# All Questions

59,967 questions
32 views

### Save nested Solve results into variables (edited)

I have some solve results stored in the ptes variable: ...
54 views

### Differential equation with polynomial powers

I'm trying to solve the following equation: Sin[f t] == y[t] + y[t]^3 + y'[t] + (y'[t])^3 Where f is a constant, the ...
55 views

### 3D rigid body physics engine

Is there a package in Mathematica that will allow me to simulate collisions of 3d rigid bodies? If not, what known libraries could I use and how? For example, one problem I want to simulate is a ...
43 views

### Recursive Function in Multiple Variables

I can define a recursive function in one variable, e.g. defining the factorial function $f(n)= n!$ using Mathematica. But how do you do this for a function which depends not only on $n$ but on $x$ and ...
26 views

### Christoffel symbols:The expression can't be used as part specification error

I'm a new user. I want to ask that what's the problem of my process? Can anybody teach me? I'm trying to calculate Christoffel symbols. ...
162 views

### Mathematica 12 default graphic opacity is 0, i.e. invisible

I just upgraded to Mathematica 12 and am trying to draw a line in a graphic and am finding that the default opacity for a new notebook is 0, making them invisible. I can correct this for lines but ...
164 views

### Mathematica 12, supported GPUs

It seems that Mathematica 12 doesn't support NVidia 2xxx (i.e 2080), 16xx or 1xxx series. Could it be that the CUDA section has not yet been rewritten for 12? https://reference.wolfram.com/language/...
22 views

### Getting values of EllipticK with arguments that are very near 1

I need to evaluate EllipticK[m] very close to 1. However, when I get too close to 1 the function defaults to the exact solution for 1 , which is ...
29 views

### Verifying which 5-strings form valid words

words = getWordsFromPi[200]; For[i = 0, i < Length[words], i++, if[DictionaryWordQ[StringJoin[words[[i]]], Insert[list, words[[i]]]]]] ...
46 views

### Using ± to express two roots of a quadratic giving trouble [on hold]

the below equation are the roots of a quadratic I'm examining: $$A=\frac{r\pm\sqrt{r^{2}-\frac{4r(1+\alpha)(1-\alpha)T}{A^{s}}}}{{2r(1+\alpha)}{A^{s}}}$$ However, when I ...
38 views

### Matrics manipulations

this is a basic question in Mathematica, I hope to get help to resolve it, How I can extract elements from matrics for example I have ...
55 views

### Configuration of PlotLayout as “Row”/“Column”

A long awaited feature has finally been implemented in Mathematica v12: the multi-panel plots via PlotLayout! Demos are here: http://www.wolfram.com/language/12/...
49 views

### How can I animate multiple objects at once?

I'm new to Mathematica and I'm trying to do this project where I have to animate multiple circles. I have 4 circles, each with x = 1, 2, 3, 4 , respectively. Each ...
30 views

### Reversing axis prevents formatting of that axis

I'm looking to make a graph with the x-axis reversed and a frame and tick marks that are thicker than default. However, the x-axis tick marks do not maintain the specified thickness once I reverse the ...
41 views

### Mathmatica solve one variable but no solution [on hold]

solve[bx( 1 + ac ((x^(-0.5) - 1)/((1 - c)c^(-0.5) + c))) - d == 0, constant -> {a, b, c, d}, x] for some reason I don't get any solution? Please help. Thanks so much!!!
22 views

### Discontinuities in taking the roots of a complex function

I have the following functions e1, e2, and e3 which consists of the functions ...
33 views

### How can I select a solution that satisfies a particular set of conditions?

I am solving a Kuhn-Tucker problem and the list of potential solutions is vast. I've been searching on these forums for a while and still cannot figure out a good way to select particular solutions ...
37 views

### Axes behind plot lines

If I do a plot and want both the horizontal axis and a frame I can do this: ...
40 views

### Generate a uniform distribution over an $n$-simplex employing quasi-random low-discrepancy points

This post is intended in a similar direction to an earlier one Can I use Compile to speed up InverseCDF? . I now wish to generate uniform points in an $n$-simplex (specifically $n=8$), making use of ...
34 views

### Creating a directed random graph with negative assortativity [on hold]

How could I create a random graph that will have a negative assortativity? A graph where nodes with small degree will tend to connect to nodes with a high degree and vice-versa. Any ideas are much ...
59 views

### Problem with fit

I am trying to find a proper matching function for the following data set: ...
33 views

### Parallelizing nested for loops

I'm currently computing nested for loops. I count up a few counting variables and compute a value for each set of counting variables, then that value is added to an array. It is a way of adding up ...
35 views

### Creating a prediction/distribution based on several years of data

So I have several years of data from a survey. For each year I've used FindDistribution and Predict to see if I can fit the data. Here's one example Where I used FindDistribution to get ...
24 views

### Speeding up solving many coupled non-linear differential equations

I am currently working on a project that involves solving many coupled non-linear ODEs$^*$ I am using NDSolveValue and the time it takes to solve everything is (understandably) slow. But I was ...
22 views

### Table with two functions to output matrix with values

So I have a wing modeled as an .STL and I am analyzing its structure so I need its cross sectional area and moment of inertia at points along its span. I do this by moving an infinite plane across the ...
41 views

### How to solve an ODE system with Mathematica?

I I'm trying to solve this problem with mathematica but the code keeps giving me an error.
36 views

After saving (with QGis) the part of the map I´m interested in for a local visualization, I have the .zip file where you can see 5 files. I load the map in Mathematica with ...
36 views

### Using Interpolating Function [duplicate]

I'm a bit of a noob with mathematica. I'm having a problem trying to use values from my solution. I've used ND solve to integrate ODEs. I have ...
399 views

### How to prevent mathematica rounding extremely small numbers to zero?

I have a function that, while the maths itself is unimportant, at certain values it results in a very large number multiplying a very small number. E.g. 10^450000 * 10^-449998. As you can see, this ...
35 views

### Solve: line and rectangle intersections

I have been trying to find the intersections between a rectangle and a line, following the example given in the Solve function: ...
27 views

### Trying to solve recursion using rsolve

I'm new to Mathematica, and I'm trying to use RSolve to solve an equation I couldn't do in Matlab, as I got errors there too. This is the system I'm trying to solve:...
19 views

### How to separate nested subexpressions to list?

I have an expression like this: 3*Subscript[v, 0]^3*Subscript[v, 1]^8*Subscript[v, 2]^7*Subscript[v, 3]^2 I would like to extract the exponents and put them into ...
18 views

### Use ChoiceDialog to assign value to a variable within a function

This may be a routine answer that I have overlooked, but I am stumped... If I want to write a function using ChoiceDialog, how can I use what ChoiceDialog returns (true or false) to either set a ...
44 views

### Meshing control of NDEigensystem

I have to solve an Eigenvalue problem originating from the Electrodynamics. It is a 2-D problem with a rectangular region. More specifically, there is a hole on a rectangle made by magnetic material. ...
22 views

### Is it possible to get the required mathematica code from wolfram alpha input?

It is very easy to get an out put in wolfram alpha if the input is very complicated and mathematica coding giving some problem. So is it possible to convert an wolfram alpha input to a standard ...
68 views

### Problem with InverseFourier of a 2d FFT of a non-squared image

I have the following 8bit grey scale image: The 2d FFT of this image, showing the color coded Abs[fft] values, is: The code to obtain the FFT image is: ...
27 views

### Placing two 3D graphics below each other without blank spaces

I have a simple placement problem related with the function GraphicsColumn. I have to draw a simple figure with orbitals using Mathematica, that highlights two similar cases, one below the other. The ...
24 views

### Finding the positions of minima for a function with algebraic constants

I have a function of several variables: inverse[Qx_, Qy_]:= T - 2 J + 4 J1 Cos[(Qx + Qy)/2 a] Cos[(Qx - Qy)/2 a] - 2 J2 Cos[(Qx - Qy) a] + 2 J3 Cos[(Qx + Qy) a] ...
22 views

### Maximum likelihood method computational details

I am currently using the command FindDistributionParameters to estimate the parameters of a StableDistribution via Maximum Likelihood using Mathematica 11. As there are different MLE methods for ...
65 views

### How to fit my data to an ode

Here is system of ODEs and data, where I am trying to use the real data to estimate some governing parameters. ...
43 views

### Errors in Gaussian fitting curve

I fitted simulation data with Gaussian fitting curve, ...
17 views

### Unclear behaviour of Position, lists and functions in general [duplicate]

apologies for the title, but I have such a confusion about my question that I haven't been able to formalise a clear title. My question arise from the "discrepancy" between the results of the ...
115 views

### Meaning of InterpolationOrder -> All for multidimensional interpolation

What specific method does Interpolation use for unstructured multi-dimensional data when we set InterpolationOrder -> All? ...
44 views

### How to uncompress zip file fast with Mathematica?

What is the fastest possibilty to uncompress zip files with the following content? It containes numbered ".png" files, corresponding ".header" files (theses are text files) and a file called "...
44 views

### How to maintain the number form in the next operation?

I am dealing with coordinates of atoms, in which I need to control the number of decimals. Take two sets of coordinates as an example: ...
77 views

### Fit Markov Chain

Assume a simple Markov Chain with the transition matrix ...
30 views

### How to plot two functions together when one of them needs to be a series of dots, with common labels and colors?

I have two functions that I want to plot together. I want to plot the non-linear and the linear (NL and L in my code) functions together, but I wish that the NL function is plotted as a series of dots ...
31 views

### How to create a list of element-wise pairs from two lists? [duplicate]

As an example, given A = {a, b, c} B = {x, y, z} How do I create? C = {{a, x}, {b, y}, {c, z}}