Nasser
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 Sep 24 comment Manipulating parameters in a complex algorithm If you look at this link it summarizes all the different cases for Manipulate. For you example, I would use the second argument of dynamics, it is the most flexible way to handle very complicated events and interactions since it is based on then event/callback way of looking at things. Sep 23 comment NDSolve giving the wrong solution? ... the one you showed y=-4*x/(1+3*x). The point is, these are singular solutions. There is a singularity in your ode, which is why NDSolve gives a 1/0 error. So, there is nothing wrong with NDSolve. Notice that DSolve did not solve this. Sep 23 comment NDSolve giving the wrong solution? do not have time now, but quick comment: you have non-linear ode. A non-linear ode can admit a singular solution (which can't be obtained from the general solution by giving the constants of integration specific values). Another solution is y=-2. Another is y=(-4*((x^4-2*x^2+1)/(x^4+8*x^3+18*x^2+8*x+1))^(1/2)*x^4-20*((x^4-2*x^2+1)/(x^4‌​+8*x^3+18*x^2+8*x+1))^(1/2)*x^3-4*x^4-24*((x^4-2*x^2+1)/(x^4+8*x^3+18*x^2+8*x+1))‌​^(1/2)*x^2-16*x^3-20*((x^4-2*x^2+1)/(x^4+8*x^3+18*x^2+8*x+1))^(1/2)*x-32*x^2-4*((‌​x^4-2*x^2+1)/(x^4+8*x^3+18*x^2+8*x+1))^(1/2)-16*x-4)/(3*x^4+8*x^3+14*x^2+8*x+3) as well as the.. Sep 22 comment Is this integral solvable? You can try the free Wolfram cloud, it has Mathematica there for free wolfram.com/programming-cloud/pricing click on the free option. Also can try Wolfram alpha, it is supposed to be able to do integration as well. Sep 22 comment How to remove error at large time in NDSolve it works ok for me using V 10.01 on windows. moved the slider all the way to the right and I see no errors. !Mathematica graphics may be you can upgrade to 10.01 Sep 18 comment Tracking Initialization @MichaelE2 I know for Manipulate that the following happens, and I would assume the same for DyanmicModule, since Manipulate is just a DynamicModule: The body of Manipulate (the expression part) is checked for valid input/form, but it is not evaluated until Initialization is finished. The question of when Initialization is run or not is separate. But when it needs to be evaluated, then yes, the body/dynamics/expression will wait until Initialization is finished running. Sep 18 comment Tracking Initialization I do not think what I said is different from what you are saying. Initialization is evaluated to generate the dynamic expression first time it is needed to be displayed on the screen. Sep 17 comment Tracking Initialization I am not sure I understand what you mean by this tracking to be reflected in Dynamic updating Since Initialization is processed once from top down. (to generate the initial expression). Once this is done, Initialization basically goes away. Sep 17 comment Tracking Initialization You can always use Print :) DynamicModule[{x}, Dynamic[x], Initialization :> (x = 1; Print["x=2"]; x = 2; Print["x=3"]; x = 3) ] Sep 16 comment Manipulate a parameter within the PlotLabel f = {1, 2, 3, 4, 5, 6}; Manipulate[ Plot[Sin[f[[g]] x], {x, -2, 2}, PlotLabel -> Row[{"f = ", f[[g]]}]], {{g, 1, "index"}, 1, Length[f], 1, Appearance -> "Labeled"} ] Sep 5 comment Mathematica 10 loads too long time fyi, some discussion related here community.wolfram.com/groups/-/m/t/291612?p_p_auth=CDjlQwC5 "Can my start up time for Mathematica 10 be decreased?" do not know if it is the same issue as you are having. Sep 4 comment Giving hints to Integrate could you rewrite this without using the letter l as variable? Makes it hard to read as you have 1 and l next to each others. Aug 31 comment Real and Imaginary parts of solutions to a complex linear ODE system Is there an issue with getting the solution and then using Re and Im to separate the real and imaginary parts? May be coupled with the use of ComplexExpand? A full MWE also helps. Aug 29 comment After editing a file Mathematica 10 interprets […]^2 as […(])^2 I can't reproduce it. V10 on windows. Screen shot. !Mathematica graphics may be you have some hidden char inserted by mistake. If you post the notebook somewhere may be someone can better help you. Aug 28 comment InterplationOrder, ListPlot3D and using AbsoluteOption to find value used. Slow using InterpolationOrder I see. So none of options such as PlotStyle used can be queried using AbsoluteOptions. Just tried it on normal plot: p0 = Plot[Sin[x], {x, -1, 1}, PlotStyle -> Red]; AbsoluteOptions[p0, PlotStyle] and this also gave an error. This makes AbsoluteOptions not as useful as I thought before. May be this is what the book means by "special options" in the screen shot I posted. Thanks. Aug 28 comment InterplationOrder, ListPlot3D and using AbsoluteOption to find value used. Slow using InterpolationOrder @Mr.Wizard Yes, but this is one part of it. The other part is why I get an error when query this option? I did not want to split this to 2 questions. But may be I should have. What do you think? Should they be separate? I can do that. ps. the slow down is really large as can be seen by the numbers. A bit of slow down ok, but 10 times slower? Aug 28 comment The correct pattern for Cases nice. May be you explain a little for us newbies how this works :) Aug 23 comment Error when using EquationTrekker on version 10, windows 7, it hanged. But I saw message Message text not found -- (PropertyValue[{canvas ,canvasPane ,All},Name->trekPane ]) (1) >> show up before it hanged Aug 21 comment How to combine one or more rotated graphics objects? Would'nt be easier to just change the order of Graphics and Rotate? Like this: e1 = Graphics[Rotate[{Blue, Opacity[.75], Disk[{0, 0}, {1/3, 1/4}]}, \[Pi]/3]]; e2 = Graphics[Rotate[{Red, Opacity[.75], Disk[{0, 0}, {1/3, 1/4}]}, \[Pi]/7]]; Show[{e1, e2}] !Mathematica graphics Jul 22 comment Is there a list of Octave functions mapped to the related Mathematica one? there are lots of problems solved by Matlab and Mathematica side-by-side here