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| bio | website | |
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| location | ||
| age | ||
| visits | member for | 1 year, 3 months |
| seen | May 16 at 18:48 | |
| stats | profile views | 121 |
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Mar 28 |
revised |
NIntegrate is resetting my variables and not giving me a result? Tried to reduce the quantity of text. |
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Mar 28 |
comment |
NIntegrate is resetting my variables and not giving me a result? @R.M Yes, I realize that. I don't know where else I could post the code itself so as to focus on the problem that the code is stricken by here! :( |
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Mar 28 |
comment |
What does MaxStepFraction do? This makes sense, thank you. |
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Mar 28 |
asked | NIntegrate is resetting my variables and not giving me a result? |
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Mar 28 |
accepted | What does MaxStepFraction do? |
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Mar 28 |
revised |
What does MaxStepFraction do? Correcting an error. |
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Mar 28 |
comment |
What does MaxStepFraction do? @F'x I apologize. I am getting careless. I meant MaxStepFraction and NOT MaximumStepFraction. I've also included some more thoughts about this option in EDIT 2. |
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Mar 28 |
revised |
What does MaxStepFraction do? edited body |
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Mar 28 |
revised |
Setting the DifferenceOrder Option There was also a syntax error in my mathematica program. I thought adding the "syntax" tag would draw attention to that. |
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Mar 28 |
accepted | Setting the DifferenceOrder Option |
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Mar 28 |
comment |
Setting the DifferenceOrder Option Yes thats exactly what I did -- set the "MaxDifferenceOrder"->1. I find that now, I get better convergence than the authors by decreasing the "MaxStepFraction". Forgive me as I am a sophomore at mathematica and I did post a further question about "MaxStepFraction" here! :( but I am getting closer to understanding NDSolve better. |
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Mar 28 |
asked | What does MaxStepFraction do? |
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Mar 28 |
comment |
Setting the DifferenceOrder Option Sure thing! The results I am trying to compare with are here. The authors have used a Backward Euler method for their nonlinear equation. I read from a couple of books that the Backw'd Euler method is actually the BDF method to order 1 and hence I am trying to implement the same. |
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Mar 28 |
comment |
Setting the DifferenceOrder Option that makes sense considering that it's called the "MaxDifferenceOrder". But it is rather unfortunate that I can't quite change the order and fix it manually. That makes comparison with published results and consequently publishing my results virtually impossible. |
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Mar 28 |
comment |
Setting the DifferenceOrder Option I find that fixing the "MaxDifferenceOrder" in BDF does have an effect on the result. A higher order did get me closer to the solution. I hope I am not understanding that all wrong! :P |
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Mar 28 |
comment |
Setting the DifferenceOrder Option This is a really interesting comment. The reason I am interested in fixing the order to a user defined value is that it makes comparison with published data so much more easier. |
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Mar 28 |
revised |
Setting the DifferenceOrder Option added 216 characters in body |
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Mar 28 |
comment |
Setting the DifferenceOrder Option @rcollyer You are right. However, is running IDA with Newtons method and "MaxDifferenceOrder"->5 the same as running BDF with "MaxDifferenceOrder"-> 5? They both run without errors. |
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Mar 28 |
revised |
Setting the DifferenceOrder Option Might have found possible solution. Open to more ideas and suggestions. |
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Mar 28 |
revised |
Setting the DifferenceOrder Option More information being provided as to progress |
