# All Questions

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### Problems in getting derivatives [on hold]

i have a problem in getting partial derivative of dtest[a,b,c,d]/da Let me post my real code, ...
64 views

### Why are my associations not consistantly followed? [on hold]

I'm working on a code that automatically reorders the words of a phrase. I'm getting some inconsistencies with the word "glass". EDIT: Sorry for not simplifying the code to a basic example. Here's a ...
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### Plot a cone and a cylinder [on hold]

I have to plot 0=x^2-2y+y^2 and z=sqrt(x^2+y^2) for a class project but Mathematica does not accept raw input, any ideas? I have tried with "cylinder" in the functions but it does not work.
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I am trying to perform numerically the following integral $$\int_0^8\text{d}x\,\text{Re}\left[\frac{e^{-\frac{a^2}{2}-\frac{x^2}{2}} x^4 \sin (b x)\left(e^{-i c x} \text{erfc}\left(\frac{-c +i x ... 0answers 21 views ### How does d/dx (ln(1/x) + c) = d/dx (c - ln(x))? [migrated] I have to find the derivative of the following expression ln(1/x) + c it appears the answer is -1/x however i am told it can ... 1answer 40 views ### Why does the following integral generate an error message for Delete::partw and IntegrateImproperDumptmp The following integral generates a couple of errors that I'm not sure what they mean or how to prevent them ... 0answers 36 views ### Curve moving on the torus [duplicate] I'm trying to do parametric curve moving on the torus. Already have created sample torus : ... 1answer 41 views ### What options for project development exist if the Cloud and Mathematica Online cannot be used Due to contractual obligations to protect IP and client information, we unfortunately, cannot use Cloud or Mathematica Online for development in the development of our projects. We are further ... 0answers 51 views ### Mathematica 10 cannot use EulerMatrix? [on hold] I am using Mathematica 10 on Linux 64-bit and the function EulerMatrix does not work. Is it related with an unloaded package or something? Does every copy of ... 1answer 57 views ### moving of a material point on the surface - paraboloid spiral I have to do project on my studies. I wanna place spiral in this shape. I'm stuck on this point: I have these details: z=4x^2+2y^2 spiral w= (0,0,0) spiral in up Do you have any ideas? Every ... 0answers 84 views ### How to use Mathematica to help me get highest score in every layout? [on hold] The game is hitting the headline in these day and everyone can click this link to play it.The game have a very simple rule like following: Game Rule It will give you a initial layout when you click ... 0answers 42 views ### Solving ode which solution oscillate violently This is a ordinary differential equation: y[x]/(-1 + x^4)^2 - ((1 + 2 x^2 + 3 x^4 - 2 x^6) Derivative[1][y][x])/(x - x^5) + Derivative[2][y][x] == 0 I want to ... 1answer 34 views ### Export of all notebook files as text files I want to export all my notebook files located in a root directory as text files. Below is a simple code that I use. Ho can I export "only" the necessary text content of each notebook file? ... 0answers 27 views ### Solving equations but cannot define argument [on hold] Hi everyone I am new to mathematica and I really need help now. The question is like this: I defined a function H(e1,e2) and I want to solve PDEs like ... 0answers 15 views ### How to change the default stylesheet? How to change \textbf{default}  output font color in Mathematica? for instance : how to set following style as default And how to set the default magnification to 200% instead 100% 2answers 41 views ### expressing a rising factorial as a polynomial I have an equation in x as follows: f(x)=\prod_{j=0}^{k}(j+x)=x.(1+x).(2+x)\cdots.(k+x) I want to express this as a polynomial in x, i.e., as a_0x^0+a_1x^1+\cdots+a_kx^k I tried doing the ... 0answers 24 views ### How to apply Image3D dynamically [duplicate] I have a 3D image which is made up of a number of 2D slices. I want to select mophological components dynamically by clicking on them as done here for each slice. Then form a 3D image consisting of ... 1answer 40 views ### How to list all functions in a package? [duplicate] I got a package which can be loaded in MMA. The manual for the package does not give demonstrations of all functions/commands. Hoe can i find all the commands in the package? 0answers 77 views ### Bifurcation diagram for delayed dynamical system [on hold] The delayed dynamical system describe as \dot{x}(t)=y(t)-ax^3(t)+bx^2(t)-z(t-\tau)+I \\ \dot{y}(t)=c-dx^2(t)-y(t)\\ \dot{z}(t)=r[s(x(t)-e)-z(t)] where a=1.0; b=3.0; c=1.0; d=5.0; r=0.006; s=4.0; ... 3answers 279 views ### Box plot combined with histogram and normal curve Please forgive me if this is a relatively simple thing to do, but I'm relatively new to Mathematica and I've only recently started using it to visualise some statistics for my PhD work (I'm a linguist ... 0answers 25 views ### Mathematica Serious Startup Error [on hold] I am getting "Low-level WSTP error: Unknown internal error" during Mathematica 9.0-10.4.1 (tested with 9.0, 10.0, 10.1 and 10.4.1 fresh install) start-up on some specific Linux machine (x86_64, ... 1answer 198 views ### Make a fractal-like dot animation How to make an animation of following fractal-like gif by using Mathematica? 4answers 437 views ### How to simplify block of multiple repetitive If statements? I'm building a boardgame...game in Mathematica. I have the board state represented as a matrix. It's a two player game, and each player (let's call them A & B) only has one type of piece or ... 2answers 81 views ### Jump boundary conditions I'm having the following issue that can not find a solution , by using this boundary condition ... 1answer 121 views ### Strange DiracDelta integration results in 10.4.1 Integrate[DiracDelta[s (x - c)] x, {x, -Infinity, Infinity}, Assumptions -> {s > 0, c > 0}] gives me c/s in ... 4answers 120 views ### Find the length of the intersection of two lists including duplicates I have 2 Lists. The first one includes all the numbers from 1 to 10. listA={1,2,3,4,5,6,7,8,9,10} The second includes ... 1answer 26 views ### How is Attributes protected and yet can still be set? The Attributes function itself has the attributes: Attributes[Attributes] ... 0answers 27 views ### Reading a set of files in Mathematica in Parallel [on hold] I have a number of very large files (each one of them containing a single list) that I want to import in Mathematica. Reading these files on a single core takes a couple of minutes. Since I run my ... 0answers 72 views ### How to “INJECT” with holding Evaluation, specifically into a WhenEvent I am importing a set of differential and stochastic equations from an external package, and want to use Mathematica to analyse this. I am struggling building the set of equations that I can use with ... 1answer 44 views ### Manipulate a plot with display of a condition This is a how to question --- the example is without importance. I want to manipulate the plot of say a x^2 + b y^2 for (a,b) belonging to a specific set, but a + b > 0. Is it possible to make ... 0answers 14 views ### ArrayPlot arguments [on hold] ArrayPlot[initLat, ColorRules -> {1 -> White, -1 -> Black}, Mesh -> True, ImageSize -> Small] ArrayPlot::argt: ArrayPlot called with 3 arguments; 0 or 1 arguments are expected. Thanks! 0answers 31 views ### Pade approximants for Taylor series using mathematica [on hold] fluid-dynamics In running Pade Approximants for taylor series to rationalize using Mathematica for higher degrees, the program gets hanged. What can be the reason ? 0answers 29 views ### Pass List / Vector argument through NDSolve to a function I am trying to pass vector or list as argument to the function from NDsolve.And I am getting these error. Also I am pretty new to stack overflow. Apology if this a possible duplicate. Here is my code. ... 1answer 55 views ### “Most compatible vector representation” When saving a plot through right click ► Save Graphic As…, Mathematica lets me choose several options, including separate vector representations for areas with ... 0answers 35 views ### Periodic boundary condition trick I'm plotting a curve on a compact space which is having periodic boundaries on the left and right parts. Currently, the code I'm using is working great, but I'm wondering if there's a simpler and ... 3answers 133 views +200 ### How to describe the convex hull of a set of points as an implicit region for optimization? In Mathematica you can create out of a set of points in 2D and 3D the convex hull and use it as a region for optimization problem, e.g., ... 1answer 45 views ### Need help extracting data I'm a teacher on a 20,000/year salary so I'm using Wolfram Programming Lab online to experiment with Mathematica scripts to save money (although I'm hoping to get a raspberry pi as a birthday present ... 1answer 33 views ### portions of plot missing for a relatively simple function I am trying to produce a graph of the linear dynamic system response to a step input. The code is as follows: ... 1answer 42 views ### Metric Simplify & grouping I'm changing a basis from one metric to another. When simplifying the result Mathematica doesn't seem to grasp all the possible simplification: ... 0answers 25 views ### Is there a way to save the output from integrate as a function? [on hold] Is there a way I can save the result of my integration as a function? I would like to be able to assign the result of this integration to a function which accepts ... 1answer 47 views ### FunctionInterpolation on a 2D function does not match original function when plotted together I met with a problem when trying to find the interpolation function of a 2 variable function. The function is like below (already simplified for brevity): ... 0answers 103 views ### Is there an internal logic behind short form symbols, such as @ (Prefix), @@ (Apply), /@ (Map), /. (ReplaceAll) [on hold] To me, function names (such as Apply and Map) seem more intuitive than their symbols (e.g. ... 1answer 121 views ### Map vs listable [duplicate] What's the difference between setting a function's attribute as Listable and using Map? I understand that ... 2answers 77 views ### Free-fall air resistance problem I´m working on a free fall problem and I got an equation with variable k when the situation has air resistance. Then I compared with no air resistance equation (-4.9, considering t variable). So, ... 1answer 69 views ### How can I identify which solution triggered the WhenEvent? I am using NDSolve for problems like this: ... 1answer 81 views ### Drawing spheres with texts on top of each other without overlapping [on hold] I want to use Graphics3D to draw a sphere with a text on it. Then, I'd like to draw another sphere (with a different text on it) on top of the first one. This is the code I'm using ... 1answer 48 views ### Subscripted variables give errors in Module expression [on hold] I have following problem. I want the R not to calculate before the integration but substitute later as a function of z. My Mathematica codes look like: Codes like big, (sorry) but most of them ... 0answers 59 views ### Ramanujan's asymptotic formula for p(n) The following expression is the exact formula of partition function. Ramanujan's asymptotic formula for p(n) is following$$p(n)\sim\frac{1}{4n \sqrt{3}}e^{\pi \sqrt{2n/3}} Can I use ...
I have the following MMA code. Note that the function I declared at the very beginning is the PDF of square of a Nakagami Distributed random variable. With $m=1$ and $P=1$, $f(h)$ becomes Exponential ...
I have the following data for $x$ and $y$ axis, which I am reading from an Excel file by using the Import command and plotting by using the ...