2
votes
0answers
238 views

How do I flip x and y value of a list in mathematica? [closed]

I am very new to mathematica. I have been trying to the following without any success. I have a list like this : data = {{1,2},{3,4},{5,6}}. I want a list ...
0
votes
0answers
89 views

How to use a While loop with NDSolve?

So basically I have this coupled ODE system I'm trying to solve numerically: ...
2
votes
1answer
115 views

Plot a function with a discrete part

I would like to plot a function like this one: ...
1
vote
0answers
39 views

NDSolve with external function [closed]

I have a complicated function g[a_,s_,t_] where s_and t_ are constants added by hand for ...
3
votes
1answer
241 views

Setting up parallel remote kernels

I'm having trouble setting-up a parallel remote kernel. I have correctly set-up remote kernels and can use them instead of the local kernels, by executing tunnel.sh ...
0
votes
0answers
120 views

RegionPlot3D of MeshRegion with VertexColor-like behavior

I regularly use the VertexColors option with GraphicsComplex[] to render images of objects with certain attributes at the ...
3
votes
0answers
183 views

Calling CUDA cuFFT

Following ybeltukov's excellent answers (see here and here) about how to access the CUDA library functions and interact with Mathematica through CUDAMemory, I tried to compile the code given in ...
3
votes
3answers
274 views

NIntegrate-ing a compiled function

I'm trying to integrate numerically in 6 dimensions a very long expression and I read about the option to NIntegrate a compiled function which should be faster. ...
2
votes
4answers
113 views

how to cancel arbitrary term in fractional formula

I often encounter this kind of problem that I want the fractional formula to be looked like the way I want it to be. For example, this one $$\frac{R^2 \left(g m_1-g m_2\right)}{J+m_1 R^2+m_2 R^2}$$ ...
3
votes
2answers
98 views

4D array not exporting to .mat file

I am using Mma 9.0 I am trying to export an array with Dimensions {5,100,160,160} to a .mat-file using the Export command, but ...
1
vote
1answer
180 views

Import csv file which contains columns of different lengths --> How can I delete empty fields?

I have the following problem: I want to import a csv file into Mathematica. I file as a lot of rows and columns, but the column lengths differ for certain rows. 2 columns always belong together, ...
0
votes
1answer
74 views

Unevaluated form of an expresion [duplicate]

I have two matrices - s1 and s2. I want their sum to remain unevaluated. For instance, the command ...
17
votes
1answer
583 views

Quit the Kernel and start new session automatically

The question is how to quit the kernel, start a new session automatically, and to be able to run such procedure from e.g. Button. This is especially useful when ...
1
vote
1answer
103 views

Traffic growth forecast: showing the change of linear regression

The following picture shows a changement in the trend of data. (The data used are available here). Is there any tool that can show this change of trend? Until now I managed to show even more ...
5
votes
2answers
156 views

Combinatorics: Placed errors

Consider a vector of length n where each element can take one of the values U, X, ...
2
votes
1answer
121 views

Dealing with functional equations

I have the specific function $G$ of $x$ satisfying the functional equation $G^3x=-1+G(1-x)+G^2x$. By using Mathematica, I would like to simplify the following polynomial of $G$ and $x$. $2 G^2 + 6 ...
4
votes
1answer
344 views

TimeSeriesModelFit incorrect?

I am trying to determine the optimal model for time series data (1592 observations). When I run TimeSeriesModelFit, Mathematica selects $AR(1)$ model, the estimated ...
24
votes
0answers
346 views

Documentation of the frequently-used functions in the context of Internal` and Compile` [duplicate]

In this site, I have gradually found out that there is a collection of functions in all kinds of answers. For instance, Compile`GetElement, ...
0
votes
1answer
95 views

Recursion depth and solving equations using Solve

I am trying to solve an equation: ...
0
votes
1answer
121 views

Trapezoid approximation to definite integral

this question is related to Basic question on defining more rectangles. I now was trying to adapt the code by MarcoB to get the approxiamtion of the integral by trapezoids, and I used the function ...
5
votes
1answer
233 views

Aligning transformed images to form a mosaic

I'm trying to align and stitch together these images to form a mosaic: It's a similar problem as this one: How to keep the non-overlapping parts when aligning images? However, (and I may not ...
0
votes
1answer
89 views

How to summarize the coefficient in Notation?

With the help from Stephen Luttrell in stackexchange, I can give an intuitive expression of quantum walk, as shown in the Mathematica codes below. ...
6
votes
1answer
102 views

Why are SetProperty and PropertyValue not working here?

I have a very simple graph, a loop: ...
1
vote
0answers
62 views

Clicking on a point on a plot [duplicate]

I want to click on a plot and have the pointer snap to the actual curve displayed. I found ways to click any random point on the plot but I want it to only click on actual points on the curve. I want ...
1
vote
2answers
337 views

How to Fit experimental data with 4D ParametricNDSolve?

Let me first explain the background problem. I'm trying to solve a problem with a projectile motion in 4D such that the position vector is: $\boldsymbol{r}(t)=\boldsymbol{r}[x(t),y(t),z(t)]$ I have ...
5
votes
2answers
145 views

How to manipulate graphs without losing properties like EdgeWeight?

Let's say I have a weighted graph, ...
1
vote
1answer
90 views

writing data in defined format into file

I have a code that writes datas into file using PutAppend[]. A simple form of the code is written below, ...
3
votes
0answers
77 views

How can I programmatically ungroup cells [closed]

I have a series of ~500 notebook files (created by a colleague), which somehow have had their cell groups modified from the default (perhaps accidentally by said colleague). In order to extract the ...
25
votes
4answers
410 views

FullSimplify wrongly reduces expression to zero

Bug introduced in 9.0 and persisting through 10.4 I get the following output with a fresh Mathematica (ver 10.0.2.0 on Mac) session ...
1
vote
1answer
211 views

Solution of a system of differential equations with a correction factor varying over time

Dear Mathematica users, I am trying to solve a system of equations of first order and time depedent. The system has 5 equations, one for every variable which varies over time. At the moment I am ...
8
votes
3answers
469 views

How to remove all dead ends from a undirected graph?

so what I want to do is take an undirected graph, and remove all the "dead ends" (that is, vertices that are attached to only one other vertex), but do it in such a way that it does it until reaches ...
2
votes
1answer
69 views

Import EPS and use as symbol

Is it possible to import a vector file & use as a symbol / plotmarker? I tried importing an EPS from Illustrator & assigning a name to it, but it failed. I would really like to be able to use ...
2
votes
2answers
87 views

Export Text with Colors

Is there a way of using Export[] method to take a text with colors (using Style) and then export to file, such that when I open ...
1
vote
1answer
175 views

Divide each element of a list of 500 matrices by another matrix

Lets say that I have a Table of dimension (3,3,500) and I'd like to perform element-wise division by a 3x3 matrix along the third dimension (of length 500 in this case). What is the most elegant way ...
1
vote
2answers
184 views

How can I import a table from a Wikipedia page?

I'm trying to import this table from a wikipedia page containing the list of lunar missions into a Mathematica as an Association. Here, I'm trying to use the new ...
1
vote
2answers
100 views

How to stop FullSimplify from returning Root objects

I have several expressions in a series, such as 1/4 (-(1/4) + Sqrt[5]/4 + I Sqrt[5/8 + Sqrt[5]/8]) (-1 - Sqrt[5] + 2 Sqrt[7/2 + (5 Sqrt[5])/2]) If I run ...
5
votes
0answers
160 views

Custom Methods for NMinimize/NonLinearModelFit

Is there a way to write custom methods for NonLinearModelFit or NMinimize? To give background, I currently have a batch of code ...
-3
votes
2answers
110 views

Random Polynom Plot [closed]

I should write a module "RandomPolyPlot[n, amin, amax]" which calculates all roots (nulls) of a n-th degree polynomial function. Then I should illustrate it on the complex plane. I also should ...
1
vote
2answers
173 views

Slicing multidimensional table

Say I have a multidimensional list created in the following way grid= Table[{i, j+1, k+2}, {i, 0, 1}, {j, 0, 1}, {k, 0, 1}] grid={{{{0, 1, 2}, {0, 1, 3}}, {{0, 2, 2}, {0, 2, 3}}}, {{{1, ...
3
votes
1answer
87 views

Why minimization does not work with symbolic array as arguments

If I try to minimize with constraints a function of several variables, with Gamma regularized function involved in the constraints it seems to works, as shown below (this is just a dummy example ...
1
vote
2answers
106 views

Get the sum with cases

I have the following list: list = {{1, 2}, {2}, {3, 4, 1}, {5, 4}, {3, 3}, {a, b, c}, {e, f}, {g}, {}, {Sin[a], Cos[b]}}; I should use ...
1
vote
2answers
263 views

NonlinearModelFit and plot with multiple parameters function

i ve got quite simple function: $f(t) = x1 * a(t) + x2 * b(t)$ and table of results like this one: t | f(t) | a(t) | b(t) ---------------------- 1 | 2 | 5 | 3 ---------------------- 2 | 4 ...
-3
votes
2answers
108 views

Write a function, write a pattern [closed]

I have the following list: list = {{1, 2, 4}, 6, 7, 8, {8, 2}, {3, 4}, {4, 5}, {1, 2, 3, 1}}; (a) I should write a predicate-function in combination with an ...
0
votes
1answer
51 views

Find/Write a pattern [closed]

I should find a pattern for the following expression: expr = {a^2, a^b, x^4, (x - 1)^2}; And that should be the result: ...
0
votes
1answer
172 views

Exporting multiple files [duplicate]

I used Mathematica to export plots of NM measurements with this code: Do[Export["Plot" <> ToString[i] <> ".pdf", Plottable[[i]], "PDF"], {i, NM}]; ...
0
votes
1answer
59 views

simple dynamical system with disturbance

I am new here and trying to simulate a very simple dynamical system with periodic force or Dirac function: $$mx'' + bx' + kx = u(t)$$ I want to draw the displacement(position) and velocity of the ...
1
vote
2answers
104 views

Why does InverseFourierTransform gives different result to doing it by hand?

When I can calculate an inverse fourier transform by the built-in function InverserFourierTransform, the result is different from what I calculate by definition ...
6
votes
1answer
100 views

Speed up the auxiliary function magicSquare when $n$ is doubly-even

Today, I saw a question about magic square (please see here). When $n$ is doubly-even, namely for Mod[n,4]==0 ...
3
votes
1answer
92 views

Want NIntegrate to catch error message

Really stuck with this. When I use NIntegrate, it sometimes prints a message like NIntegrate::ncvb: "NIntegrate failed to converge to prescribed accuracy ...
11
votes
5answers
584 views

Graphically approximating the area under a curve as a sum of rectangular regions

I am completely new to Mathematica. Basically I was trying to write a code to plot a function and draw the approximate area by rectangles. To be more precise, plot a function ...

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