# All Questions

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38 views

### What font is used for the TraditionalForm? [closed]

What font is used for the TraditionalForm?
345 views

Writing: ...
56 views

### Find FT and r.m.s noise of a signal

I have a signal : ...
148 views

### Incomplete path when using NotebookDirectory[] in ver 12.1.0 and Dropbox

I just upgraded from version 11.3.0 to version 12.1.0 and I am struggling with the directory of my .nb file. Usually I start all my .nb with ...
200 views

### How to solve these algebraic identities?

I need help in finding/solving these types of algebraic equations using Mathematica. here is the problem/code. I tried using 'With' command but no use. Thanks in advance. ...
45 views

### Output is derivative of state variable

Given simple system of ODE. \begin{cases} \dot{x_1}=-x_1+u \\ \dot{x_2}=-x_2-x_1 \end{cases} As an output, I want to use $y=\dot{x_1}$. But when I use the ...
50 views

### Solving Complicated Systems of Equation

If I have three equations as below: $a_j = -(k+\sum_{i\neq j}^n\alpha_iba_i)^{-1}$, say $i,j=1,\cdots,n$. I want to use Mathematica to solve this system of equations but I do not want to solve it ...
153 views

### Bug in Series[Pochhammer[1+n, n], {n,Infinity,1}]?

Bug introduced after 5.2, fixed between 12.0.0 and 12.1.1. The function Pochhammer[1 + n, n] tends to infinity. We have ...
81 views

### Polar axes on a RegionPlot do not appear in correct location

I'm trying to plot the region where some complicated function $f$ is positive, within the circular region 0<R<π/2. I based my code off this answer, however the resulting polar axes do not appear ...
76 views

### Plot with lines highlighting different regions

I want to plot Plot[{Sin[x], 0.3}, {x, 0, 2 \[Pi]}] with the portion below 0.3 highlighted as by lines as shown
100 views

### How to plot a portion of a curve and the area under it [duplicate]

I want to display the portion of the curve Plot[Exp[-x^2], {x, 0, 1}, PlotStyle -> {Blue}, Filling -> Bottom, GridLines -> {{0.6}, {0.7}}] (and the area ...
41 views

### Return is not returning a value in a recursive module [closed]

I have a recursive function executing a search in a family tree to find lines of descent. I have a line If[curnode == pers2, Return[curpath]]; This functions as expected in cases 1,2,or 3 ancestors ...
38 views

### Plotting a function with restrictions

I am trying to plot the following $U_a=\frac{wXn_l}{n_a}+H$ as a function of $s$ which is given by the expressions below, where I assign values to the constants ...
40 views

### Is it possible to trigger some Mathematica code when an error of the type StringTake::take happens?

I process data from various sources (databases) that are formatted very inconsistently. I would like to be able to process them finally summarized in one piece. My code consists of many cases of ...
91 views

### HatchFilling in Mathemathica fills the entire are under curve

The Hatchfilling command is failing for me, i want to fill the area under the curve with vertical lines. If any suggestions plz do share. Thankyou.
52 views

### Draw first few sides of a polygon thicker than the remaining sides

I use the following code to draw an n-polygon where the first t sides are meant to be thicker than the remaining sides: ...
57 views

### Simplify a heavy calculation

I'm aware that this may be regarded as too non-specific and with too little information, but I hope that someone will be able to help me nonetheless or to request information which would be imperative ...
85 views

### NDSolve not working : Step size zero, singularity/stiff system suspected

I am trying to solve a set of four coupled equations through NDSolve. However, I am getting the error "NDSolve::ndsz: step size is effectively zero; singularity or stiff system suspected.." ...
389 views

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31 views

### Unable to find the plots of NDSolve [closed]

My code is given below ...
67 views

### Poor label and legend resolution using MaTeX

I am using Mathematica 12.3 and the MaTeX package in order to typeset my labels and legends correctly. I get quite blurry text and I don't know if there is a way to improve the resolution of the ...
55 views

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### Plotting a function with a variable distributed uniformly

I am trying to plot the following as a function of $s$: $$u_f= \frac{P(S-s)\sigma_i}{n_f(s)}+H(s)$$ where $\sigma_i$ is distributed uniform on the interval $[\sigma_l,\sigma_h]$, and $s \in [0,S]$. ...
41 views

### How to compare and subtract elements in nested list to generate a new list [closed]

I have list of lists like this one: list={{1, 9, 4, 7, 2}, {1, 4, 7, 1, 8}, {0, 5, 7, 2, 9}} where every nested list have 5 elements. I want to compare the third, ...
64 views

### Can't find parameter with findFit NMinimize

I have a data list and a function being to be fitted to the data to get parameters of the function as below. I can't find the parameters a, b, c, d with different below methods. Can you help me to ...
143 views

### How would you set up the folllowing differential equation in Mathematica?

I have 20 coupled differential equations and would like to solve them numerically in Mathematica. How would I set this up in some vectorised way?
70 views

### ColorReplace with thresholds and connected components

I would like to replace the colors in this drawing (called img) with colors of my choice. (For simplicity, we can assume my desired colors are ...
21 views

### PredictionLimits not working for time series

I'm doing an ARIMA forecast with daily data (but that is formatted as year-month-day-hour-minute-second, although hour, minute, and second are always zero) and I'm trying to get the prediction ...
43 views

### Improving label collisions for Tree/Graph?

Historically, MMA has never handled label collisions well, but recently they added some improvements here via things like Callout. I want to fix ImageSize but still ...
32 views

### Plot a function: inputs needed [closed]

I'm trying to graph the function ua using the following code: P=1;[IndentingNewLine]w=1;[IndentingNewLine]x=2;[IndentingNewLine]nl=3; n = 5;[IndentingNewLine]S=1;[IndentingNewLine]sigmaL=1;[...
39 views

### How to intelligently use FullSimplify and FunctionExpand to simplify complex sums

I am trying to find a compact form of some sums which is related with some Bayesian probability factor (not so relevant, if required further explanation please ask). The point is that I know that the ...
46 views

### A function that maps Held symbol to string

Rougly my question is about constructing a function that maps Hold[var] to "var" even when var has an assigned value. In details : ...
42 views

### Problems with NSolve[] finding zeros of a 32-degree polynomial

I have the following calculation in Mathematica: ...
99 views

### Making an expression to Iceberg-like object?

Can we construct a function Iceberg, which maps a given expression X to Iceberg[X] satisfying 1. and 2. and 3. ? 1. From Iceberg[X], it is not possible to inspect/extract a part of X with usual ...
83 views

### Convergence and efficiency of 5-dimensional numerical integral using “GlobalAdaptive”

We have a 5-dimensional integral arising as a solution to a physics problem, where two dimensions of the integration space cover the spherical and azimuthal angle, and three dimensions are needed to ...
381 views

### Creating a variable from Reduce[] output in Mathematica

Say I have the following input: Reduce[{t*c==50, t==5}] the output: t == 5. && c == 10. Is there a way to create a ...
75 views

### Get the trajectory of an object in a gravitational field

Given the initial position and velocity, I want get the trajectory of an object in a gravitational field. Instead of using Kepler's Laws, I want to solve the following differential equations: ...
125 views

### _?NumericQ inside NDSolve to speed up code

I've seen some people using _?NumericQ to prevent symbolic calculation and speed up NDSolve. Why in this simple code is not ...
464 views

### How to construct a tree from a preorder traversal

The list t1 = {1, 2, 3, 3, 4, 4, 3, 3, 4, 3, 3, 2, 3, 4, 2, 3, 2}; might be derived from a pre-order traversal of ...
216 views

### What is the relationship between the Wolfram executables? Where is this documented?

The relatively new wolframscript now accompanies the traditional math and wolfram binaries. ...
117 views

### How to speed up the calculation process of a symbolic matrix?

There are a symbolic matrix and a real number list. I'm going to replace the symbols of the matrix with all the elements of the list, and then to get the Eigenvalues...
122 views

### FindGeometricTransform not working properly for a simple problem

I am surprised why FindGeometricTransform is failing to automatically register or align two sets of points that are drawn from a ...
161 views

### Bilinearization with Mathematica - where to start?

I tried to bilinearize the two equations: ...
29 views

### Automatically export .nb to a package upon saving while preserving section headings

Is it possible to automatically export a .m package when I save my .nb as can be done using the option ...
54 views

### How can I store vectors in a matrix

I am triying to generate realizations of a Gaussian random process using the KL expansion. For that, I need to multiply an eigenvector for an eigenvalue and a random variable. I have tried ...
55 views

### Find all substrings from a string by deleting characters from it

Problem Description : I need to create all substrings from a string by deleting letters from it without re-arranging the rest of the letters. For example, "us" is a substring of "...
155 views

### Using DataStructures in FunctionCompile

This is a follow up to this StackExchange question I am trying to do the equivalent of Select on a "FixedArray" data structure. Here is what I have tried so far: ...
39 views

### ListLinePlot outputs a blank graph [closed]

My program contains a variable like this ...