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Sep
27
comment Solving vector equations
Maybe x = {x1, x2}; a = {8, -2}; b = {3, 3}; Solve[x + a == b, x] gives {{x1 -> -5, x2 -> 5}}
Sep
27
comment Convert imported PDF to an image
@DJS I am not following what you mean. images types such as png, jpeg, gif, etc... are file-based image formats, and not in-memory based image formats. Once read, they are converted to Mathematica Graphics. For example, to covert png to gif, you'd import the png file to Mathematica, then export it back as gif. Or may be I am not understanding what you mean by the question.
Sep
25
comment Real time visualization of parametric plots
try f = {Cos[s/Sqrt[2]], -Sin[s/Sqrt[2]], s/Sqrt[2]}; Manipulate[ ParametricPlot3D[f, {s, -z, z}, PlotRange -> {{-1, 1}, {-1, 1}, {-2, 2}}], {{z, .1, "extent"}, .1, 2 Pi, .1, Appearance -> "Labeled"} ] and click on the play arrow in the control for "extent" to see the animation
Sep
25
comment Manipulating parameters in a complex algorithm
I just copied your code and it ran as is. Here is screen shot. !Mathematica graphics maybe this function was not used when I run it. do not know.
Sep
25
comment How can I load << MathWorld`Curves`?
I have all the packages, but they are not updated to new version of M. For example, this one does not run on V10.1 since it uses BeginPackage["MathWorldCurves",{"UtilitiesFilterOptions"}] and "Utilities`FilterOptions" is no longer supported, see reference.wolfram.com/language/Compatibility/tutorial/Utilities/… so even if get these files, someone needs to update them to run in new M. May be contact the original author and see if there is newer version. The Mathworld packages I have are called version 6. I think that was the zip file name. Do not remember now.
Sep
25
comment Plotting (Graphing) a Quadratic Function with Vertex and Roots
I added small description below
Sep
25
comment Plotting (Graphing) a Quadratic Function with Vertex and Roots
Is this what you want: r1 = 15/10 + I Sqrt[7]/2; p = Expand[(x - r1)*(x - Conjugate[r1])] Plot[p, {x, -3, 3}] which gives on V 10.01 !Mathematica graphics the poly is 4-3 x+x^2
Sep
25
comment Manipulating parameters in a complex algorithm
it looks good. Tried it, was little slow when N was 500 and higher. May be this is algorithm tune-up. But if it works for you and no more issues, then you can answer your own question with your answer above. Unless you have any specific questions.
Sep
24
comment Error using Nsolve with system of two equations: “Use Reduce”
@DanielLichtblau thanks! I actually did not notice that NSolve accepts ranges, now it works much better. Updated answer.
Sep
24
comment Error using Nsolve with system of two equations: “Use Reduce”
I tried using Ersek RootSearch, which is supposed to be able to find roots in given range, but on V 10.01 something changed. Now I get No more memory available. Mathematica kernel has shut down. Try quitting other applications and then retry. This package looks like it is no longer maintained. library.wolfram.com/infocenter/MathSource/4482 It worked ok on version 9.01
Sep
24
comment Numerical Error with Matrix operations
try Chop[ret]
Sep
24
comment Manipulating parameters in a complex algorithm
To use second argument of dynamics, yes, you create each control using direct Dynamic syntax. For example, for the slider, you use Manipulator etc.. Then add the specific logic right there in the second argument as pure function. This way, the second argument acts like the callback. Much easier to manage. here is an example mathematica.stackexchange.com/questions/42796/… I do all my demos using this method now. I find this method easier to work with.
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.