All Questions

I have a $4\times4$ matrix A=\begin{pmatrix} 0.16 (\cos (\text{kx})+2) & 0.55 \cos \left(\frac{\text{kx}}{2}\right)+(0.\, +0.76 i) \sin \left(\frac{\text{kx}}{2}\right) & 0.55 \cos \left(\...

I really love the flexibility of Mathematica: there are several ways to perform one task. However, to get the performance of the intense numeric calculation, it can ...

I can't find any explanation about the details of the real computation, please anybody knows? ...

I would like to shade area of region as a function of angle using PolarPlot. Here is my attempt. ...

I have attempted to exercise a non-linear model fit to my data, dadtAbs, and got the following puzzle ...

I have attempted to exercise a non-linear model fit to my data, dadtAbs, and got the following puzzle ...

I have a image which I want to fit 2d Gaussian function with that. I used the below codes but the output figure doesn't look alright. I extracted the mean and covariance values in x and y direction.I ...

The following code sort the list li in a such way that consecutive terms $t_n,t_{n+1}$ are of the from ...{x_,y_}, {y_,z_}.... i....

Grandson and I are working on the Calculus of Polar Coordinates, specifically, finding the area enclosed by a polar plot. We can find the area; however, we cannot seem to find anything in the ...

When trying to solve the differential equation radialEqdouble[k_] = f''[u] + k*u^2*f[u] - u^4*f[u] where k is a constant, I am able to produce a plot consistent ...

I am playing with Natural language programming in Mathematica, and can't figure out how to extract the entity classes (i.e. male, female) for the following example text: "This was a pleasant ...

How to fix a ParametricNDSolveValue? - "ParametricNDSolveValue::ndnum: Encountered non-numerical value for a derivative at t == 0." I have tried ...

I have two criteria for the domain of $n\in\mathbb{N}$: For all even $n$, I want to use the constant function $f(n)=5$ For odd $n$, I want to use the function $g(n)=9 \sin \left(\frac{\pi n^2}{5}\...

I am trying to solve an optimization problem with several parameters and here is my code: ...

If I have three criteria for the domain of $m\in\{1,2,3,4,5,6,...,22\}$ as $$f(m)= \cos \left(\frac{\pi ^5 m}{4}\right)\quad for \quad m=3,6,12,15,21$$ $$g(m)=\frac{1}{\sin \left(\frac{\pi m}{3}\...

This may be a very simple question: how can I substitute out a term involving a derivative in Mathematica? I have the following derivative: ...

In general, to define a function, we often use f[x_]. Another way is to use pure function (full form and shorthand). I want to test the performance of these ...

I try to generate a list of first degree exponential equations in the real ones and that the solution is in logarithm in base 10 as simplified as possible, for example x= log(7) , where log is in base ...

According to the documentation Abs[z] gives the absolute value of the real or complex number z and is also known as the modulus. As far as I'm aware for any definition of the absolute value, norm or ...

Why number sign "#" (known as hashtag symbol on social media) or at sign "@" are not consistent with the ...

Consider a function derivative[x_]:=D[Sin[x],x] When calling it with some argument, like derivative[2], instead of $\cos(x)$ it gives me $\partial_{2}\sin(2)$. Is ...

I would like to solve the following: given $t\mapsto\sigma(t)$ and $E>0$, $\sigma_y>0$, find $\epsilon$ such that: $$\left\lbrace\begin{array}{l}g(t,\epsilon)\geq 0,\\ \phi(t,\epsilon,\epsilon')\...

Using Wolframalpha or inline free format you can obtain a nice representation of a sum of vectors. An example is shown below. Whish is the hidden code? (or a code that make the same representation). ...

I try to solve this PDE ...

I'm quite new to mathematica, so apologies if the question it soo trivial. I'm trying to symbolically solve an equation for R, and would like at the same time to mix in a second equation. What I've ...

How can I ask Mathematica to range all the natural numbers $1<n<500$ which are not multiples of 5? I mean I need to get $$\{1,2,3,4,6,7,8,9,11,12,13,14,16,...,499\}$$

Are CriterionFunction, Method and DistanceFunction options orthogonal? or does any of them sets another. Mathematica Help says that CriterionFunction selects a method, so it does not make sense to set ...

I am slowly learning how to use Feyncalc, and I have a quick question. I have a third rank tensor B[mu,nu,tao] and I also have a four-vector FV[W,mu]. I would like to contract the first two indices ...

I have a matrix polynomial P(s) and the Jordan blocks of P(s) corresponding to every eigenvalue sj (j=1,...,k). How can the Jordan Canonical Form be generated, i.e. the block diagonal matrix which has ...

I wrote a code which gives me a list which has one coordinate point (for example {{10,11}}) I was wondering how i can only take the y part (which is 11) I tried using: ...

I have define the following functions: w[k_] := k*0.8 + (1 - k)*0.3 b[k_] := 0.3*Sqrt[k] and I want to solve the following system of equations ...

Is it possible to automatically label boundaries of a RegionPlot in a similar style to PlotLabels by the equality that describes ...

I have a Graph3D object representing a 3D lattice path ...

Say I have an expression that is a polynomial in a variable, for example in the variable $x$, in which terms appear for which the exponent of $x$ also includes variables. For example: ...

Lets define the functions osc = E^(-((I (4 x^2 - 4 y^2))/(4 \[Pi]))); const = 1/4 Sech[1/2 (-x - y)]^2 Sech[(x - y)/2]^2 Sinh[x]^2; the ...

I have a function, not very complicated, somewhat similar to an infinite, converging Geometric Progression. Here is my function: Y = n^t / t!. Nonlinear Model Fit works not at all with this expression....

I'm trying to parse a LaTeX representation of a Desmos calculator (like this one) via Mathematica. Desmos exposes a JSON representation of its calculators, including a LaTeX representation of ...

To get the color at a 2D point in Graphics you can Rasterize it and look up the pixel value, but not for ...

I have to form a matrix like this. How ever I can not directly input. I have to form a function and then use the table command. I am stuck. {{2,5,10},{9,12,17},{28,31,36}}

While doing some (symbolic) calculations with Mathematica, I encountered a small problem with the FullSimpilify function that hopefully someone here might explain to me. More specifically, I fear that ...

I want to use a solve statement inside a for sentence to solve a system, not a single equation

How to achieve that Dt[] does not touch certain function compositions, but still applies all the other derivative transformations. Example: ...

I am trying to solve a 3 unknowns 3 equations system. The code does not give any error but gives any output neither. ...

I have a plot that includes a RegionPlot. I want to make a rectangle with the same shading as in the region plot to show as a legend. The dumb way I can think off ...

I have a fairly simple system whose solution involves conditional expressions. The system is ...

So Im trying to model the concentration profile of a diffusing species into a sphere in an acid-base equilibrium system. Although im getting a solution, Its not the values or the trends I expect. Is ...

I am plotting three lists of different size on the same plot. I want the plot to start from zero rather than 1 on the x-axis. In the past, I have used ...

I'm trying to create an animation of derivative. My problem is very simple: a point is hidden behind the x-axis. This is my code: ...

I want to make the Final use fewer mesh lines, the ideal version will look like the second image. Where the triangle shape is more clear and clean. Can anyone give me some advice on how to fix my code?...

I've been working on a project to simulate the movement of a double spherical pendulum through Lagrangian mechanics. I found this link, which has the equations of motion in. I need to solve for the ...