3
votes
2answers
88 views

Switching Differential Equation in NDSolve

I am trying to solve the following system of differential equations using NDSolve: $\dot{z}_t=.5(1-z_t)$ $\dot{y}_t=.05y_t+z_t-x_t$ subject to the following constraint: $-y_t-z_t\le0$ where $z_t$ ...
6
votes
1answer
109 views

Left Right Straight Maze

How do I generate a Left, Right and Straight ordering for a maze for something like the following? Similar to generating a left and right ordering for someone walking in real life. ...
4
votes
2answers
202 views

Calculate $\pi$ using Monte Carlo methods

I know that we can have an estimate of $\pi$ using Monte Carlo methods. I know that we make a huge loop and each time we take randomly two numbers in the range [0,1] and calculate the number of ...
0
votes
0answers
38 views

Construct certain univariate functions over bounded interval having given set of moments [migrated]

We have a class of probability distributions (parameterized by $\alpha =\frac{1}{2},1,\frac{3}{2},2,\ldots$) over the interval $[-2^{-12} \cdot 3^{-3},2^{-16}]$ having as their $n$-th moments ...
0
votes
2answers
83 views

I'm trying to solve a system of complex equations

I'm simply trying to solve a system of equations and mathematica can't do it for all values over the region of interest. I have a 3x3 matrix that has a specific parametrization and after squaring the ...
1
vote
1answer
75 views

Use Map on a Function with two variables

I am new to Mathematica and I would like to find out how to use Map on a function with two parameters such as: ...
1
vote
2answers
94 views

NSolve won't act on very large powers

I noticed that NSolve isn't running properly when I have some seemingly harmless numbers in my expression. Here is a simple example: ...
2
votes
2answers
55 views

Substituting within a function definition that includes Simplify

I would like to define a function like myfunc[f_] := Simplify[(f/g)] where g will be substituted/replaced with the current value of g at the time of definition. ...
3
votes
1answer
35 views

Show In/Out names in some notebooks but not others?

I often have a working notebook and a "publication notebook". Figures and results are copied to the publication notebook to which explanatory text is added. The publication notebook can then be saved ...
1
vote
2answers
51 views

Scale in plot and Piecewise

I wrote this code: ...
3
votes
1answer
66 views

Checking if input is a function

I would like to write a program to find the leading coefficient of a given polynomial. (Sounds easy, right?) I'd like to be able to handle the format x^2-x+7 (with ...
4
votes
3answers
252 views

Enforce monotonicity in a list

Suppose I have a list containing pairs of complex numbers. For example: ...
3
votes
2answers
88 views

RegionPlot with LogScale

I would like to have my RegionPlot with logarithmic scale in x and y. My code looks like ...
3
votes
3answers
166 views

Return a sentence with numerical values

I have the following function: example[a_, b_] := Module[{c}, c = a + b; Return["The solution is c"] ] I would like to know how to return that ...
0
votes
2answers
66 views

FindInstance function

I have a question concerning the FindInstance function. If I write FindInstance[c == 3, {c, l}] I obtain {{c -> 3, l -> 33/10 + (8 I)/5}} Is there any ...
6
votes
2answers
72 views

Annoying behavior of a dynamic angular gauge

I want to do something that can be simplified into the following toy example: I want to dynamically show the count down to a future date on an AngularGage. The ...
3
votes
0answers
46 views

JournalArticle does not react on the PointSize option

The Default StyleSheet recognizes the PointSize option for ListPlot: ...
3
votes
1answer
66 views

Problem with ComponentMeasurements and property “Centroid” [on hold]

I am showing here three test images to investigate the output of ComponentMeasurements when using the property "Centroid". ...
2
votes
1answer
69 views

issue with Animate

I want to make a animation based on the dataset like data = Flatten[Table[{x, y, x^2 - y^2}, {x, -3, 3}, {y, -3, 3}], 1]; I show this data using a ListPlot3D. ...
0
votes
0answers
59 views
2
votes
0answers
43 views

The correct assignment of probability distribution to generate random variables

I'm asking you for a help to solve a difficult (for myself) task. Now I will tell you what and why I'm trying to implement. The task is to simulate the passage of elementary particles through a ...
4
votes
0answers
42 views

Spell checking in German texts - strange behavior

This questions is about spell checking in German within Mathematica. I have encountered some strange behaviour of Mathematica's spell-checker. Words within the dictionary are sometimes marked as ...
1
vote
1answer
65 views

How to improve the smoothness of ContourPlot3D at the boundary

I want to ContourPlot3D[] a iso-surface. $3$ independent variable are α1, α2, Ψ, respectively. The codes are as follows (the ...
4
votes
1answer
138 views

Verifying the outputs of 'Solve'

I got a solution for the equation ...
1
vote
0answers
32 views

How to preview the notebook file in a file explorer just like the preview of pdf file

I use Mathematica for daliy small program and visualization, so I have many samll notebook files. I use long file name to tag and distinguish these files, but sometimes I use short file name (maybe ...
2
votes
1answer
64 views

Output short denominator as pre-factor

How can I make the output print like the input, with the short denominator written as a factor in front of the long expression? I was messing with styles earlier today to do something else, and at ...
7
votes
1answer
114 views

ClipPlanes crashed in V10.4

In Mathematica 10, a very useful Graphics3D[] option ClipPlanes was introdued. ...
3
votes
1answer
130 views

How to guarantee the point's position is fixed in the Graphics and Image

SeedRandom[8] plot = ParametricPlot[ Evaluate@BezierFunction[temPoint = RandomReal[{-50, 50}, {5, 2}]][ t], {t, 0, 1}, AxesOrigin -> {0, 0}] We can ...
-1
votes
0answers
26 views

Reasons for the sign differences [closed]

While numerically evaluating certain definite integrals, many a times Mathematica gives correct values, but sometimes if we change the parameters, then the answer is just the negative of the original ...
3
votes
1answer
89 views

Getting PlotPoints value from a Plot

I want to display the PlotPoints and MaxRecursion values used to plot the current graph so that the user can change the values ...
0
votes
0answers
62 views

Is there a good way to schematically show that 3 vectors are perpendicular?

I have 3 vector plots, I want to show that overlapping arrows from each plot are perpendicular to each other, when I show all plots in one plot it looks like this: It is hard to see that the ...
10
votes
1answer
178 views

NDEigensystem cannot solve numerically the 3D Coulomb problem, while DSolve returns the right answer

After having derived by hand the eigenvalues and eigenfunctions for the 3D and 2D hydrogen atom, I want to solve the systems numerically using Mathematica. I need to do this because my next step is to ...
0
votes
1answer
61 views

Where is the file Default.nb?

I've found a couple of files called Default.nb under my Mathematica installation, but they don't seem to have any effect. At any rate, neither of them was changed when I edited 1 the so-called ...
-2
votes
0answers
31 views

How can I fit two datasets with common fit parameters? [closed]

I have two datasets, say data1 and data2, which can be modeled by the functions f1[params__] ...
-5
votes
1answer
33 views

Getting SetDelayed::error from Solve [on hold]

I defied three functions as following: f1 = a1 x1 +a2 x2 + a3 x3 f2 = b1 x1 +b2 x2 + b3 x3 f3 = c1 x1 +c2 x2 + c3 x3 and I wrote ...
-2
votes
0answers
39 views

Finding Laplace Transform [on hold]

With the following DE y"(t)+5 y'(t) +6y(t)= t 0 How do I find the Laplace Transform to find the IVP??? I've tried everything and I can't figure it out.
-1
votes
1answer
38 views

Solve returns empty list on system of 62 linear equations with undeclared known variables

Context: I am trying to solve a set of equations generated by hand from a complicated, but not particularly strange system via Newton's Second and Third Laws, and a few constraints. All the resulting ...
1
vote
1answer
81 views

NIntegrate gives two results for two forms of the same function. Which one to trust?

I am interested in evaluation the following integral numerically (since apparently there is no analytical solution) $$\int dx \,x^3 \left(e^{2 i c x }-i \text{erfi}\left(\frac{x +i c ...
2
votes
1answer
39 views

What function superseded SpaceForm?

In older versions of Mathematica you could use SpaceForm to leave a certain amount of spaces when writing to a file. For example, if we have the following data: ...
1
vote
3answers
298 views
+100

Matching the order of a master list of lists from a random list of lists

Using Mathematica 9, I have 2 lists of lists one master with dimensions {300, 6}. The second is some random order but has the same first ...
3
votes
2answers
79 views

Assigning Element Markers to 3D FEM Mesh

I have created a 3D graphic using GraphicsComplex and then use ToElementMesh to generate a 3D Mesh that I want to solve a PDE on, but I cannot figure out how to apply ElementMarkers to the Boundaries. ...
2
votes
1answer
46 views

Small glitch with EdgeForm and PlotRange

I'm experiencing a small problem with the edges of a square, if the PlotRange has the same size as the square : ...
0
votes
0answers
32 views

Inverse Fourier Transform [migrated]

I have to calculate the following Inverse Fourier-Transform, which describe the potential function for a point force on a half-space: ...
1
vote
2answers
58 views

How to emit sound of specified frequency for a specified amount of time?

Sorry but I am confused by several sound/play commands in Mathematica. What I want to do is to emit a succession of sounds according to a succession of frequencies and durations. Specifying timbres ...
5
votes
0answers
31 views

How to trace the stylesheet directives responsible for the selected text's appearance?

By way of example, in a typical Mathematica interactive session, one sees text content as shown below: Three different text styles can be seen in this figure: input, output, and the style for the ...
6
votes
2answers
96 views

How to generate higher dimensional convex hull?

I like the function ConvexHullMesh very much, since I often need to take a look at the convex hull of points in 2D and 3D, which as an example can be generated and ...
1
vote
1answer
19 views

Delete Cell Inside of Module

I want to print a dynamic output while some code is running and then automatically delete it when when the output is done. PrintTemporary is not quite what I am looking for -- I want the output to be ...
3
votes
0answers
34 views

How to make use of multithread feature of Eigenvalues in ParallelDo or ParallelTable [duplicate]

In mathematica, Eigenvalues is implemented internally using intel MKL. When running Eigenvalues[RandomReal[1.,{2000,2000}] ...
3
votes
2answers
166 views

Solving coupled differential equations with unknown constants

Is it possible to obtain exact solutions of these types of coupled differential equations directly in Mathematica ...
3
votes
0answers
24 views

How do I get my ZWO ASI120MM astro-camera to work in MMA?

I am using Windows 10 + MMA 10.4.1. I bought a ZWO ASI120MM astro camera which I want to use as a guiding camera during astrophotography. From this site (http://astronomy-imaging-camera.com/software/) ...

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