0
votes
0answers
3 views

Equality of Reciprocal with Negative Exponent

I want MMA to tell me if two, rather large, expressions are equal. My minimum working example follows. I want MMA to tell me that the following is true:$$x^n = \left(\frac{1}{x}\right)^n$$ I have ...
4
votes
3answers
76 views

ImplicitRegion gives arbitrary boundaries

This question uses Mathematica 10.2.0.0. equation1 is the major unbounded region I would like to generate: ...
11
votes
1answer
144 views

FullSimplify wrongly reduces expression to zero

Bug introduced in 9.0 and persisting through 10.2 or later I get the following output with a fresh Mathematica (ver 10.0.2.0 on Mac) session ...
0
votes
0answers
12 views

How to get a region to an element mesh? (E.g. ToElementMesh[R], but doesn't seem to work.)

ers, I've been exploring a new 3D solid commonly called the "Chestahedron" (7 faces of equal area). I wanted to find the centroid, so turned to Mathematica... and found it!:) Other things of interest ...
6
votes
2answers
212 views

How to simplify only the lowest level of a nested expression

I have a large expression that takes forever to simplify if I apply FullSimplify[...]. The expression has lots and lots of brackets that luckily already groups ...
2
votes
0answers
20 views

Clean & efficient bounding box non-intersection test

I would like a quick test to tell me that segments $ab$ and $cd$ cannot intersect in the plane. If the maximum $x$-coordinate of $a$ and $b$ is less than the minimum $x$-coordinate of $c$ and $d$, ...
3
votes
1answer
57 views

How should I iteratively refine a MixtureDistribution?

I am trying to find a stopping time for a randomized simulation such that say 95% of trials that will be successful will have already finished. I would like to do this by creating and then refining ...
10
votes
4answers
364 views

Mathematica complaints that convergent integral diverges

Bug introduced in 10.0 and fixed in 10.0.2 Trying to do the integral ...
7
votes
1answer
243 views

Problem with Neumann condition in quarter disc

Bug introduced in 10.0 and fixed in 10.2 So I'm following the available examples in version 10 for FEM, The plane stress operator is shown as this ...
17
votes
2answers
567 views

Why is TextString[-0.5] a positive number?

Bug introduced in 10.0 and fixed in 10.0.2 I want to format numbers in decimal notation and chose TextString for this task. But today, when looking at the final ...
3
votes
1answer
145 views

How to make sure polygon is drawn flat in 3D?

Bug introduced in 9.0 or earlier and persisting through 10.2 or later I'm working on this SE question about pentagrams on top of dodecahedron for exercising. Both solutions are basically connecting ...
4
votes
2answers
53 views

redefining a built-in operator

Is there a way I can redefine the || operator such that a||b will be 1/(1/a + 1/b)? Is it ...
6
votes
3answers
103 views

Difficulty using LUDecomposition

I'm having trouble using LUDecomposition with pivoting. I read the Mathematica help on this particular command, but I'm still lost. Take a matrix like: ...
0
votes
0answers
29 views

Once working code fails upon restarting Mathematica [on hold]

I had a code which worked flawlessly, then upon shutting down mathematica and re-starting it, the code failed with the following error message: "The function value -Abs[f[0.0228659,I/6]] is not a ...
0
votes
0answers
24 views

choosing the number of points in FindFit function [on hold]

I am trying to find the best function to fit a set of data as following, ...
0
votes
0answers
9 views

Probability Quesiton Help [migrated]

I am working on some exercise questions from probability. I am stuck at this question. Can somebody help me to solve this. I would really appreciate. In a certain country, 35 percent of people are ...
0
votes
0answers
4 views

How to write this Google docs, percentage calculation function? [migrated]

I track my diet (macros) in Google docs. For 1 day my protein is 114.63 carbs 194.75 and fat ...
0
votes
0answers
20 views

Hook Length Formula and Ferrer's Diagram

So, I am new to using Mathematica, and trying to write some code that needs to use hook length of each cell in Ferrer's diagram of a partition. I first thought of using for loops to manually count ...
2
votes
1answer
106 views

Dirichlet convolution of two lists [closed]

The Dirichlet convolution of two arithmetic functions f,g is defined by $f\ast g(n) = \sum\limits_{d|n} f(d)\ast g(n/d)$ How can I get the Dirichlet convolution of two lists? For example: Input: ...
0
votes
0answers
34 views

How to simulate a homogeneous nucleation?

From this topic Animating a Voronoi Diagram I can simulate the heterogeneous nucleation. Based on the voronoi Diagram, How can I use Mathematica to simulate the homogeneous nucleation?
-3
votes
0answers
40 views

I want a mix matrix

I have a matrix with dimension (m, n) and elements f[p,q] and a matrix with dimension (i, j) and elements g[r,s]. How can I make a matrix (m+i) by (n+j) with elements Table[f[p,q],g[r,s]]?
4
votes
1answer
50 views

code is ignoring WhenEvent

I would like the value of x[t] to be equal to 0 when it has a negative value so I used WhenEvent but it has no effect on my code ...
4
votes
1answer
44 views

InstallJava on a parallel kernel while debugging in Wolfram Workbench

Here's my problem. I need to create a link between a client that is a parallel Wolfram kernel and a server through a Java API. I'm using Wolfram Workbench in debugging mode (like most of the time ...
8
votes
3answers
356 views

Calculating integral by Romberg Algorithm

In my "Numeric Anasyis" course, I learned the Romberg Alogrithm to calculate the numerical integral. The Romberg Alogrithm as shown below: $$ ...
0
votes
0answers
37 views

Is there a way to pre-calculate a slow animation and then run easily with no lag? [duplicate]

I have an animation of a triple pendulum on a moving base, however even after trying to change the whole coding to make it faster by using module and all it is still pretty bad as I need it to be ...
3
votes
1answer
317 views

How to embed a Mathematica demonstration in Google sites?

I want to have students submit articles that include Mathematica demonstration projects in a document that is on Google sites. I am having problems with embedding the JS code. Could you provide ...
22
votes
8answers
5k views

About multi-root search in Mathematica for transcendental equations

I have some questions for multiroot search for transcendental equations. Is there any clever solution to find all the roots for a transcendental equation in a specific range? Perhaps ...
5
votes
2answers
50 views

Labeling columns in grouped charts separately

I want to label sequentially some charts. Say, for instance, that I had: ...
1
vote
1answer
80 views

Saving numerical values to a *.dat file [on hold]

I have a function like this: F[m_, t_] = Sum[Sum[Q[[m,i]]*Q[[m,l]]*SS[t], {l, 2, Y}], {i, 2, Y}] How can I save values of this function to some ...
8
votes
0answers
55 views
7
votes
1answer
102 views

Eisenstein Series in Mathematica?

Mathematica doesn't seem to have built-in tools to deal with the Eisenstein Series: $E_{2}(\tau)= 1-24 \sum_{n=1}^{\infty} \frac{n e^{2 \pi i n \tau}}{1-e^{2 \pi i n \tau}}$ $E_{4}(\tau)= 1+240 ...
-2
votes
2answers
63 views

Error in the solving of the simultaneous Ordinary Differential Equation [on hold]

As I am trying to get the solution of the simultaneous ordinary differential equations ...
1
vote
1answer
285 views

Getting code from the Wolfram Demonstrations Projects [closed]

I saw from mathematica's website, there is a fantastic project about the 2D Riemann Sum. Riemann Sums For Functions of Two Variables I want to see the similar effect in my Mathematica (with ...
-1
votes
0answers
65 views
2
votes
2answers
135 views

Efficient List of Lists

I'm running some analysis that requires the creation, row by row, of a large list of lists. The big list is called "Nodes" and it will ultimately contain hundreds of thousands of rows. The first few ...
7
votes
2answers
139 views

Why is mathematica eating a row from QRDecompostion

I'm attempting to calculate the QRDecomposition of the matrix: a= {{1,3},{0,5},{2,-8}} QRDecomposition [a] The answer mathematica gives me is: - Q which is a ...
3
votes
2answers
100 views

Help with Integration

I am new to Mathematica, and I need help with integration of the following Reliability expression (from a well-known Reliability Model). $$R(t)=e^{-Ne^{-bt_i}(1-e^{-bt})}, t \geq 0$$ I have ...
4
votes
0answers
53 views

GeoProjection for astronomical data - wrong ticks

Here is an excellent answer to what I wanted to do, and it works like a charm. Unfortunately, when I want to change it a bit, it fails. For setting the stage, here is the datafile, and this is my ...
8
votes
2answers
1k views

Viewing Mathematica Demonstrations Project Code

I hope I am going insane and the I'm not seeing the snake about to bite me... How does one view the code in the demonstration projects that one can download from wolfram.com? It seems like all of ...
2
votes
1answer
122 views

Failed to create a special random-disturbed initial condition for partial differential equation

I try to use BSplineFunction to creat a initial condition for NDSolve which has periodic boundary condition, that is realized by ...
2
votes
1answer
118 views

Can I make a function which depends on several arguments which are not independent?

Here's a simple example Suppose have the permanent relation that z is proportional to xy^2, for real numbers s. z = s x y^2 Now, we are interested in ...
6
votes
2answers
130 views

Number of divisors visualized with the QPochhammer function, how improve performance of code?

I have this code that originally is Jeffrey Stopple's code for the Riemann zeta function in the complex plane. Because I discovered yesterday that the number of divisors can be generated with the ...
1
vote
2answers
61 views

How to find the same number in sublists of list

Intersection[Table[Table[Sqrt[p1]/r1,{r1,0.1,0.7,0.1}],{p1,0.5,5,0.5}]] I am trying to find same numbers in the sublists. But Intersection is not working for ...
1
vote
0answers
38 views

Funny behavior when computing dot product of coefficients with high-order polynomials

I have a similar problem to Funny behaviour when plotting a polynomial of high degree and large coefficients. However, the thing being evaluated is not just a polynomial but a dot product of some ...
6
votes
2answers
757 views

Mathematica 10 cannot solve definite integral

Bug introduced in 10.0 and fixed in 10.0.2 Mathematica 10 fails to solve the following integral, saying that it does not converge. ...
9
votes
1answer
722 views

NDSolve::ndcf: Repeated convergence test failure. How to solve?

I am trying to simulate a system of $n$ pendulums with some friction in Mathematica 9. This is the code I am using: ...
3
votes
1answer
189 views

CUDAFunctionload error

I am trying to get CUDAFunctionLoad to work with Mathematica 9.0. I installed the latest clang and the Nvidia Tools 6.0. but I keep getting the error message: ...
2
votes
0answers
31 views

Tree graph showing the orbits under the Collatz map?

ReverseCollatzPaths is a nice demonstration of a radial tree graph showing the orbits under the Collatz map. However, Jason Davies gives, I think, a nicer visulalization using Python, with a ...
9
votes
0answers
145 views

Behavior of TimelinePlot with multiple datasets of associations

Bug introduced in 10.1 and persisting through 10.2 or later The following TimelinePlot behaves as I would expect: ...

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