# All Questions

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### Listing most recently modified sections in Notebook?

I'd like to get a clickable list of all "Sections" that have been recently modified in my notebook, grouped by day of modification. "Modified" Section means, some cell under that ...
• 8,061
1 vote
17 views

### Absolute value of a complex number

I want to calculate |xx|^2. Why can't Mathematica just calculate it? What am I supposed to do here? I just want it to actually calculate it, so that there are no imaginary numbers left. Is that so ...
• 11
6 views

### Searching directory over a network

I have a network drive mapped on my Windows machine. I need to read data from the network that is nested in a few directories below the root. Example is "G:/Data/folder01/data/date_name/values....
9 views

### By what criteria does Mathematica generate the list of group elements in GroupElements[group]?

I ask because aside from always giving the identity element first, I have found a "pattern" associated with the list given by GroupElements[group]. This &...
28 views

### Solving the integral equation

Why does Wolfram Mathematica just rewrite my code instead of solving the integral equation? SigmaPhiBegin, SigmaPhiEnd are functions depending on Rho, Rho, bEnd, a, Kappa are constants. What needs to ...
• 1
27 views

### Export Notebook as Text (in 13.3 &14)

What is the best way to export a notebook as readable plaintext - while preserving as much structure as possible? The motivation here is the need to bulk-ingest notebooks and chunk them (for use in ...
• 3,601
20 views

### Specify a tensor or a function with a specific form in xCoba

Suppose, in the Schwarzschild geometry with the standard coordinates, I wanted to specify an electromagnetic tensor F with the (six) components all being functions of r: A(r), B(r), C(r), D(r), G(r), ...
81 views

### Plotting |z-2| < 1 under w = z/(z-1)

How can I plot the image of |z-2| < 1 under the transformation w = z/(z-1)? The expected result should look something like ...
• 495
1 vote
77 views

### Mathieu Floquet solution

Mathematica provides the MathieuC[a,q,z] and MathieuS[a,q,z] functions - as well as some other Mathieu-related functions. Maple ...
1 vote
58 views

### Can you explain this substitution rule?

This rule behaves as I expect: b . c + a . b . c /. (b . c) -> x (* x + a . x *) I would expect the same result with this: ...
• 16.1k
313 views

### Why does Mathematica not recognize a convergent series?

In one of my program run on Wolfram Cloud I run the command: Sum[(-1)^(Floor[k/2])/(k+1),{k,0,Infinity}] and got the response ...
• 649
28 views

### What is the fastest way to change Python environment?

We can see all registered Python environments through FindExternalEvaluators["Python"]. But the user interface will use the last registered one. How to ...
• 9,486
32 views

### Alternatives to Export to write long list as a table on a file

I have a large list (approx 50 millions elements). I could Export it as a table like this: ...
• 6,577
43 views

### Plot and mention extremum with corresponding points of extrema

Let sigma1(v), sigma2(v) and sigma3(v) with Im(sigmar)<0 (r=1,2,3) are the roots of the following cubic (in sigma^2) equation (1), say: ...
1 vote
34 views

### How to place Objects in Graphics in front or behind other objects using Inset[] in Mathematica13.3?

I made several 2DGraphics using Mathematica v12.0. To define if an object is placed in front of another or behind, I simply changed the order of the Inset. In this ...
1 vote
31 views

### How to assume a function is holomorphic?

For example, for a holomorphic function $f(z)=f(x,y)$, it's well know that $\ln |f|$ is harmonic. I want to check it with mathematica with the following code: ...
• 11
247 views

### How can we plot Man Ray's "Shakespearean Equation" w == e^(1/z)?

1. Man Ray Man Ray (1890 - 1976) was an American artist who spent most of his career in Paris. He was a significant contributor to the Dada and Surrealist movements. Man Ray produced major works in a ...
• 47.8k
28 views

### Create Constraints Iteratively for NMaximize [closed]

new to Mathematica so sorry for the silly question Trying to crete a list of constraints in Mathematica without typing manually as ...
34 views

### The Value is not Updated in the list/table [closed]

I have following data groupedTerms3rdcycle = GroupBy[term3rdcyclelist, Most -> Last]; where term3rdcyclelist is the list. I ...
• 123
47 views

### Can Manipulate's execution result be represented by In&Out Cell?

I wrote the following code. ...
• 1,460
197 views

### Contourplot with three variables

I have the following equation to generate a contour plot for it: ContourPlot[{(6 x^2 (-0.00001 + (z)^2))/(6 y^2) == 0.2}, {x, -1, 1}, {y, 0.1, 20}] It has three ...
• 361
1 vote
69 views

### Taylor approximation of integrals

I have BVP as in the picture and I want to solve it numerically by method given as follow. In the original paper, it is motioned that first iteration is computed and other are computed with Taylor ...
54 views

### Automatic FrameTicks with MaTeX style

I'm currently working on generating several function plots and have been using the following code as a template: ...
1 vote
93 views

### Using Reduce to simplify (not solve) system of equations

I'm dealing with a Mathematica program that generates a set of coupled non-linear equations involving an unknown function and its derivatives with respect to at least one independent variable. My goal ...
1 vote
97 views

### Normalized Coincident Detection Probability of Laguerre - Gaussian Modes

I am working on a paper in which a pump mode is passing through SPDC(Spontaneous Parametric Down conversion) is converted into two photons called as signal and idler. In which laguerre-Gaussian mode ...
• 23
163 views

### Manipulate list of equations

I have a list of equations: eqns={a/b==c,d/e==f,...,x/y==z} Now I want to muliply each of the equations with corresponding denominator, so that the result is: <...
• 39
47 views

### Sigma Delta Modulator in Mathematica

Below code is for 1st order sigma delta modulator used in ADC/DAC circuits. ...
136 views

### FunctionContinuous for a function defined with Which

The function: f[x_] := Which[0 <= x < 1/2, x^2, 1/2 <= x <= 1, x^2 + (x - 1/2)^3]; is continuous on the interval $0 \leq x \leq 1$, as a simple ...
• 39.9k
1 vote
51 views

### Selecting regions from the screen to capture dynamically

I know that by using CurrentScreenImage with some coordinates that I can capture regions of my screen. I would like to be able to capture a rectangular region of my ...
• 1,773
74 views

### How to add a column to a dataset made up of an association of associations?

A dataset can be created in at least two ways: first, from a list of associations, second, from an association of associations (I know that it is also possible to create it as a list of list and an ...
355 views

### Accumulated instance count of each list element

Given a list with repeated elements, for example: list = {m, i, s, s, i, s, s, i, p, p, i} I'd like to determine, for each position in the list, how many times the ...
• 1,325
50 views

### How can I add a point label to this plot? [closed]

I am using the listlineplot function. How do I label a specific point with text?
50 views

### Adding an empty circle to this plot, plus changing styles

I cannot find a god solution to highlight the intersection point between these two curves, in the plot I made: ...
• 779
63 views

### Help implementing Lagrange inversion

I'm attempting to find the coefficients of generating functions using Lagrange inversion. I am finding the series coefficients with: ...
207 views

### The center of mass of a semiellipsoid

I am trying to find the center of mass of a semiellipsoid using cylindrical coordinates. r^2/a^2+z^2/b^2 < 1, z < 0 the density = 1. I know that the center of mass is (1/M int,int,int rcos(theta)...
33 views

### Why do plots change in dependence on sample order?

I suggest two identical data set dat1 and dat2, save the order of samples is different. After selecting the first or the second data, the SCORE and LOADING plots are different. This seems to be in ...
58 views

### Determining special intersection points from 3D points defining a surface

I need to calculate a complicated integral. I asked a question: Method to compute this integral, but my question has been closed. First of all, I need to get the domain of integration. I have a ...
• 193
124 views

### Minimum/optimal number of tiles to cover all boxes

I have been struggling with the following problem. Given: the coordinates of a bunch of boxes/rectangles (in the form {xmin,ymin,xmax,ymax}) the overall image size ...
• 5,997
293 views

### How to make a polynomial so that f(i) = 1/(2^i)?

I know that, sequence has formula $f(n) = \dfrac{1}{2^n}$ satifying the conditions $f(1)=\dfrac{1}{2}$, $f(2)=\dfrac{1}{4}$, $f(3)=\dfrac{1}{8}$, $f(4)=\dfrac{1}{16}$. Now I am trying to find a ...
1 vote
92 views

### Why does assuming f[_] > 0 does not work while Element[f[_], Reals] does?

Refine works with symbols in either way: Refine[Sqrt[x^2], Element[x, Reals]] (* Abs[x] *) Refine[Sqrt[x^2], x > 0] (* x *) ...
• 11
1 vote
60 views

### Extract boundary points of an interpolating function obtained by NDSolve

Given a set of coupled nonlinear equations I want to extract the boundary points that appears in the interpolation function obtained as an output to NDSolve function and then to define them directly ...
41 views

### Issue with calculations involving sums [closed]

It is evident that the following holds: $$\dfrac{1}{a}\sum_{x=1}^{w}a^x=\sum_{x=1}^{w}a^{x-1}$$ This is demonstrated by Mathematica when writing: ...
380 views

### Largest integer between 1 and 1000 with no letter "n"

This problem is easy to solve logically - try it for fun if you want before you run the code and see the answer. ...
• 71.9k
1 vote
65 views

### Discrete number does not work well in DSolve

The code below works fine. ...
1 vote
39 views

### Delayed rule at StringReplace

In the StringReplace example(chaging two letter to uppercase) below, delayed rule is used. However, the result is the same even if rule is used. 1)The delayed rule must be uesd in this case? 2)In what ...
• 359
89 views

### Manipulate breaks when using the RegionFunction option?

For some reason, the code below breaks when using the regionfunction option with Manipulate. Am I missing something or is this a bug? ...
• 5,441
26 views

### Kloeden Platen Schurz Method [closed]

information about Kloeden Platen Schurz Method and general method, and how advantage of Kloeden Platen Schurz Method. we need all information about these method
63 views

### How do I copy what I enter into 'InputField' without any computational processing?

I made an InputField where I input the quoted sentences inside. And I set InputField to copy every time I run it. ...
• 1,460
83 views

### How to set the precision for the entire notebook

I want to do various computations conditional on a given precision for the entire notebook. I use the following code: ...
• 5,470
1 vote