DotNumerics

DotNumerics - Initial-value problem for nonstiff and stiff ordinary differential equations ODEs - Messages

#21 Posted: 8/1/2018 12:54:24 PM
Вячеслав Мезенцев

Вячеслав Мезенцев

1,526 likes in 1,835 posts.

Group: Moderator

Simple test 2.

DotNumerics.ode.test2.png

DotNumerics.ode.test2.sm (21.23 KiB) downloaded 754 time(s).
DotNumerics.ode.test2.pdf (79.99 KiB) downloaded 394 time(s).
Russia ☭ forever, Viacheslav N. Mezentsev
2 users liked this post
sergio 8/1/2018 6:06:00 PM, Radovan Omorjan 8/2/2018 3:05:00 AM
#22 Posted: 8/1/2018 9:57:14 PM
Jean Giraud

Jean Giraud

983 likes in 6,866 posts.

Group: User

Wrote

Simple test 2.


Works nice conventional/visual [6179].
That document, if it would come from other designer
would pass my QA [Quality Assurance].

Jean

DotNumerics.ode.test2.sm (24.51 KiB) downloaded 772 time(s).

#23 Posted: 9/9/2018 2:23:36 PM
Martin Kraska

Martin Kraska

1,285 likes in 2,205 posts.

Group: Moderator

It seems that all the dotnumeric ode solver functions fail to add the last step to the solution. In the given example, the exact solution is (approximately) met if the end value of x is increased by one step (x_end/steps).

The sheet is easily extended to whatever ode solvers by adding their name to the search list. The actually available solvers depend on what plugins are installed.

Section Math ODE precision.sm (23.66 KiB) downloaded 818 time(s).
Section Math ODE precision.png
Martin KraskaPre-configured portable distribution of SMath Studio: https://en.smath.info/wiki/SMath%20with%20Plugins.ashx
2 users liked this post
frapuano 9/9/2018 5:18:00 PM, Вячеслав Мезенцев 9/10/2018 5:37:00 AM
#24 Posted: 9/10/2018 6:48:25 AM
Вячеслав Мезенцев

Вячеслав Мезенцев

1,526 likes in 1,835 posts.

Group: Moderator

Updated for SS 0.99.6824. Intervals issue fixed.
Russia ☭ forever, Viacheslav N. Mezentsev
3 users liked this post
sergio 9/10/2018 7:02:00 AM, frapuano 9/10/2018 9:23:00 AM, NDTM Amarasekera 9/10/2018 9:48:00 AM
#25 Posted: 12/6/2018 2:42:53 PM
Вячеслав Мезенцев

Вячеслав Мезенцев

1,526 likes in 1,835 posts.

Group: Moderator

Updated.

Changes:
- zero point issue fixed;
- added support for the simple D(t,x) definition.
Russia ☭ forever, Viacheslav N. Mezentsev
#26 Posted: 12/24/2018 9:13:53 AM
Вячеслав Мезенцев

Вячеслав Мезенцев

1,526 likes in 1,835 posts.

Group: Moderator

Updated.

2018-12-24_17-06-48.png 2018-12-25_04-33-23.png 2018-12-25_04-34-24.png dn.ode.test2.png dn.ode.test1.png 2018-12-24_17-07-41.png

dn.ode.kinetic1.sm (8.26 KiB) downloaded 881 time(s).
dn.ode.kinetic2.sm (12.59 KiB) downloaded 826 time(s).
dn.ode.kinetic3.sm (12.28 KiB) downloaded 823 time(s).
dn.ode.test1.sm (19.58 KiB) downloaded 830 time(s).
dn.ode.test2.sm (18.88 KiB) downloaded 833 time(s).
dn.ode.Amplitude detector.sm (20.17 KiB) downloaded 844 time(s).

dn.ode.kinetic1.pdf (77.42 KiB) downloaded 477 time(s).
dn.ode.kinetic2.pdf (93.05 KiB) downloaded 459 time(s).
dn.ode.kinetic3.pdf (91.31 KiB) downloaded 445 time(s).
dn.ode.test1.pdf (115.72 KiB) downloaded 452 time(s).
dn.ode.test2.pdf (120.44 KiB) downloaded 444 time(s).
dn.ode.Amplitude detector.pdf (148.87 KiB) downloaded 439 time(s).
Russia ☭ forever, Viacheslav N. Mezentsev
4 users liked this post
NDTM Amarasekera 12/24/2018 9:44:00 AM, sergio 12/24/2018 11:04:00 AM, frapuano 12/24/2018 2:23:00 PM, Radovan Omorjan 12/24/2018 2:52:00 PM
#27 Posted: 12/25/2018 2:49:08 PM
Jean Giraud

Jean Giraud

983 likes in 6,866 posts.

Group: User

Native works as well.
You can try rkfixedSteven.

rkNative.PNG

rkfixedSteven.PNG
#28 Posted: 12/25/2018 4:25:11 PM
Jean Giraud

Jean Giraud

983 likes in 6,866 posts.

Group: User

1 users liked this post
frapuano 12/25/2018 7:01:00 PM
#29 Posted: 12/9/2021 9:10:25 AM
Вячеслав Мезенцев

Вячеслав Мезенцев

1,526 likes in 1,835 posts.

Group: Moderator

SMath Studio compatibility

Plugin updated.

Changes:

- added support the mathematical form of the problem for ODE solvers;
- refactored.
Russia ☭ forever, Viacheslav N. Mezentsev
1 users liked this post
sergio 12/9/2021 11:40:00 AM
#30 Posted: 12/20/2021 4:18:13 PM
Вячеслав Мезенцев

Вячеслав Мезенцев

1,526 likes in 1,835 posts.

Group: Moderator

SMath Studio compatibility

Plugin updated.

Changes:

- solution restructured;
- converting the task for the ODE solver to the numerical form is now performed through the Mathcad Toolbox plugin (to avoid code duplication), so it must be installed;
- refactored.

Solvers that support mathematical notation now reuse code from the Mathcad Toolbox plugin. Now there is no need to recompile every such plugin.
Russia ☭ forever, Viacheslav N. Mezentsev
#31 Posted: 8/21/2022 2:43:28 AM
Alvaro Diaz Falconi

Alvaro Diaz Falconi

1,073 likes in 1,739 posts.

Group: User

Hi Viacheslav. There are an issue with Implicit and dn_ExplicitRK45, just in the first element. Please see the attached.

dn_ExplicitRK45 issue.sm (8.42 KiB) downloaded 707 time(s).

Best regards.
Alvaro.
1 users liked this post
Вячеслав Мезенцев 8/22/2022 3:11:00 AM
#32 Posted: 8/22/2022 3:12:45 AM
Вячеслав Мезенцев

Вячеслав Мезенцев

1,526 likes in 1,835 posts.

Group: Moderator

SMath Studio compatibility

Plugin updated.

Changes:

- fixed values of initial conditions in the output array for dn_ImplicitRK5() and dn_ExplicitRK45().
Russia ☭ forever, Viacheslav N. Mezentsev
2 users liked this post
sergio 8/22/2022 4:19:00 AM, Alvaro Diaz Falconi 8/23/2022 8:15:00 PM
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