All Questions

1
vote
0answers
8 views

How to find the cells of a region that intersect a line?

I'm looking for the fastest way to access the mesh cell (i.e. polygon) in a Region that intersects a Line in 3D. For example, <...
0
votes
0answers
12 views

how to implement the following correctly and estimate paramters?

I want to implement something like the following and estimate its parameters. this has state variable being subject to DiscreteMarkovProcess. For estimating,this process requires estimating of Matrix, ...
1
vote
0answers
45 views

Find the nearest balanced integer

OEIS A036301 is a sequence of numbers $ n $ such that the sum of the even digits of $ n $ equals the sum of the odd digits of $ n $. Let's call these numbers "balanced". Given an input positive ...
0
votes
0answers
27 views

Removing zero dot after solving

I've a question regarding "zero dots". Im using a lot of calculation in an application which i am building within mathematica. However when i use the output of solve for instant i will not have the ...
0
votes
0answers
22 views

How i can calculate the frequency of 2D data?

Hello, i have one .txt file of many data in two column: x(i) y(i) . . . . . . for example -.05
0
votes
0answers
32 views

Find the maximum of Floor[(1/2)(Floor[H/p]+3-Sqrt[(Floor[H/p]+1)^2 - 4H])]

The constraints are H >= p(4p-1), p is prime although not necessary for this problem. From numerical tests I see the maximum to be 2p at H = 4p^2. I need to prove this. The derivative of the Floor ...
1
vote
1answer
28 views

Peculiar result of InverseHankelTransform

In using the HankelTransform and its inverse I find that the inverse does not lead to the initial input. I begin with r (the independent variable) in the denominator but end up with r0 (a constant) in ...
0
votes
1answer
41 views

Find permutation index

Firstly I wanted to find all the non-negative integer solutions for the following equation given the value of $k_{max}$ $$ k_1 +k_2 +k_3+k_4 = k_{max} $$ For this I use the following code:- ...
0
votes
0answers
48 views

Plot `k/2Pi` instead `k`

I have a function ω[k]: ...
1
vote
0answers
14 views

“LinkConnect::linkc: — Message text not found” on startup, removing ~/.Mathematica helps

We have a university license of Mathematica. In /usr/remote/Wolfram/Mathematica/10.3/Configuration/Licensing/mathpass on all the Debian 9 systems we have the ...
0
votes
1answer
48 views

fast sum computation

I would like to compute sum. How is it possible to compute the sum fast? May be with the help of replacing Sum with NSum or <...
1
vote
0answers
18 views

use of PopupMenu

I have the following code: PopupMenu[Dynamic[choose], {al, bl, cl}] and vin1 = Dynamic[choose] then, I would like to use ...
1
vote
0answers
23 views

Normal form for Hopf bifurcation

I'm trying to obtain the normal form for the Hopf bifurcation using mathematica. I was looking at the following article: downloads.hindawi.com/journals/sv/1995/581272.pdf and I´ve tried to solve (25)...
1
vote
0answers
52 views

Wolfram Engine on new ARM-based AWS-EC2 instances

Is it possible to install the RPI version of the Wolfram Engine on the ARM instances of AWS? Otherwise WR could distribute a version of CDFPlayer for ARM, do you think they are willing to do it? That ...
0
votes
0answers
28 views

Why does noting show up in Plot? [on hold]

I am trying to plot the following code in Mathematica, but nothing shows up. Any tips as to how I can resolve this issue? ...
1
vote
1answer
52 views

Why can't I plot two graphs on the same plane in WolframAlpha?

When I plot these graphs separately everything is OK, but when I try to plot them simultaneously I get error. Why?
0
votes
0answers
35 views

Using List to create lists of strings: difference(s) between two one-line codes?

In the Virtual Book of Mathematica, there is a simple example to show how to create lists of strings by List: ...
2
votes
1answer
39 views

How to build a TemplateBox with dynamic length GridBox

I have created the following TemplateBox Rule. ...
0
votes
1answer
71 views

How to define a function only for integers

I want to create a function which only accepts integers. if a value other than integers are given it should output zero. This is what I've tried so far. I'm trying to do some discrete time signal ...
0
votes
0answers
31 views

NIntegrate weird behaviour inside a function

I wrote this little function ...
1
vote
1answer
56 views

Difficulty in finding the peak in the data

I have a set of $ x $ and $ y $ data. The $ y $ data is represented in a logarithm scale and the $ x $ data is in linear scale. I have used FindPeaks function to ...
0
votes
0answers
67 views

DSolve for ODEs with terms like $ y^2(t) $

Mathematica does not give me any solution for the ODEs as follows: ...
0
votes
0answers
52 views

Output Changing when calling Block twice

I'm trying to optimize my code a bit, and I'm having some issues with block. Here's the block ...
1
vote
1answer
66 views

speedup of DimensionReduce

I am interested in accelerating DimensionReduce using the "TSNE" method. I have a matrix with a size of 30000 * 10, and I want to reduce to 30000 * 8. But the calculation is very slow, any suggestions ...
2
votes
2answers
53 views

Regarding SwatchLegend and ColorFunction

Can I use ColorFunction in place of color in SwatchLegend or is there any way to include ...
1
vote
2answers
34 views

Define x as a multiple of a number as a constraint in the Maximize function

I am trying to optimize a linearly constrained Production Function. I have three inputs and want them all to be multiples of 150. I can make all the inputs to belong to the Integer Domain but is there ...
1
vote
0answers
56 views

Finding root of symbolic function

I'm trying to find a root of the following equation $$\theta^\frac{t}{s}-\theta-\sqrt{1-p},$$ where $0<t\leq1\leq s$ and $0<p<1$. I've tried FindRoot and Reduce, but somehow they don't ...
1
vote
3answers
58 views

Most efficient way to replace/ update the values multiple rows and columns of a Dataset

Suppose we wish to replace the cols "b" and "c" of rows 3 to 5 in the following dataset to b and c respectively: ...
2
votes
0answers
26 views

Speed up Mathematica's Simplify and ComplexExpand functions

I am trying to simplify an expression and taking the real part only. However Mathematica use ages to run the command (if it is able to do so in the end). The problem is that the expression I am ...
2
votes
1answer
33 views

How to remove InputAlias created using notations package

If i create a custom input alias using Notation package's AddInputAlias. Now it appears in the list generated by ...
2
votes
1answer
60 views

Fullsimplify with two Diracdelta functions

I am having a problem with the FullSimplify and DiracDelta functions. When I run the following line in mathmatica: ...
0
votes
1answer
18 views

NIntegrate: The integrand has evaluated to non-numerical values for all sampling points in the region with boundaries {}{}

I encountered a problem with the NIntegrate function while simulating a physical situation. The expression is quite messy, but it is just an integration over a polynomial so it should be possible. I ...
1
vote
0answers
28 views

Issues with smooth histogram [on hold]

I have a list of data, regarding particle size and I want to get a plot of the particle size distribution. For some reasons I can plot my data into an histogram using Histogram [data, Automatic, "CDF"]...
9
votes
3answers
1k views

Can this be solved even faster?

So I would like to solve the following set of equation for $m_i$ given a set of ${M_m,N_m}$. $$ m_1 +m_2 +m_3 +m_4 =M_m \\ |m_1| +|m_2| +|m_3| +|m_4| =N_m $$ All variables are integers. Also $N_m \...
2
votes
1answer
87 views

Finding all roots to equation [duplicate]

I'm currently doing some Mathematica exercises, and I'm stuck on this one task where you're supposed to plot the functions h(t)= |3-t^2|+|t-1|-t^2 , g(t)=3sin(t) in the same grap, and then find all ...
2
votes
0answers
44 views

How can I perform the modified Cholesky factorization/Decomposition in Mathematica?

How to "Modified" Cholesky Decomposition in Mathematica? what I mean: V = L . D . Transpose[L] V is p*p(row is p,columns is p) non-negative definite matrix, D is diag[$d\small1$,$d\small2$,$d\...
0
votes
1answer
79 views

Why can't I iterate?

I encounter a problem when computing the following equations: ...
4
votes
2answers
76 views

Why Can't Mathematica Resolve this Simple Quantified Expression?

I've been using Mathematica as a hobbyist, off and on, for some time. So while I'm by no means an expert I've used it long enough to know that what might seem obvious to me is not necessarily obvious ...
2
votes
1answer
33 views

Plot and Legend color mismatch due to opacity

I have the following code: ListContourPlot[data,Mesh->None,ContourStyle->None, PlotLegends->Automatic, BaseStyle->Directive[Opacity[0.3]]] Due to ...
0
votes
0answers
44 views

Nominal problem with Solve, Reduce, FindRoot out

I try to solve the following system but I had the error message. ...
0
votes
0answers
35 views

Conducting mathematical operations without specifying functions

How should I define my functions without entering their exact expression so as to compute operations like differentiation on them? Say I have a function $f(t,x)$, which I don't want to specify. Now I ...
3
votes
3answers
93 views

Efficient function for life duration probability?

Sent to me by a colleague asking me for assistance (the function as is breaks): ...
3
votes
2answers
60 views

Is it possible to call Windows API function to Read/Write INI file directly?

I want to create a function to read or wirte windows *.ini files, so I plant to call GetPrivateProfileString and ...
0
votes
0answers
18 views

Slider controls not showing in CDF deployed to wolfram cloud

When I run my CDF from CDF player for instance, I my slider controls (fast forward, play, pause, etc) are initially visible using the following line of code within my manipulate: Appearance->"Open" ...
3
votes
1answer
31 views

Set the same box width for BoxWhiskerChart

I would like to use the same box width for two different plot. consider following example. How can I use the same box width for the second plot? ...
1
vote
0answers
36 views

Making a function $ f(n) $ tangential to another function $ g(n) $ by choosing appropriate constants

I have two functions $ f(n) = 1/(1+n) + b, (n \geq 0,b \geq 0) $ and $ g(n) = pn^2 + qn + r $. Assuming that I know the value of $ p, q $, and $ r $, I am trying to find a value for the constant $ b $ ...
1
vote
1answer
25 views

Font in graphics changes when saving as pdf in Mathematica 11

Consider a simple plot with text: Show[Plot[x^2, {x, 0, 10}], Graphics[Text[Style["some text", Large], {4, 10}]]] You can see Mathematica's output on the left ...
0
votes
1answer
35 views

Graphing from a file

I have a lot experience with traditional programming languages, but almost none with mathematica. I have data that I've transformed and saved to a file in the format {x,y,time} {x,y,time} ... ...
2
votes
1answer
46 views

How to Text justify that includes StringSplit and MapAt in it?

I am preparing a practical class of physics in which I need to justify the following text that is very extensive. But when I use StringSplit or ...
0
votes
0answers
57 views

Why doesn't Dynamic update if it only contains a Set statement? [strict]

Consider the 3 following manually entered evaluations where a Set statement is brought to the Front-End by Dynamic: Obviously ...

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