# All Questions

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38 views

### help with plotting functions in Block and ContourPlot3D

I have a question regarding Block. In Doc, Block[{x=x0,…},expr] suppose we have two functions in ...
545 views

### Merging 4 matrices to one matrix

I am struggling with the task to merge four matrices as presented below. Since the matrices A-D contain more than just four entries it would be too complex to do it by hand. Is there a simple or ...
32 views

### How to make Button print the last updated point?

I am trying to create a graphics that outputs the population of a city on the graphics that is clicked. The problem is that it is not updating the last point that is clicked. Please help. ...
30 views

### Using Show to combine two plots made with DiscretePlot3D [closed]

I used DiscretePlot3D to plot my equation, but when I tried to combine two different plots into one, Show did not work. Do you ...
107 views

### Destructuring a list containing two items to use it as arguments to a binary function

I'm experimenting with the Through function. I suspect there is a way to use that function to obtain both the mean and difference of two values. But this doesn't ...
72 views

### Replace elements of a list if the conditional is false

There is a list: {1, {a, b, c}, 1, {1, 2, 3, 4, 5, 6, 7, 8}, {A, B, D, Z}} It contains sublists of different elements and several $1$s. The goal is to replace ...
205 views

### Making one list from two lists by grouping them in a special way

I have two lists: list1 = {{{x1,x2},{x3,x4}}, {{x5,x6},{x7,x8}}}; list2 = {{{x9,x10},{x11,x12}}, {{x13,x14},{x15,x16}}} I need to join them to get one list: <...
58 views

### Why is Log[8 E^(3 Log[0.5]) != 0 [closed]

My wife and I have tried to calculate Log[8 E^(3 Log[0.5]) on a TI-Nspire and we got the result -8E-14. We have changed th settings of calculation to Exact and the result was 0 (correct) If I use ...
29 views

### Converting String in “Data” Format within Mathematica [closed]

Hi I have a simple question. Given a random string in the format accepted by the Import[fileWithString, "Data"] i.e the file contents being ...
25 views

### Lightweight Grid: transfer a file to the master kernel?

I am trying to run code on a Lightweight Grid using ParallelDo. I have ~300 jobs that each take ~20 minutes to run and produce ~8 MB of data, and I am using a ...
49 views

### Having trouble understanding code to do formatting with MakeBoxes

Can anybody explaining this code? ...
44 views

### How can one combine multiple DensityPlot3D plots so they are all equally visible in the final plot?

How can one combine multiple DensityPlot3D plots so they are all equally visible in the final plot? Here is an example: ...
57 views

### Finding frequency of oscillation of an particle by Fourier analysis of the trajectory

I am trying to find the resonant frequency of a particle by Fourier analysis of the trajectory. Here is the data file. ...
88 views

### Plotting eigenvalues

I am trying to reproduce figure 10 in the linked paper. The authors have used Matlab bvp4c function to find multiple solutions for the system of ODE and then carried out the stability. Here is my ...
42 views

### How to find the derivatives from Solve after obtaining 6 complex solutions?

I have a 3x3 matrix. By setting the determinant to 0, I find the values of w in terms of ka and graphed the complex solutions. m, M, k, l are constants: ...
22 views

### Standard Error not right with Linear Model Fit [closed]

I tried using linear model fit according to the example found here https://reference.wolfram.com/language/ref/ConfidenceLevel.html I noticed that ...
36 views

### Force UnitConvert to display the proper unit prefix and return inexact quantities?

I'm experimenting with units: UnitConvert[1/Quantity[2.0, "GHz"]] 5.*10^-10s ...
48 views

### Obtaining the results of tagged cells in a notebook from another notebook

My objective is to read the results of several tagged cells in a notebook NB1 from another notebook NB2. Following the ...
257 views

### Integrate over a region

I am trying to calculate a integral over a region defined by But I dont really know how to do it, I dont know if I have to work in cartesian coordinates or polar coordinates. The function that I ...
80 views

### Code doesn't run on my system but runs in another system

I have an issue with Mathematica. I have some code and its answer. When I run the code on my system, it doesn't work. The person who wrote the code believes that is correct, and I agree. I tried to ...
45 views

### Converting an image of a plot to a plot?

Does Wolfram have the ability to (attempt to) convert an image of a arbitrary plot on the web, say: to its corresponding Wolfram representation (in this case:...
150 views

### Build a matrix from the coordinates of its elements and complete it with zeros

Suppose that I have a data set data (input): ...
44 views

### Comparing two methods of integration [closed]

Given two tolerances (like 10^-3 and 10^8), how can I compare accuracy of the two methods (explict Runge-Kutta and Adams) for the following system  ...
56 views
+50

I'm using Manipulate together with CreateDialog to run a ListPlot whenever I click on a ...
117 views

39 views

### StreamPlot hangs if streamPoints are outside the range specified

Is this a know issue? The following MWE works and gives plot immediately ...
19 views

### How to estimate parameters of TransformedProcess?

Let's say we have the following time-series. ...
48 views

### Retrieving the evaluation result of an Initialization Cell in a notebook nb1 from another notebook nb2`

I have a very long code in a notebook nb1 in which all the initialization cells are tagged. I have another notebook nb2 where I ...
54 views

### A single expression that performs substitution and simplifies a trigonometric form

I'm very new to Mathematica. I searched through the online documentation, but I don't understand why it realizes that $\sin(n\pi)$ for $n\in \mathbb{Z}$ is $0$: ...
31 views

### Extra white line in densityplot's output

How can I remove the white line in $y=0$? This is my code: ...
33 views

### How to solve an under determined system for a ratio of variables?

I have two equations in 3 variables a2, b1, b2: ...
61 views

### Track the location of of dot from noisy image

https://imgur.com/a/SnTYESG (subtraction between the image) https://imgur.com/a/ZdOS5wf (orignal image) From the original image, since my CCD camera is bad, I cannot really see anything. However, ...
41 views

### Writing code to produce continued fractions

I have been trying to create a continuing fraction to help prove the theory about any rational number: a/b being able to be written as a continued fraction where the remainders found in the Euclidean ...
33 views

### How to use FirstPosition in compiled function

I am trying to compile something similar to the following: test = Compile[{{data, _Real, 1}}, First@FirstPosition[data, _?(# > 0 &)]] However I get the ...
69 views

### Mathematica derivative not matching when I take derivative by hand

I want to take the derivative of this with respect to eta: fabc = 1/2 (-3 + 27/(2 + x)^2 + (1 - 1/(1 + (-1 + x) c[eta/cc])^2)/ c[eta/cc] + 2 Log[x]) Here I ...
43 views

### Plotting solution of an integral

I have used below code to plot the solution of an integral, but the code doesn't return anything. Could somebody please help me in this regard? ...