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2
votes
0answers
69 views

Extract the dynamical map from the density matrix

I am working on open quantum systems and have been wondering whether there is a way to extract the dynamical map using mathematica. Say we have a density matrix $\rho(t) = \begin{bmatrix} p_{00} + (1 -...
3
votes
1answer
114 views

Difference in results between Integrate and NIntegrate

I was trying to ocmpute the line integral between the two zeroes of the function $f(x)=\sqrt{\frac{-x^2+x-1}{x^2(x-1)^2}}$. The zeroes are located at $(-1)^{1/3}$ and $(-1)^{2/3}$. I used the ...
3
votes
2answers
71 views

How do you make two interactive sliders dependent on eachother?

I have this code. Definition of q is: ...
0
votes
1answer
35 views

Modify evaluating process of selected functions globally [closed]

This is a little bold question and can look a little ridiculous. Q : Is it possible to modify evaluating process of selected function globally ? For example, ...
1
vote
2answers
64 views

Remembering function definitions across sessions to avoid recalculation [duplicate]

I'm working with some large expressions and fourier transforms, which usually take a long time to compute. When I save my notebook with outputs to all my inputs, I'd like it to remember those ...
2
votes
1answer
81 views

Why does Solve produce a result in terms of one variable, but not the other?

I have the following quartic equation:\begin{equation} x^4 + ax^3 + bx^2 + ax + 1 = 0 \end{equation} and I'm trying to find relations for $a$ and $b$ for which we have multiple roots. To this end, I ...
3
votes
1answer
70 views

How to verify series solution to an ode generated by AsymptoticDSolveValue?

To verify solution returned by DSolve, one can use the method shown in howto/CheckTheResultsOfDSolve.html and look for True (...
-6
votes
0answers
57 views

latex improvement [closed]

\begin{equation} \label{dia} IFR^{\nearrow ^{NBU}}_{\searrow _{IFRA}} \rightarrow NBUE \;\; \mbox{and} \;\; DFR^{\nearrow ^{NWU}}_{\searrow _{DFRA}} \rightarrow NWUE \end{equation}
1
vote
0answers
30 views

Why is PermutationProduct not yielding anything? [closed]

When I am trying to compute some products of permutations in S_48, it is somehow not working. Here is my code: ...
2
votes
1answer
53 views

Can one reposition the frame label in SciDraw?

I created this plot using SciDraw. I like everything about it EXCEPT the labels of the figure panels (a), (b), (c). They overlap with the frame. Can I move them a bit inward, just a smidge down in the ...
2
votes
0answers
78 views

Finding recurrence relation from an inexact numerical sequence

Consider the recurrence relationship d[0] = 0; d[i_] := (1 + Sqrt[1 + 4 d[i - 1]^2])/2 /; i >= 1 which generates the following sequence (generated by using <...
0
votes
0answers
43 views

Why is RMSE under the name “StandardDeviation” in NetMeasurements? [closed]

I wanted to calculate the RMSE of a neural network on the validation set to get an idea of its performance compared to other hyperparameters. It took a while for me to realise that RMSE is just under ...
0
votes
0answers
15 views

minimal subspaces in affine and linear spaces [migrated]

what is the minimum dimension of a linear space in seven-dimensional space, which contains one-dimensional and three-dimensional affine spaces? and what is the minimum dimension of an affine space in ...
12
votes
2answers
228 views

Library for FEAST method is missing

Mathematica (V 12.3.1, Native Mac M1 version) is not letting me use the FEAST method for solving eigenvalue problems. For example, ...
0
votes
1answer
54 views

How to get a single solution by simultaneously solving three equations with three variables? [closed]

I'm trying to solve the following three equations having three variables. ...
0
votes
0answers
35 views

Evaluating a function that is defined by Minimize

I want to find a global minimum of a function and plot the result for different parameters. ...
-3
votes
0answers
18 views

I need formula of function that decrease no linearly from x to y [migrated]

I need a formula of function that decreases no linearly from x to y over a set of iteration for example -1+t*((-1)/Max), this formula decreases linearly from 2 to 0 where t=0,1,2,..., Max. can I make ...
1
vote
2answers
84 views

Simplifying expressions with `Sign` functions to a single piecewise format

I have the following expression with many Sign functions: ...
2
votes
0answers
72 views

dot product of one thousand matrices [closed]

I have a time dependent matrix. In a thousand different times with the same time intervals I get the values of the matrices. Now, how can I DOT Product these thousand matrices in time order??
5
votes
3answers
402 views

`NIntegrate` with singularity does not work

Consider the following integral $$\int_{-\infty}^\infty \int_{-\infty}^\infty \frac{e^{-x^2-y^2}}{|x^2+y^2-1|^{0.6}} dxdy.$$ By changing to polar coordinate analytically and putting the result into ...
0
votes
0answers
35 views

Suggestions Bar doesn't always appear

Why does Mathematica sometimes show the suggestions bar like this: But in other cases it doesn't appear with any suggestions:
0
votes
2answers
63 views

Series solution to an ode does not satisfy initial conditions. Frobenius series. AsymptoticDSolveValue

I was trying to verify my solution to this ode using power series method. The expansion point is x=0. This ode has removable singularity, so Frobenius series and ...
2
votes
0answers
76 views

Use the mouse to pinch the plasticine

Very roughly speaking, a topological space is a geometric object, and the homeomorphism is a continuous stretching and bending of the object into a new shape. (https://en.wikipedia.org/wiki/...
3
votes
1answer
59 views

NDSolve unable to solve coupled ODE's after specific point

I am trying to solve a set of coupled differential equations that look like this ...
1
vote
1answer
69 views

How do I consider a list of items as a single atom when threading?

Suppose I have the following list of items: ...
0
votes
0answers
43 views

Mutiplying a list with a function [closed]

I am absolutely new to Mathematica and am trying to solve a very basic puzzle. I am trying to multiply a function (myStepFunc) to the column values of a 2D dataset and append two of these together ...
1
vote
1answer
83 views

Why InputForm of iconized output are hard to read in recent versions of Mathematica? How to correct it?

I never liked WRI tendency to now iconize some results from computation in the notebook. I do not know if this is the correct term for it. I like to see result always in plain normal code. Here is an ...
3
votes
2answers
58 views

Evaluation time for each evaluated cell (as a whole)

I have a Mathematica notebook that has a number of cells, and each cell has a number of code lines. Sometimes it takes long hours to finish evaluating each cell and I want to compare their evaluation ...
1
vote
1answer
77 views

Ordinary differential equation with variable (polynomial) coefficients -form of solution

If you have a differential equation with polynomial coefficients then quite remarkably Mathematica can find a solution. For example for the second order differential equation $ y''(t)+b y'(t)+\left(\...
5
votes
1answer
75 views

SetOptions not persistent between sessions

Let's say I decide I want all my axes to be colored red, so I do SetOptions[Plot,AxesStyle->Red] For the remainder of my session, I correctly get ...
0
votes
0answers
61 views

How to code Newton's method [closed]

I need some help with Newton's method in mathematica. Yes, I know that many questions have been asked about Newton's method, but I still don't understand I have to write a simple code for Newton's ...
6
votes
4answers
286 views

Generating large quantity of random numbers from an exponential distribution with fixed sum

I am trying to generate a large number (approx. 2 millions) of random numbers from an exponential distribution of the form: $$D(t)=\exp(-3000\, t)$$ The sum of the numbers must be 40. I use the method ...
-1
votes
1answer
63 views

how to plot multiple plots sharing a common X-axis and Y-axis

With the following Code, I generate various ListLinePlots but I like to create the example ...
0
votes
1answer
60 views

why this analytical formula can't yields the answer of numerical integration?

I have an initial function as follows ...
4
votes
2answers
75 views

Dataset division by dataset subtotals

I have the following dataset: ...
0
votes
1answer
54 views

Single computation is fast, but 6 computations are extremely slow

I have an expression that involves many Sign functions. I want to expand this in the piecewise format. My function is: ...
2
votes
0answers
48 views

ExampleData problem

When running : iris = ExampleData[{"MachineLearning", "FisherIris"}, "Data"]; I get the message : ...
1
vote
0answers
51 views

NDSolver cannot give precise result for extremely small values

I would like to solve an ODE with MMA. The equation is simply the Coulomb law. However, I cannot get a satisfying result: ...
2
votes
2answers
119 views

Is it possible to simplify this expression in Mathematica?

Let us consider an expression $$\frac{\sqrt[3]{\sqrt{2-x^2}+x} \sqrt[6]{1-x \sqrt{2-x^2}}}{\sqrt[3]{1-x^2}}.$$ Its plot ...
17
votes
1answer
837 views

Getting rid of the horrible Times x in Mathematica 12.3

Revised question to reflect new issues pertinent to Mma 12.3 and that are unresolved by the linked question - this is NOT a DUPLICATE and should not be reflected as such As of Mathematica 12.3, if I ...
0
votes
2answers
39 views

Can I set the limits of NIntegrate symbolic in a multidimensional integral?

I have written my integral as follows: NIntegrate[ f[re, rp, r], {re, 0, \[Infinity]}, {r, 0, \[Infinity]}, {rp, RealAbs[re - r], re + r}] but it returns ...
0
votes
2answers
61 views

How to show the excluded region in a scatter plot using margin or something else in mathamatica?

Here is my scatter plot I want show that the region lying in the range [Delta]=(0,40) and [Delta]=(140,190) is excluded. How do I show that? The code for my scatter plot is given below ...
5
votes
4answers
244 views

Any Mathematica techniques to calculate time takes to reach the equilibrium of a PDE solution

I am solving this PDE numerically (dimensions: spatial variable x and time t). I know how to solve my problem numerically (for a given range of time). The solution reaches its equilibrium after a ...
0
votes
2answers
184 views
0
votes
0answers
19 views

SetOptions error message upon launching Mathematica v.12

When launching Mathematica v.12, before opining any notebook, I get the following message: It does not afffect the execution of my notebooks, but it is annoying and I would like to understand how to ...
2
votes
1answer
51 views

Dealing with covariant derivatives (xCoba)

I do not understand why the output of the two commands: ...
0
votes
1answer
78 views

Stiff system problems with NDSolve

I'm trying to solve the two order differential equations using NDSolve. Here is the code: ...
-4
votes
1answer
79 views

How can transform the question into Wolfram language? [closed]

I've been sitting with this question: A graph has 7 corners. The degree of each corner of the graph is 3 or 4. How many edges does the graph contain if both degrees are represented? And this is the ...
1
vote
0answers
65 views

How does Mathematica numerically evaluate Gaussian Hypergeometric function $_2F_1(a,b,c,z)$ where $a,b,c \in \mathbb{C}$ [closed]

Gaussian hypergeometric function $_2F_1(a,b,c,z)$ usually takes $a,b,c \in \mathbb{R}$ and $z \in \mathbb{C}$. But using Barnes integral representation, one can analytically continue the $_2F_1(a,b,c,...
0
votes
0answers
47 views

Bayesian Linear regression (Ill-posed problem)

I want to use the ResourceFunction["BayesianLinearRegression"] from Wolfram function repository. With this function I want to solve the ill-posed problem $...

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