All Questions
92,185
questions
0
votes
0
answers
6
views
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
1
answer
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
0
votes
0
answers
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....
- 1
0
votes
0
answers
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 &...
- 183
0
votes
0
answers
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
2
votes
1
answer
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
-1
votes
0
answers
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), ...
0
votes
3
answers
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
1
answer
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 ...
- 11
1
vote
0
answers
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
4
votes
5
answers
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
0
votes
1
answer
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
2
votes
1
answer
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
0
votes
0
answers
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:
...
- 31
1
vote
0
answers
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 ...
- 103
1
vote
0
answers
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
8
votes
1
answer
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
0
votes
0
answers
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
...
0
votes
0
answers
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
0
votes
0
answers
47
views
Can Manipulate's execution result be represented by In&Out Cell?
I wrote the following code.
...
- 1,460
3
votes
2
answers
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
1
answer
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 ...
- 63
0
votes
2
answers
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:
...
- 491
1
vote
1
answer
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
2
answers
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
2
votes
3
answers
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
0
votes
1
answer
47
views
Sigma Delta Modulator in Mathematica
Below code is for 1st order sigma delta modulator used in ADC/DAC circuits.
...
- 41
3
votes
3
answers
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
1
answer
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
4
votes
3
answers
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 ...
7
votes
7
answers
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
0
votes
1
answer
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?
0
votes
1
answer
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
0
votes
0
answers
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:
...
2
votes
2
answers
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)...
- 31
0
votes
0
answers
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 ...
0
votes
0
answers
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
5
votes
2
answers
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
2
votes
1
answer
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 ...
- 583
1
vote
3
answers
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
1
answer
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 ...
0
votes
0
answers
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:
...
- 101
4
votes
2
answers
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
1
answer
65
views
1
vote
1
answer
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
3
votes
1
answer
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
-1
votes
0
answers
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
0
votes
1
answer
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
0
votes
0
answers
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
0
answers
30
views
functional derivative with respect to the partial derivative of the metric with xAct
I want to compute the functional derivative with respect to a partial derivative of the metric with the mathematica package xAct.
This is what I have tried so far:
...
