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I'm trying to use the built in Arnoldi method in Mathematica to compute the first 1440 eigenvalues of a large sparse matrix. After importing ...

I have a function called BasicEulerModified, that is fine(I think). However, when I run another cell to generate a list of ordered pairs, I get the Error "Part specification is longer than depth of ...

https://www.wolframalpha.com/input/?i=%28a+and+b+and+c%29+or+%28not+a+and+not+b+and+not+c%29+or+%28not+a+and+b+and+not+c%29+or+%28a+and+not+b+and+not+c%29 How do you plot Venn Diagramm shown in the ...

I have to compute a function "func" with 24 arguments. Unfortunately when I apply the arguments the RAM fills up immediately. I even change the swap size of my Linux system to 100 G. I hope somebody ...

I have gathered some sports data from over 40 different sources. I now need to get all the games to "match up", "grouped", "clustered", or "aligned" so all the information for one game is in one list....

I have a complicated equation in terms of $\omega$ and $\kappa$: ...

I have high ranked polynomials for which I need to find local minima. Each polynomial has an increasing rank and only one minimum that is valid for the purpose. So from the lowest ranked polynomials I ...

Suppose that I have a list of depth $k$, and I want to apply a function $f$ to all elements at level $n$ - e.g. $f,\{\{\{a,b\},\{b,c\}\},\{\{c,d\}\}\},3\mapsto\{\{\{f(a),f(b)\},\{f(b),f(c)\}\},\{\{f(c)...

I have a set of linear equations for 4 quantities which have been both Fourier transformed and Laplace transformed. The system needs to be solved for the quantities and then each of the quantities ...

Say I wish to find the minimum value of the determinant of a symmetric matrix under the condition that the matrix be positive definite. So I attempt: ...

I am trying to understand why FullSimplify[x^a < 1, {0 < x^a < 1}] does not simplify but ...

I have created the matrix m and I am not able to sum all the elements. {1, 2, 3, 4} would give 10 for example. Can anybody help? Best,

If you submit this to WA https://www.wolframalpha.com/input/?i=%28a+and+b+and+c%29+or+%28not+a+and+not+b+and+not+c%29+or+%28not+a+and+b+and+not+c%29+or+%28a+and+not+b+and+not+c%29 and expand the ...

I am using Taylor series to approximate error function on complex domain. For a given $z\in D\subset \mathbf{C}^1$, we know the Taylor series of error function (around point $z_0=0$) is uniformly ...

Given a certain Control object (checkbox, for example) within a Manipulate environment, my goal is to define another control ...

I have a function of one variable $f(x): \mathbb{R}\to \mathbb{C}$ which is very difficult to evaluate. Single evaluations may take hours, and I need to use the function at a large variety of points. ...

I am attempting to run parallel finite element simulations in Mathematica using the AceGen & AceFEM softwares in conjunction with a MATLAB script called from Mathematica. I am able to run some ...

I have written a simulation that solve a pde, I used a method I found on this site to speed up the calculation but it is still slow. Is there any way to speed up the prosses? ...

I have a surface plot, I wanted to fix the axis labels and ticks to this plot, but I am unable to fix this. How to do this, Here is the code I tried. the x-axis limits 1e-3 to 1e12, and Y-axis is also ...

I have this initial conditions ...

Look at the following chunk of code: Assuming[x > 0, Refine@HeavisideTheta[x]] It yields 1. However the same method does ...

Following the problems in my previous question: How to get good images for Graph in Published Notebooks I found a way to fix the aliasing issue, apparently, the ...

I have following statement: EntityValue["Planet", "VelocityAroundSun", {"Date" -> DateObject[{2020, 2, 19}, "Day", "Gregorian", 1.]}] and get the required ...

How to solve a coupled Boltzmann non-linear differential equations that one encounters in cosmology? For example-

I am trying to use xCoba with a diagonal metric depending on an unspecified function f[r], but I get the errors: CTensor::...

Consider a list of lists in this form (with a shape $ m \times n \times 3 $): ...

How do I plot this integral on mathematica? I am trying to do this by hand but want to check on mathematica to see if I am doing it correct.

Disclaimer: I am new to Mathematica and this is my first post here! I am trying to plot EEG data of different intensities of brain waves from an FFT to areas of the brain where they were collected. I ...

I am trying to connect a Raspberry pi front end (notebook) to a remote kernel running Ubuntu with the free Wolfram engine. I have researched this answer but it never worked. Using the code below I ...

How can I ask Mathematica to find all polynomial $ f \! $s such that, for a constant $ k $: $$ f(x) \ f(y) = f(x) + f(y) + f(xy) + k $$ I've solved it on paper and want to check my results. I've ...

Plot3D[{x^(2)+4y^(2)+9z^(2)=1},{x,-5,5},{y,-5,5}] When I plot this it comes up as a plane which I know is incorrect, What is wrong?

How would you plot the definite integral ∫4 dx on interval [a,b] where a=0 and b=4 are the upper and lower bounds on mathemetmatica? The reason why I am asking is because I am practicing graphing ...

How I can wrap the 3D vectors around the sphere surface like this one. My angles are ...

Can you help me to do the fit for the following equations to obtain the values of $a$ and $b$. {20.7 == a + b/(5^4), 28.62 == a + b/(6^4), 32.04 == a + b/(7^4)} ...

I'm taking a class that is based on the Mathematica coding language, and we must do a 6-week final project. I am considering coding a neural network for a simple game like 2048, pacman, snake, etc. ...

For the table x with three lists per row: ...

I have a two column data which is y vs x. I want to linearize the data by this formula 1/(x-b) but I don't know how to determine the b value such that the ln(y) vs 1/(x-b) becomes a linear line. So I ...

I would like to create a cool differential line growth animation based on this great tutorial. The only missing part is the relax node, but I couldn't find any pointers on the web how to implement ...

I have a problem with fitting an exponential function to the data. I used the NonlinearModelFit function to perform the fit. The code plots the fit but not the data and the standard error for the fit ...

I have a frame to label as such: FrameLabel -> {{Style[Row[{"Ln(R)", " (a. u)"}], 18, "TR"], None}, {Style[Row[{"Inverse of T", " (K^-1)"}], 18, "TR"], None}} ...

I am new to Mathematica. I am trying to find out the best-fit values of the parameters appearing in an ODE system of three equations. The three ODE equations are: ...

I have list of rules, something like {f[x,y,z]-> F, g[x,y,z]-> G, D[f[x,y,z],x]-> fx,...} I would like to assign the values to the variables like I ...

I am trying to calculate a system of (almost) linear equations. I have 10 equations and 9 variables (first 10 lines in the Solve function), so it should be possible. ...

I want to define a function in Mathematica where I get all combinations of an expression, e.g., input: {q,p1,p2} Output: ...

I have lots of csv files in a folder. Each file contains a column with date, year and time and the second column values for each time. I would like to import all these files and for each file take a ...

Using the link Definition, it is possible to compute the entropic risk measure as follows: $$ EVaR=\text{inf}_{z>0}\{z^{-1}\ln\left(\frac{M_X(z)}{\alpha}\right)\}, $$ wherein $X$ is a random ...

From the basics of the signal theory the impulse response function (IRF) can be calculate like (L=Laplace transformation): L[x(t)]= X(s) , L[y(t)]= Y(s) and transfer function H(s)= Y(s)/X(s), then IRF ...

I have some simple equations such as ...

How to save ParametricPlot with opacity[0.5] with transparency? When I save the image the transparency is completely lot. in both pdf and eps files. I use The following code for saving my parametric ...

While obtaining the Schwarzschild solution I want to evaluate the Christoffel symbols, Ricci tensor and etc by checking the results with Mathematica. Is there an online source to compute the wished ...