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7 views

ParametricNDSolve and FindFit

I would like to fit a list of data: data={{x1,y1},...,{xn,yn}} My starting point is ParametricNDSolve with parameters a and b: ...
1
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1answer
14 views

How can I use a loop with an iterator in order to evalueate a function?

I'm trying to evaluate a function, that depends on two variables, in a specific set of values. I will write an example, but my system is more complicated. ...
2
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1answer
22 views

How do I order the solution of Solve?

How can I order the solutions of Solve from the one with the smallest real part to the one with the greatest real part?
2
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1answer
19 views

Why are those two mesh regions not the same?

In Mathematica, one can triangulate a mesh starting from a boundary mesh region. For example: ...
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0answers
14 views

Hot deck imputation for cleaning data

I am importing data for creating a machine learning classifier and at the moment i am cleaning the data. There are missing values within the data and are marked NA ...
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0answers
11 views

How to apply RecurrenceTable or Array in two dimensions

This question relates to 104959. How can I solve the following (akward) code by using RecurrenceTable or Array? ...
2
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1answer
24 views
1
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1answer
25 views
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0answers
12 views

GeoZoomLevel for GeoElevationData

I am trying to get a local contour map on an area of about 1.5x1.5 km^2. I am getting the following error: "GeoElevationData::chzoom: Unable to download data for zoom level 15. Using zoom 12 instead" ...
1
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1answer
43 views

How to Quiet[] only the first argument of Check[]?

I have a Check of the form Check[expr,failexpr, {NIntegrate::slwcon}] If expr throws slwcon, I would like to redo the calculation with higher precision by ...
1
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1answer
20 views

How to differentiate a composite function which includes unknown functions?

Let $f$ be a $C^2$ function from $\mathbb{R}^3$ to $\mathbb{R}$. Let $\Phi$ be the function from $(0, \infty) \times [0, \pi] \times [0, 2 \pi]$ to $\mathbb{R}^3$ such that $\Phi(r, \theta, \phi) = (r ...
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0answers
28 views

Why do I get different solutions if I use rational numbers?

Consider the case: L = 0.01; M = 10; Solve[2 L^2 M + r^3 - 2 M r^2 == 0, r] with solutions ...
2
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1answer
28 views

Is wolframcloud accessible from mobile devices?

I am having trouble accessing the free online platform for the most part of the last couple of weeks. I used to log on without any problem from my mobile device but for some reason I have not been ...
1
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0answers
37 views

DSolve unable to solve known second order differential equation

I am trying to solve a second order time dependent differential equation with a known solution. The equations I wish to solve are $x''[t]=\frac{-x[t]}{(x[t]^2+y[t]^2)^{1.5}}$ and $y''[t]=\frac{-y[...
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0answers
32 views

Plotting the surface spectral function

I'm not 100% sure if I should be posting this in the physics stack exchange but, I am pretty new to Mathematica, just installed it five weeks ago, and I am having a little trouble implementing the ...
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2answers
46 views

Importing multiple vector data file

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0answers
19 views

NIntegrate 3D Interpolation function in a region extracted from ListContourPlot3D

I have a list of 3D volumetric data points, e.g. for every position in 3D space there is a value. What I want to do is to firstly use "Interpolation" to get a function form of the data f[x,y,z] and do ...
0
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1answer
29 views

Relative error of a function

I need to make a program in which the function is given,the relative error of a function and the values of three variables,i need to find a relative errors of the three variables. This is given <...
4
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1answer
29 views

Prevent JLink from using a DisabledPreferencesFactory with Java on Linux

This is kind-of a strange question, so please bear with me. We have a Java application that has a utility for Mathematica 12 that lets you run our app from Mathematica using JLink. This works fine ...
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1answer
62 views

Manage to save large arrays

Some time ago I asked the following question: Merge list repeating elements I was easily answered and I was satisfied by the answer. However in computing such combinatorics, I saturated the RAM very ...
0
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0answers
16 views

Discrete plot horizontal axis start is incorrect?

In Mathematica 12.0.0.0 (Windows) the horizontal axis origin of DiscretePlot is 0, even when the index starts >0. For example, the DiscretePlot[i,{i,10,20}] begins at i=0 (with blank space), not i=10. ...
2
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1answer
43 views

Tick frequency (monthly to quarterly ) on DateListPlot

Probably a mundane question, but I am stuck. I have a time series of monthly observations, where the dates are specified as follows. ...
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0answers
10 views

Description of Menu Format -> style individual styles and their implications for the cell behaviour

Is there any documentation for the menu Format->Style? I wanted to include in the notebook examples of the code and I used for those cells the style called ...
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0answers
19 views

Problems with fonts when printing or saving as PDF on Fedora 31

I've run into a really frustrating problem with Mathematica 12 on Fedora 31. When I print to a PDF file or save a notebook as PDF, all text comes out garbled. Here's a small example: It also shows ...
2
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1answer
52 views

NIntegral and Integral compare: which one is more accurate when integrand is not integrable?

I am calculating the following integral $$I=\int_0^1 e^{-c_1x^2+c_2x}\mathrm{erf}(c_3x+c_4)dx,$$ with Integrate and NIntegrate ...
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0answers
25 views

Difficulty for using ArrayPad with Matrix

I have a matrix M which is 4x4. How can i create a 7x7 matrix with : the 2 first lines are 0 the 2 first columns are 0 the last lines is 0 the last column is 0. For the moment, I can do it like ...
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0answers
33 views

Abort evaluation in only one window?

Is there any way to abort evaluation only in one window? I tried both alt . and quitting the kernel, this stopped evaluation in all windows and actually lost me some time because I only meant to ...
6
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1answer
126 views

Drawing the basin boundaries

In my case, I need to use the following data file Let's plot the basins ...
2
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0answers
109 views

Making cool animations of an accretion disk/planetary disk

I am trying to make an animation of an accretion disk or a planetary disk. For example, a cool disk showing below (created by NAHKS TR'EHNL): or in this link Here is what I have tried so far: step1:...
1
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1answer
36 views

DSolve with multiple equations

I'm trying to solve the following system of differential equations: ...
0
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1answer
41 views

Combining two plots with different x-axes and not labeling the x-axis

Below two figures are just for example. What should I do if I want to plot the two figures below on the same plot with the same y-axis only that the x-axis is also same but not labeled such that. As ...
2
votes
1answer
33 views

How do I make some edges in a graph invisible?

I have a number of nodes, each with a numeric label and arbitrary connections between these nodes. When I plot the graph I would like nodes similar in value to be colocated as far as possible within ...
1
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1answer
18 views
0
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0answers
21 views

How to find the primitive Heron triangles with three rational angle-bisectors by MMA?

I'd like to find the primitive Heron triangles with three rational angle-bisectors. In a Chinese book, I saw these primitive Heron triangles with three sides no longer than 1000, but I'm not sure if ...
2
votes
0answers
23 views

An efficient way to extract Dependency Strings from a sentence

Mathematica has the built-in function TextStructure, with the option "DependencyStrings" that provides the dependency strings of a sentence. Unfortunately, this function is incredibly slow. ...
0
votes
1answer
38 views

NDSolve third order PDE with boundary conditions

I am trying to solve following PDE involving a third derivative with respect to p: ...
1
vote
1answer
45 views

How to get the value of each item in the list and keep the structure of the list

I want to get the value of each item in the following list and keep the structure of the list, get the result ...
1
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1answer
100 views

How to calculate a hard definite integral?

I have the following function of $4$ - variables ...
0
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1answer
38 views

Double Sum Computation Issue

I'm trying to compute a double sum... For scalars, it seems to be working fine. Here is an example: ...
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0answers
23 views

How to implement a function within a function for Newton's method?

I have to evaluate different versions of Newton's method and the article where those equations come from have function defined within the method. For eg. ...
2
votes
1answer
82 views

insufficient boundary condition error

I wish to solve the initial value kdv equation with a boundary condition that particles are fixed at the end points. Below is my code. ...
1
vote
1answer
32 views

Increasing point size in 3D + color plot

I have a "4D" plot (3D + color) that I want to increase the point size of the points. Seems easy enough right? Just use the following is what I thought: ...
-1
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0answers
28 views

Shifting Scheduling [closed]

i have 4 staff in my office work in shift, the shift devided in three part s3 (morning 5AM to 13PM) s2 (afternoon 13PM to 09.00PM) s1 (night 09.00PM to 05.00AM) in one month let say 30 days, i have ...
1
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1answer
26 views
1
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0answers
30 views

Plot is passing a bizarrely shifted x_min value to the user-specified Ticks function

The documentation for Mathematica's Ticks option says that you can specify the ticks for an axis by passing a function rather than a plain list description. The ...
0
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0answers
41 views

Virasoro algebra [migrated]

My question here is very computational. My problem is in mathematical physics, so I want to ask the community what kind of software they use to do the following computation if there is any? Let $$L_{...
2
votes
0answers
36 views

Why the built-in function `LegendreP` is slower than the custom function

In my test, I found that the built-in function LegendreP of MMA is not as fast as the user-defined function. MMA should have already compiled and optimized the ...
2
votes
0answers
40 views

How to show Mathematica full output of a big Graph

I developed a Graph with 100,000 nodes and 402,000 edges. However, I can't see it because the output is truncated: Also, when I try FullForm I get memory error, even with a 32 CPUs, 120GB RAM + 8 ...
0
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0answers
23 views
0
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0answers
31 views

Manipulate a parametric curve [closed]

I wish to manipulate a parametric curve with a parameter being the end-point like the following: ...

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