5
votes
1answer
135 views

Transcritical Bifurcation phase portraits

An example equation for a Transcritical Bifurcations is given by: $$\dfrac{dx}{dt} = f(x, r) = r x - x^2$$ In Mathematica, we can define the function as: ...
2
votes
1answer
64 views

Why does NDSolve and NIntegrate not give the same result?

I have plotted solution of two equivalent equations one in Integral form (right chart) the other in Differential form (left chart) using NDSolve and NIntegrate but they give me completely different ...
1
vote
1answer
179 views

Finding Coordinates of a Peak on a Plot

I have plotted a graph from a CSV file which consists of two columns of data Time and Intensity. I simply want to find the time where the intensity is largest. This code: ...
3
votes
1answer
451 views

Gâteaux (directional) derivatives and higher order differentials of a functional

I would like to calculate the Gâteaux derivative of a functional (i.e. a function depending on functions). A simple example for the Dirichlet functional: $L(u(x))=\int_0^1 \frac{1}{2} (u'(x))^2 dx$ ...
14
votes
2answers
573 views

Pulsed NMR animation

I'm new here and have never interacted with the community so excuse me if this has been asked before or if I format incorrectly or anything like that. Anyway, I'm trying to make an animation for a ...
3
votes
3answers
193 views

How to get exact coordinate of a point from a plot?

I am using BodePlot[] to plot the magnitude and phase of a function as below. BodePlot[1000/((1 + s/10^3)*(1 + s/10^6))] ...
26
votes
5answers
2k views

Fetching data from HTML source

I want to generate a couple of plots/graphs with Area 51 statistics. Since Area 51 doesn't work with the SE API, I'm forced to find another way to get the information I want. That other way is with ...
2
votes
3answers
146 views

Plots without axes labeling [duplicate]

I need to plot in Mathematica without labeling. For example, this code: ...
2
votes
1answer
112 views

Plot with two LabelStyle

I need to plot a graph using two different colors for the axis labels. Not working example: ...
1
vote
5answers
132 views

How find constant term of quadratic with square already completed?

Suppose I have a quadratic polynomial in two variables x and y in which the squares with respect to ...
6
votes
1answer
103 views

Filters on image vs data

I was using GaussianFilter and realized that applying it to an array yields a different result from applying it to an image. For instance: ...
1
vote
0answers
50 views

NDSolve returns solution with single point domain

Thanks to helpful comments from Michael E2 and George2079, I was able to focus in on exactly the source of the issue. With some simplification, I can reduce the problem to: ...
2
votes
1answer
82 views

replacement rule doesn't work

I define a function which counts the number of negative elements in a list as follows: g[x1_, x2_] := Count[{x1, x2}, _?Negative] Plugging in values shows that ...
0
votes
0answers
39 views

Testing if a character is a whitespace [on hold]

Is it possible to define a function which returns true if its only argument is a whitespace character (space, tab, newline, ecc...), false otherwise? I tried with various testing functions on the ...
2
votes
1answer
64 views

Extended AutoCorrelation Function

Is there a function in Mathematica capable of computing the sample Extended AutoCorrelation Function (EACF)? I know that there's a package in R that does this. I was trying to avoid to having to ...
10
votes
2answers
725 views

Why is Mathematica destroying this graph?

Here I have a picture of a function I graphed: reg[x_,y_]:=(x^2+y^2)Cos[4ArcTan[y/x]]; Plot3D[reg[x,y],{x,-2,2},{y,-2,2},AxesLabel->Automatic] And here is ...
0
votes
0answers
35 views

Create a loop for assignment of Solve output [duplicate]

Is there a way to automatically assign the output of solve to a number of symbols? For example, assume that I have the solve statement as follows: ...
0
votes
1answer
74 views

Get wrong coordinate in plot [on hold]

I am having problem with getting the coordinate of points on the plot below. The plot is OK but when I press Ctr + D and move cursor along the line, the coordinates are total wrong? Could you help ...
0
votes
0answers
46 views

Minimize variable domain neither real nor integer [on hold]

In Mathematica, can I have a variable domain something like x ∈ {1, 1/k}, where k is a constant? In my problem formulation ...
2
votes
1answer
31 views

Scaling HSB colors for export

In Mathematica, Hue[h,s,b] uses HSB colors. However, unlike anything I've ever seen, the h, ...
1
vote
1answer
52 views

How can use Table for two functions obtained from NDSolve? [on hold]

I have obtained a numerical solution using NDSolve for two functions a(x) and b(x). how do I use Table to make a list of a(x) vs b(x) values. is it simply Table[{a(x),b(x)},{x,0,100}] or should I use ...
-1
votes
0answers
30 views

Insert several sequential alphanumeric characters pdf [on hold]

As I can make it through "this" directory 1 to "this" in the directory 2 and so on for 50 pdf, Deputy sample directory Example
1
vote
1answer
129 views

Setting `ChartLabels` in a histogram

I have two data sets that I use to build a histogram in the following code: ...
6
votes
4answers
160 views

Searching a phrase in all *.nb files

I have so many *.nb files in a folder. In one of them I have written a phrase, unfortunately I cannot remember that file. I am searching about it and the file in ...
2
votes
1answer
118 views

Fractal plotting for the Collatz fractal

I have the following equation: f[z_] := 1/4 (2 + 7 z - (2 + 5 z) Cos[Pi*z]) I want to map this on the imaginary plane such that if it converges under iterations ...
9
votes
4answers
458 views

Numerical instability in cosh and sinh - integral functions [duplicate]

I'm trying to calculate the function: CoshIntegral[x] Sinh[x] - Cosh[x] SinhIntegral[x] Unfortunately Mathematica seems to hit a point (x~20) and things become ...
5
votes
2answers
244 views

Strange phenomenon occurring in analytic integration result involving Bessel functions

For the following integral, Integrate[x^2 Exp[-a x^2 - b x^4], {x, -∞, ∞}, Assumptions -> {a > 0, b > 0}] Mathematica gives the following analytic ...
1
vote
0answers
34 views

Quits Kernel during evaluation of CreateTopologies

I am using Feynarts 3.9 and FeynCalc 9.0.1 with Mathematica 10. Every time I load FeynArts with FeynCalc and execute t = CreateTopologies[1, 1 -> 2]; ...
72
votes
3answers
3k views

Flatten command: matrix as second argument

One thing I could never wrap my head around is how Flatten works when provided with a matrix as the second argument, and the Mathematica help isn't particularly ...
3
votes
3answers
166 views

Looking for a better way to delete an arbitrary list of rows from a matrix

Delete is not suitable to delete the rows of a matrix, as illustrated below: ...
0
votes
0answers
3 views

Query about hyperplane in SVM [migrated]

I am a beginner in Machine Learning. I was reading through basics of SVM and read this definition: The goal of a support vector machine is to find the optimal separating hyperplane which ...
1
vote
1answer
54 views

FindMinimum step size too small

I'm running a simulation of an electromagnetic system using Radia, an external code that is run from Mathematica. I want to use FindMinimum to determine some ...
9
votes
1answer
2k views

How best to embed various cell groups into a $\LaTeX$ project?

I'm an author and a coder. I want to reference various parts of my notebooks in my $\LaTeX$ project. I've tried doing the following, using a post on the $\LaTeX$ side of this problem. I'd like to ...
5
votes
2answers
236 views

ParametricPlot3D of Boy's surface

I'm trying to visualize Boy's surface using Bryant's parametrization, as per the MathWorld article. However, I'm not sure I understand the parametrization, and I don't know how to implement it when ...
2
votes
1answer
358 views

How to export figures with normal spacing in texts?

My OS is Ubuntu 14.04, and I use MMA 10. I export a figure ploted in MMA to a pdf file and then import the pdf in Latex, here is the sreenshot As you can see, the spacing in the text is odd. But ...
3
votes
2answers
229 views

Mathematica Interpolation or approximation

I have lists of points X and Y. {1212,1216,1217,1219...}, {1,2,3,4,5,6...} I combine ...
4
votes
1answer
90 views

UseFrontEnd is not working the same in version 10.4

I'm using batch files to run Mathematica notebooks (with saved output) but in version 10.4 the functionality has changed. Any ideas how to get it working? I use a batch file to run a .m script which ...
2
votes
1answer
56 views

Starting notebook from text mode

I am trying to start new notebook from a command line mode with command UsingFrontEnd@CreateDocument[] The notebook is created but it stays in minimized mode at the ...
1
vote
2answers
62 views

Plotting the InterpolatingFunction from NDSolve [on hold]

I want to plot the solution of a differential equation which i solve it numerically with NDSolve. Here's the code: ...
1
vote
1answer
32 views

How do you make y-axis labels and Ticks bigger in a BoxWhiskerChart

I'm trying to do a BoxWhiskerChart in Mathematica with a very specific Style. Specifically, I'm trying to get the y-axis labels (the numbers) to be bigger (point ...
0
votes
0answers
32 views

FindSpanningTree command doesn't work

I want to solve a network analysis problem by FindSpanningTree command. But it yields nothing: FindSpanningTree[G1] ...
2
votes
0answers
28 views
2
votes
1answer
54 views

How to plot a function whose constant parameters have associated uncertainties in Mathematica 8.0?

Let's assume I want to plot the function $f(x)=a + bx+ cx^{2}$, where experimentally known values of parameters $a, b$ and, $c$ are as follows: $a=1.01 \pm 0.18$ $b=0.92 \pm 0.11$ $c=2.2 \pm 0.2$ ...
0
votes
1answer
227 views

Asymptotic forms of Bessel function

I want to replace Bessel functions by asymptotic forms, so the question is: can I find the best ones with help of Mathematica? And if it's possible, how can I do it? Update How can I get with ...
5
votes
0answers
109 views

MacDonald formula for Modified Bessel Functions

How can I make Mathematica understand these two integrals? $$\int_0^{\infty} e^{-x \cosh{\xi}} d\xi = K_0(x)$$ $$\int_0^{\infty} e^{-\frac{1}{2} \Big( \frac{x y}{u} + u \frac{x^2+y^2}{x y} \Big) } ...
5
votes
0answers
53 views

Inconsistent performance of code

I'm trying to do some optimizations to my code to make it run faster, but it seems that there are inconsistencies in the performance of the code. Namely, the codes have different performance in ...
5
votes
1answer
74 views

Visualize Pascal's triangle with the product of the terms in the $n$th row

How to make the following graphics by using Mathematica? What I tried: I used J.M's answer for the Pascal triangle ...
0
votes
0answers
42 views

Using MemberQ or Contains* in a query fails

Using MemberQ or Contains* in a query fails: ...
1
vote
3answers
121 views

Basic Programming in Mathematica - How to build a loop [on hold]

I want to build a loop with the following rules: I have a list a={5,7,8,9,5,6,8,6,7,8}. I want to print the mean of the first two ...

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