Mathematica Definition and 1000 Threads

  1. A

    Explanations On Entering Various Equations Into Mathematica?

    I've had Mathematica for a long time, but up until now, I just used to use the free-form input. I'm trying to learn the language so that I'm able to do more with the software. However, the information I gather from the Wolfram site is worthless for a lot of things, as I don't understand what...
  2. A

    Mathematica 3D Graphing (3D Plot) Issue

    I'm trying to graph two equations to compare the two visually. For some reason, one of them isn't showing up, even though I'm in a range to where it should be. See the screenshot below. The "3x - y = 4" is graphing fine, but for some reason, "x + y + z = 5" isn't showing up. At first, I...
  3. D

    Mathematica Solving a complicated equation for approximate analytical Solution using Mathematica

    Hello there, I am trying to solve the Following equation for r, $$2 a Q^4+5 r^4 \left(3 c (\omega +1) r^{1-3 \omega }-2 r (r-3 M)-4 Q^2\right)=0$$ Clearly this is unsolvable. But if we substitute a=0 and c=0 we get one of the solution, ##r=\frac{1}{2} \left(\sqrt{9 M^2-8 Q^2}+3 M\right)##. Can I...
  4. A

    Mathematica Why Is Mathematica Not Graphing This 3d Graph Correctly?

    As you can see from the image here, when I graph the 2d graph of y = 5sin(1/x), it comes out like I'd expect. However, when I graph it in a 3d graph, it doesn't look right at all. Can someone tell me why it isn't displaying right, or is it and I'm just missing something when I add the z axis?
  5. Y

    Mathematica table integration error

    I am calculating the temperature distribution and utilizing the obtained results to calculate the current distribution. In order to do this , I employ a table in which I stock all the current distribution for each value of radius . Subsequently, I aim to identify the radius corresponding to a...
  6. Y

    Trouble with using the command WhenEvent in Mathematica

    Hello, I'm trying to solve a heat differential equation to obtain the temperature distribution as a function of R. Since I have the coefficients of electrical and thermal conductivity that start from the temperature of 6500 K, I want the solution to stop when T reaches 6500. I'm using the...
  7. Y

    Mathematica Mathematica Interpolation function error

    Hello everyone, I am relatively new to Mathematica, and I am encountering an issue when trying to interpolate numerical data imported from an Excel file. Here are the steps I've taken: I imported the numerical data from an Excel file into Mathematica. I attempted to interpolate the data using...
  8. L

    Show that these equations are linearly dependent using Mathematica

    TL;DR Summary: solve linear systems of equations Hi, I am supposed to solve the following problem with Mathematica This is the tutorial we received on how to solve linear systems with Mathematica: I then tried the whole thing for the task, but unfortunately Mathematica doesn't give me any...
  9. T

    MATLAB Matlab's numeric solution to det of Matrix is incorrect

    Hello everyone, I have an equation derived as the det of a matrix, which I have solved in Mathematica 11 with Findroot and verified with the respective PhD Thesis' data. However, I now try to get more accustomed to Matlab (R2017b) and hence I tried to reproduce the problem and find its solution...
  10. L

    Mathematica Problems solving this differential equation for a Pendulum with Mathematica

    Hi, unfortunately, I have problems that Mathematica does not solve the differential equation. The task is as follows and it is about the task c In the Mathematica Notebook, the following was written for task c "You can use the following two lines of code to produce the solutions of the...
  11. L

    Mathematica How do you calculate determinants and eigenvalues in Mathematica?

    Hi, In my linear algebra homework, there is a bonus assignment where we are supposed to use Mathematica to calculate matrices and their determinants etc. here is the assignment. Unfortunately, I am a complete newbie when it comes to Mathematica, this is the first time I have worked with...
  12. V

    Mathematica Neural networks in Wolfram Mathematica

    Hello, I have a question about the use of functions and overall creation of neural networks in the Wolfram Mathematica (WM) program. I wonder if it is realistic to make meaningful neural networks usable at least partially for scientific research in WM? By scientific research, I do not mean the...
  13. Leo Liu

    Mathematica [Mathematica] How to use for loop to process a list of data

    Hi. I am writing a program in Mathematica that reads a xsl file from excel, then processes it by solving an equation, and lastly turns the processed data into a list for exporting. Context: Finding the maximum speed of a model plane at different altitudes (density). Screenshots of the code and...
  14. H

    Mathematica Find all values of E for a transcendental equation

    Hi, I'm trying to solve a transcendental equation. I would like all the values of E that solve this equation. ##k = -l \cdot Cot(la)## However, using Nsolve or FindRoot, they give me a precision error. Hence, I'm trying this form. ##\sqrt{-e /(e+v)} = -Cot(la)## FindRoot only give me an...
  15. T

    How can I rederive this Mathematica result for a complex equation?

    Hey all, I am trying to solve the following equation: $$\left(k-i\frac{m_{1}}{v}\right)^{-1}\Bigg(-i\frac{x}{v}-\frac{\sqrt{-x^2+m_{1}^2+k^2v^2}}{v}\Bigg) = \left(k+i\frac{m_{2}}{v}\right)^{-1}\Bigg(i\frac{x}{v}+\frac{\sqrt{-x^2+m_{2}^2+k^2v^2}}{v}\Bigg)$$ for ##x## and we can assume...
  16. K

    Conservation of probability issue when solving ODE in Mathematica

    I am trying to solve this two level (Schrodinger) equation as a function of time:$$i\begin{pmatrix} \dot{x}\\ \dot{y} \end{pmatrix} = \begin{pmatrix} 0 & iW+dE_0sin(\omega t)\\ -iW+dE_0sin(\omega t) & \Delta \end{pmatrix}\begin{pmatrix} x\\ y \end{pmatrix}$$ (I can go into more details about...
  17. A

    Philosophiae Naturalis Principia Mathematica

    Summary: Why did Newton call his book Philosophiae Naturalis Principia Mathematica and not Philosophiae Naturae Principia Mathematica? Why did Newton call his book Philosophiae Naturalis Principia Mathematica and not Philosophiae Naturae Principia Mathematica?
  18. Sciencemaster

    I Calculate Gaussian Curvature from 4D Metric Tensor

    I've been trying to find a way to calculate Gaussian curvature from a 4D metric tensor. I found a program that does this in Mathematica using the Brioschi formula. However, this only seems to work for a 2D metric or formula (I would need to use something with more dimensions). I've found...
  19. Keysa

    How to find the positive maximum value of a function

    This is the code that i wrote Clear["Global`*"] Z = 500; W = 100000; G = 250; H = 100; K = 0.5; T = 30; L = 4000; P = 5; S = 2.5; Y = 1; A = 0.1; V = 2.5; J = 8000; f[x_] := 1/ x {(J*Z*x*(2*Y - x))/( 2*Y) - ((W + T*G) + ((L + T*P)*2*Z*Y*(1 - ((Y - x)/Y)^1.5))/ 3 + (H + T*S +...
  20. T

    Mathematica Mathematica Eigensystem Calculation Taking Too Long

    Hey all, I am currently trying to find the Eigensystem of the following 5x5 matrix in Mathematica. Unfortunately, doing so takes an insanely long time (I cannot even call Eigensystem[p][[1,1]] in a reasonable amount of time). Does anyone have any advice? Also I cannot simply redefine new...
  21. MarkTheQuark

    Mathematica Plotting a parameter Plane of a spring pendulum in Mathematica

    I'm reading an article about the order-chaos-order sequence of a spring pendulum [Ref 1], as I'm reading it I'm trying to reproduce the graphs and results through Mathematica. However, I am new to this software. I will list below some of the most important equations mentioned in the paper. "In...
  22. P

    Mathematica Mathematica - what is wrong with ImplicitRegion[]

    I'm working the integral $$\displaystyle \int_S z\,dS$$ Where S is the lateral (surface) area of the cylinder y^2+z^2=4 cut off by two planes, x=y-3 and x=6-z. Using the parametrization r(x,\theta)=(x,2\cos(\theta), 2\sin(\theta)) this is pretty straight forward $$\int...
  23. alexmurillo242

    Mathematica Piecewise Time-Dependent Hamiltonian in Mathematica Strategy

    Hi all, I'm doing some light simulations for an experiment I'm going to be running soon. I've ran through the math symbolically on paper but I'm not exactly eager for handling this large of matrices by hand so I'm trying to work through it and see if I can generate a simulated signal to compare...
  24. arjit

    Mathematica Simulating the quantum Zeno effect using Mathematica

    I'm trying to simulate the quantum Zeno effect using Mathematica and I need to apply von Neumann and projection operator on to same density matrix and in a loop one by one, it's basically switching between two evolutions in time., so I need help on how to do it.
  25. M

    Mathematica How to simplify expressions in Mathematica with log and exp in them?

    Hi, This is a pretty simple question, but I am new to Mathematica so I am not sure if I am missing something obvious. Question: How do I make the expression ## e^{log(z)} ## return z? Attempt: I have used all of the following combinations and all of them return ## e^{log(z)}##. Are there any...
  26. M

    Python Import python list from .txt file into Mathematica

    Hi PF! I am trying to import k.txt file into Mathematica as a list of numbers. The k.txt looks like this: [5.315967917338153e-06, -3.204321972222162e-08, 3.6041782425371564e-09, -3.853442465663655e-08, 8.699510604529962e-07, -1.4284341965847237e-08, 2.855341882658808e-09...
  27. M

    Python Use Python to integrate a function constructed in Mathematica

    Hi PF! I followed someone's help on here and have the following code in python that performs monte carlo integration from math import * from random import * def integrate(alpha): # MONTE CARLO INTEGRATION OVER NON-RECTANGULAR DOMAINS def f(pt): # RETURN INTEGRAND AS FUNCTION...
  28. M

    How Can I Get Help with Mathematica Programming?

    I'm a student, I need help with Mathematica
  29. F

    I Infinite Square Well with an Oscillating Wall (Klein-Gordon Equation)

    I am trying to numerically solve (with Mathematica) a relativistic version of infinite square well with an oscillating wall using Klein-Gordon equation. Firstly, I transform my spatial coordinate ## x \to y = \frac{x}{L[t]} ## to make the wall look static (this transformation is used a lot in...
  30. rudransh verma

    Should I Read Newton's Principia Mathematica?

    I was wondering to read this book to get a better understanding of the classical world. I want to know what things are there that I can learn in this book? Is it worth it? Is it tough? Should I read it or it will be covered in undergraduate and graduate level of physics?
  31. Z

    Mathematica Mathematica bug? (Solving PDEs when the initial conditions contain a derivative)

    hello I own mathematica 10.02 it is virtually impossible to solve PDE's ,even with NDSolve,if the initial conditions contain a derivative I write Derivative[1,0] [0,x] == f[x] I mean the first t derivative of u[t,x] for x at t=0 is f[x] I own a book based on Mathematica 10.3 Even if a...
  32. C

    Can I improve the sinc interpolation?

    Hello everyone. I am working with mathematica, where I have developed a two-dimensional shannon interplation, just as can be seen in the slides 15 to 18 of this presentation. The code is as follows: savedX = Table[XposX = mat[[All, 1]]; YposX = mat[[All, 2]]; windXVal = mat[[All, i]]...
  33. J

    MATLAB Conversion from Mathematica to Matlab

    Hello!. I am new to the forum and I am also a newbie to programming. I want to convert a Mathematica code to Matlab, but I don't understand how to translate these lines. This code is Mathematica 5.0. defvar := Module[{a}, Clear[ cN, cNf, ginix ]; Clear[ Nh, Nhf, gini ]; cN =...
  34. Abhisheko07

    Mathematica Mathematica error when solving a DE -- "exceeded RecursionLimit"

    Homework Statement:: I don't know where the mistake is happening. I need to solve the give differential equation in mathematica and have to plot it but i am facing problem in doing so. Can anyone help me in this? Relevant Equations:: I have attached the picture of equation as well as my...
  35. C

    KarhunenLoeveDecomposition function in Mathematica

    Hello everyone. I have a vector, stochasticData.mat, it contains a matrix of size 211302*50, being 211302 measurements of 50 realizations of a stochsatic process. I want to use the Karhunen-Loève expansion and the software Mathematica to calculate the uncorrelated random variables. For that, I...
  36. MNaydenov

    Mathematica Loop integrals using Package-X 2.0 in Wolfram Mathematica

    Hello everyone, I have trouble installing Package-X 2.0 to Wolfram Mathematica. It says that the package should be available at https://packagex.hepforge.org but this page does not open. I tried everything I could to install and load this package but it was all unsuccessful. It seems as the...
  37. Haorong Wu

    Mathematica Looking for packages for tensor calculation in Mathematica

    Hello. I am doing tensor calculation with indices, such as contraction, lowering or raising indices, tensor production, etc. I have tried the Ricci.m from https://sites.math.washington.edu/~lee/Ricci/ However, maybe because the package has not been upgraded for some time, I could not get the...
  38. A

    Mathematica Implementation of tessarines in Mathematica

    Hello, guys! I just wanted to share that there is a way to easily implement split-complex numbers (and tessarines) in Mathematica. $Pre = If[FreeQ[#, J], #, Module[{tmp}, tmp = Evaluate[ MatrixFunction[Function[J, #], {{0, 1}, {1, 0}}]] // FullSimplify...
  39. M

    Build a surface normal vector (I use Mathematica)

    Not HW, but seems to fit here. I compute $$n.S = \frac{(-1+\cos(c s))}{c^2} \sin(c s) \neq 0$$ I use the following in Mathematica: r[s_, \[Alpha]_] := Sin[Cos[\[Alpha]] s]/Cos[\[Alpha]] z[s_, \[Alpha]_] := (1 - Cos[Cos[\[Alpha]] s])/Cos[\[Alpha]] x[s_, \[CurlyPhi]_, \[Alpha]_] := r[s...
  40. S

    Mathematica Tracking dynamic markers across plots (Mathematica)

    Let's say we have a rectangular plot of two curves X(t) and Y(t); and next to it we have a parametric plot of (X(t) , Y(t)). Now we want to add a slider that can control markers on both plots, so that the slider ( = ts) moves two markers X(ts) and Y(ts) across the rectangular plot and at the...
  41. M

    Path Integrals in Wolfram Mathematica

    Hello everyone ! I am new to this site so I 'd better say hello to you all ! I am finishing my BR in physics and part of this ending is to deliver a thesis . Long story short I must compute path-integrals in SU(2) and SU(3) pure yang-mills fields . Problem is that i was never very good with...
  42. S

    Mathematica Fourier Transform Help with Mathematica

    I am attempting to be able to do this problem with the help of Mathematica and Fourier transform. My professor gave us instructions for Fourier Transformation and Inverse Fourier, but I don't believe that my output in Mathematica is correct.
  43. S

    Mathematica Definite integral with some unknown variables

    I am trying to evaluate an integral with unknown variables ##a, b, c## in Mathematica, but I am not sure why it takes so long for it to give an output, so I just decided to cancel the running. The integral is given by, ##\int_0^1 dy \frac{ y^2 (1 - b^3 y^3)^{1/2} }{ (1 - a^4 c^2 y^4)^{1/2} }##
  44. JD_PM

    Mathematica Learning how to compute Christoffel symbols using Mathematica

    I am using the code provided by Artes here, but I am missing something. The Chrisfoffel-symbol formula is $$\Gamma^{\mu}_{\phantom{\mu}\nu\sigma}=\frac{1}{2}g^{\mu\alpha}\left\{\frac{\partial g_{\alpha\nu}}{\partial x^{\sigma}}+\frac{\partial g_{\alpha\sigma}}{\partial x^{\nu}}-\frac{\partial...
  45. S

    Mathematica Inc, Dec buttons while "Manipulating" an array (Mathematica)

    This code takes the coeffeicient array c0 from the first line and does the Manipulate thing, putting in as many sliders as the length of c0. Problem is that I couldn't find a way to enable the increment and decrement buttons that you usually get for the sliders, even though I have put in the...
  46. Ishika_96_sparkles

    Mathematica Want to learn Mathematica programming

    Could anybody already working in Mathematica guide me? I want to learn how to program for physics, to be able to simple models, make graphs for equations, and finally able to solve problems especially Quantum mechanics. Where should i begin? I have never used such 'software?/language?' before. I...
  47. S

    Mathematica Mathematica - Manipulate slider - fine adjusting with [ALT] key

    It says here ... https://reference.wolfram.com/language/tutorial/IntroductionToManipulate.html#498667553 [section : Initial Values and Labels] ...that you can fine-tune a "Manipulate" slider by holding down the ALT key while you drag the handle. This is indeed the case, but unfortunately, the...
  48. Luke Tan

    Mathematica Mathematica Graph Plotting for Scientific Papers

    Hey guys, so recently I've been trying to use mathematica to plot graphs for my scientific papers, and I've been starting to wonder - what plot options do you guys use? How do you plot your graphs in mathematica such that they look presentable in a scientific paper?
  49. N

    Mathematica How to define such a simple function in Mathematica

    A very simple question but I can't find an answer. I have an expression which depends on two integers, n,d. Now, I want this expression to be a) 1 when d=n=0, b) some expression (that I won't write here) when both d and n are >0 c) zero when wither d or n negative. At first I defined the...
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