot). You can try to use (as I did) build 3545 (not the official one) and you can download it from: http://en.smath.info/forum/default.aspx?g=posts&t=214Try with this one. I made a test with it and it seems this problem has been fixed. patel75 wrote:
Also, I would appreciate it if you can let me know how you inserted the picture in your post as I cannot work out how to do this.
Upload the picture on some free file hosting site. Then make a link to it by using "Insert image" button when posting. I am using SMath upload site, but it is in Russian only at the moment. You can also upload files on the SMath WIKI (yellow button) and make a link to it. Also, you are invited to freely put some pages on the WIKI if you like. Regards, Radovan Edited by user 02 October 2009 21:43:01(UTC)
| Reason: Not specified |
When Sisyphus climbed to the top of a hill, they said: "Wrong boulder!" |
|
|
|
|
|
Forum Jump
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.
