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| bio | website | verbeia.com/mathematica/tips/… |
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| age | ||
| visits | member for | 1 year, 3 months |
| seen | 54 mins ago | |
| stats | profile views | 260 |
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May 18 |
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How to create internally optimized expression for computing with high WorkingPrecision? performing arithmetic operations in the right way can reduce round off errors. One important example is use of HornerForm (a built in function) for computing polynomials. Most text books on numerical methods show a few other tricks for specific cases. It's all about avoiding catastrophic cancelation, which is the loss of precision due to subtracting numbers that are nearly equal but not close to zero. |
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May 18 |
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How to create internally optimized expression for computing with high WorkingPrecision? It might work better if you make jacobianMatrix a CompiledFunction. That will help if FindMinimum uses MachinePrecision to get close to the optimal solution, and switch to higher precision for fine tuning. |
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Feb 2 |
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ListPlot and Union related question Back when I was in school, I did my homework myself. It's too bad the OP doesn't feel like thinking about this, because they can't learn much by copying code somebody else wrote. |
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Jan 31 |
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What are the use cases for different scoping constructs? Yet another scoping construct that I didn't see mentioned is DynamicModule. |
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Jan 12 |
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Interactive steam tables and phase diagrams in Mathematica For years I have wondered why Wolfram hasn't included each steam table as an InterpolatingFunction. |
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Oct 28 |
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A good way to manage code in a complicated CDF? I saw SaveDefinitions before, but couldn't remember what it's called. I think that's the solution to my problem. Although I haven't had a chance to try it. I would accept it as an answer if you entered your comment as an answer. |
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Aug 28 |
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Creating a Tooltip that knows what platform is currently being used This is the best criteria to use. However, failure to use Dynamic (See RM's solution) is real cause of my problem. |
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Aug 19 |
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Compiled version of (Norm/@coordinates) Silly me, I checked the list of compileable functions and didn't see it. I also didn't know about Internal`Square. |
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Aug 14 |
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How to switch between different CDFs in CDF Player? @ Mark McClure See my edit above |
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Jul 29 |
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What is the difference between Set and SetDelayed? I discuss that in great detail here. |
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Jul 16 |
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Can't get Workbench to debug Each time I asked "how can I ...", I got a very good answer. It's just that I haven't learned about 'accepting' answerrs. Going into chat now. |
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Jul 16 |
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Can't get Workbench to debug Deleting the Mma 7.0 path solved the issue. Haven't had a chance to so much, but then I couldn't get my break point working. |
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Jun 18 |
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The difference between 0. and 0 We also have 0.0*I which is a complex number that is approximately zero. Also have 0.0''200 which is a real number known to have absolute value less than 10^-200. I find it inconsistent that Head[Re[0.0 I]] is Real, but Head[Re[1.0''200 I ]] is Integer. |
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Jun 18 |
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The difference between 0. and 0 Mma has other fl |
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Jun 12 |
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Can't get DynamicModule[{..},..EventHandler[] ] working Sorry for being a pain, but I still haven't learned how to format the code. Much of the time I come here using my iPhone which has many features in stack exchange missing. Sometime when I am at home, I will try to contact one of you on chat and learn some stuff. Want my email address? |
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Jun 12 |
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When to make (file.nb) instead of (file.cdf)? there is more to it than that. WRI could have made it so you can't use the Option Inspector to modify a CDF file. They could have made it so you can't use Drawing Tools in a CDF file. It turns out you can use Mathematica to do these things, but you can't know that from looking at the file with a text editor. I found out that I can do those things because I tried and they worked. The problem is that there are a few hundred other features that may or may not work. |
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May 13 |
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Does Mathematica have advanced indexing? I like the UnitStep, ReplacePart solutions a lot. Some of the other solutions are very complicated and sure to turn off people who are new to Mathematica. .... I think I finally figured out how and when to 'Add Comment' in this forum :) |
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Apr 13 |
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How does Interpolation really work? I understand cubic spline interpolation has a few different varieties depending what the derivative does at the end points. I thought InterpolationOrder->3 used a cubic spline interpolation. Is a cubic spline interpolation a specific case of a B-Spline? |
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Apr 6 |
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Expression evaluation inside of FindRoot inside a Compiled Function In that case you still might be able to improve performance if your compiled code includes a root-finding method built from scratch. It looks like you are doing root finding in 1D. If you know you can start with two points where the function changes sign Brent's method is a great choice. I could provide a Mma implementation of Brent's method. If you can't use Brent's method, another method such as Newton's method or secant method might work well. They are both easy to implement. You may also need to roll your own version of other function that can't be compiled. |
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Feb 22 |
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Are there any cases when For[] loops are reasonable? In my RootSearch package I call an iterative algorithm which looks for a root where there is likely to be a root. That algorithm calls a function which calls a function and so on. A few functions deep it may be discovered that the function whose roots we a looking fo is not defined at the new approximation of the root. When that happens I use Throw to give up on the iterative algorithm in that neighborhood. I don't know if you call that an exception. Also, we can use Check to take certain action when we compute 0/0 etc. |
