# All Questions

60,839 questions
6 views

### Fourier transform of a 3D list {x,y,value}

I have a list of x and y coordinates and values corresponding to it. (Note: I don't have a function). ...
8 views

### Why unable to verify solution to first order PDE?

This is using V12 on windows. I solved this PDE by hand and wanted to ask Mathematica to verify my solution. But Mathematica solution does not look like mine. And when I tried to verify Mathematica ...
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### Problems drawing geodesics on a torus

I have some problems with this answer geodesics' on torus. I mean the first variant of answer. I'm trying to enter the points u1, u2, v1, v2, but the solution does not output anything, only the ...
22 views

### How to join two matrix with different dimensions

I have two matrices with different dimensions I want to join them together in one matrix. for example, I have two lists of diseases associated with their symptoms in both matrix, what I want is to ...
30 views

### ThermodynamicData error: “Water is not a known entity”

I can not perform calculations with ThermodynamicData. Is there an error in my code?. I have MMA 12.0 Windows 10 ver.1809. ...
31 views

### Why don't these function definitions work?

picked up Mathematica (transitioning from Python) a couple of days ago so forgive me for the newbie question. I'm trying to create a function which takes in a list of numbers and returns a list of the ...
39 views

### Chain rule by Mathematica

Please, how to evaluate dh(g(x))/dg(f(x)) by the following definitions: ...
18 views

### Plotting Evolution of probability with time

I have compiled data about the evolution of a function with time and the data looks something like this. I wanted to plot this data in the form of a density histogram such that every row represents ...
29 views

### How to draw a multi-color USA state map with Geo entities?

Needed to draw a salesman territory map, multicolor like a schoolhouse USA states map, with the Postal Abbreviation location at the state capital. Wished to do it with GeoGraphics and curated ...
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### Finding common terms in an expression to simplify further?

When I write a manuscript which has two columns, usually it's hard for me to fit a big expression into one line. I usually simplify the expression further by manually finding some common terms (...
48 views

### Numerical calculation Mathematica 11.2 / 11.3 / 12 [duplicate]

Please I do not understand why Mathematica 11.2 version evaluates numerically the value below Exp[-800]//N (* 3.667874584178*10^-348 *) while 11.3 and 12 ...
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### Implementing an anti-alliasing filter in Mathematica

I'm experimenting with FFT simulations. I'm generating transient data at the some sampling rate, down-sampling this (mimicking a device's behavior) to 2048 points. Then take the FFT using ...
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### Using CreateDocument in a function

Is it possible to utilize Mathematica's CreateDocument within a function, so that a notebook pops up in the front end? For example, creating a function like: ...
24 views

### Solve a nonlinear eigenvalue problem

I have been trying to solve a nonlinear eigenvalue problem (in the form of an integro-differential equation for $u(x)$ on $x\in[-L,L]$) in MMA, uu^\prime+u^{\prime\prime}+u^{\prime\prime\prime\...
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### Percentile BarChart with different EdgeForms

Is it possible to define different Edgeform's in a in a BarChart with ...
56 views

### Is there an efficient way to fill in the elements of a matrix as m11,m12…etc?

I want to autofill the elements of a matrix (or list) by m11, m12, etc. I am able to autofill using ...
40 views

### Showing the geodesics on an ellipsoid

I have have code to the parametric plot of an ellipsoid: ...
54 views

### Shift+Enter key combination not working

Hitting the Shift + Enter combination is not working for me in Wolfram Mathematica. It just moves the cursor down, it doesn't produce any output: no computation or plot or anything visible. What ...
21 views

### How to find disjoint subsets such that union of the sets give the motherset or main set?

Let us define a set $\mathcal{S}=\{1,2, 3,\cdots,67\}$. I have a list of 132 subsets. I want to obtain 16(or 17) mutually exclusive subsets such that union of such 16(or 17) is equal to $\mathcal{S}$...
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### Changing the length of the edge of the Polyhedron

Hope you're having a great day! I made another post in regard of how to insert an image onto a face of a Polyhedron. I hope you could help me on this one too! I want to change the length of the ...
22 views

### How to find mutually exclusive subgraphs from a list a subgraphs to cover all nodes in a graph?

A list of 132 subgraphs (each with 4 nodes) is also available. A given node is available in multiple subgraphs. How can I find 17 subgraphs that are mutually exclusive (i.e., one node can be present ...
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### Problems with using the Ricci package

I think I have now managed to save the Ricci.m file, and also load the package on Mathematica. the instruction manual for the Ricci package is given here. When I enter Ricci.m, I get the following ...
38 views

### Modify each version of the Polyhedron with an Image

I'm new here, so I hope you're having a good day! I want to represent a Polyhedron with every face filled with my own Image of choice. Still, don't know how to do ...
32 views

### Neural network layer for vector normalization

We have a neural network that returns a vector $v$ with length $n$. However, these results $v_i$ must be normalized to unity so that their sum $\sum_{i=1} ^{n} v_i=1$. It must be done inside the ...
29 views

### Solve Set of Linear Equations (Analytic)

I have at a hand a set of linear equations of the form M*x=y (matrix form) M_ij * x_j = y_i where i = 1,...,N (in components) where M is symmetric, and all its elements are positive. Further, ...
57 views

### Inconsistent simple simulation outcomes?

Two simple kinds of simulating the one-sided exact Fisher-test of obtaining at least 86 successes in 129 draws in a population of size 299 containing 167 successes 1st Version is rather slow and ...
48 views

### New input cell style with a custom evaluator

I'm interested to implement a custom input style which would appear (mostly?) like a normal "Input" Cell, but which would ...
14 views

### Failed to use a R package via Rlink on Windows

I need to import .ibw (Igor files.) into Mathematica. For this I used 1) to go in R via Rlink (OS windows), 2) to load the package IgorR 3) to install it and then to use it. Here is a script which ...
23 views

### Possible to create an input cell containing Graphics/Graphics3D without Hold?

I am trying to implement a function that takes a Graphics instruction as its argument and then duplicated it in a new InputCell. ...
52 views

### Please help me find what is wrong with my code [on hold]

I am not getting a plot from the following code. Please tell me how to fix it. ...
32 views

### Discrepancy in the solution provided by NSolve

I have a code which goes like this: First one ...
52 views

### How to display the symbolic form of an equation?

I have this problem. I want to show the unassessed form of the equations that I enter in the graph, however, every equation that I introduce results in the substitution of the known values within the ...
71 views

### Automatically Trimming Noisy Experimental Data and Extrapolating It

I have experimental data which looks something like this I first want to remove the outlier points which are at quite high value such as around x= -10,000 etc, how to automatically trim these points....
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### How to use a given list of values for a parameter in FindInstance?

How should I specify a discrete range for a parameter as one of the conditions in FindInstance? MemberQ/Element functions don't seem to work. For example, ...
53 views

### Keeping specific terms in Mathematica output

After solving an equation I came up with a complicated expression, is it possible to only keep some specific terms of an expression ? As an example, if the expression is: How can I keep only those ...
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### DSolve Doesn't Return a Solution or Error

DSolve is not returning anything other than the original expression on ...
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### Formatting issues for importing into to Gephi from QGIS [on hold]

I want to use the network analysis software Gephi However I am having an issue with importing a CSV file from GQIS 3.6.2. It is saying that I am missing 'source' and 'target' and the node ids. I ...
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### How to solve integral equation involving Fourier Series

I have a set of equations involving two anti periodic functions $f(t+T)=-f(t)$ and $g(t+T)=-g(t)$ \begin{cases} f(t)&=J^2g(t)^3 \\ \mathcal{F}[g](\omega_n)&=\frac{1}{-i\omega_n-\mathcal{F}[...
28 views

### Typesetting environment for CloudDeploy

I am currently starting to develop a Web API for our schools mathematics placement examination for new students. We have the questions and we have what potential scores will mean for us. After ...
38 views

### How do I force a fractional coefficient to exclude non-numeric symbols?

Short version of question: Suppose I have an expression: expression = a+3b; When I divide by 2, I get: expression/2 It is ...
61 views

### Problem with FindRoot

I am very beginner to Mathematica and also a new user on Stack Exchange. I just need to find solution to the equations. I found an example similar to my problem on the internet. When I put following ...
24 views

### Expanding the complex conjugate of a Mathieu function as a series

In my calculations, I found this equation: ...
36 views

### Expand/collapse option for Toolbar

When creating a docked cell, the toolbar stays forever visible and somewhat "eats up" space. Since I do not use the different buttons all the time, is there a way to make the toolbar expand/collapse?
30 views

### Solving and plotting nonlinear system of differential equations [on hold]

I cannot get the graph of the system of differential equations below, can you help please?? ...
121 views

### Local variables in DynamicModule affected by outside evaluation

I was trying to use DynamicModule to create a Input cell that contains a variable assignment, where the variable name is given ...
16 views

### ForwardsBackwards running of a gif in Export

I'm trying to export a gif from a list of images The AnimationRepetitions command works, but the AnimationDirection does not. It just goes one way. Is there a way to loop back and forth? Here's some ...
19 views

### Improving NetChain for Physical data

I am trying to improve my NetChain to better predict physical data from the industrial standard for water/steam published by the IAPWS. Basically, this industrial ...