0
votes
4answers
45 views

Matching a Table and a List and building a new Table

I have a Table which includes {Numbers, Probabilities}. For example A= {{1,0.5},{2,0.25}, {3,0.1},{4,0.9}……{100,0.1}}. Put attention that the numbers are 1,2….100 in order. I have a List of random ...
1
vote
1answer
67 views

Plotting a convex hull with a coordinate mesh

I am plotting the convex hull of some curves by extracting the curves from a contour plot and constructing the convex hull around their discretized version . It's not terribly accurate for ...
1
vote
1answer
51 views

Using Mathematica to batch-produce text files

I need to make a bunch of plaintext files, all of which differ only in a single parameter. The text I want to "copy" or "batch produce" is a little bit complex, since it contains quoted areas and ...
0
votes
1answer
31 views
0
votes
0answers
20 views

Make an existing solution for monitoring parallel jobs robust against dying kernels

Is there any chance to make the solution by @David here http://mathematica.stackexchange.com/a/1562/21606 more robust in the following sense: In my case, some parallel kernels die regularly during ...
9
votes
1answer
183 views

Odd Coloring with GeoRegionValuePlot

Bug introduced in 10.0 and persisting through 10.3 or later Bug behavior is version dependent When I'm plotting data with GeoRegionValuePlot, I'm getting some ...
0
votes
0answers
25 views

Setting Initial Conditions in a System of Differential Equations that don't start at t=0

I have a system of six differential equations (linear for the sake of the discussion). I want to set the initial condition to start at time t=18 and not time t=0. I know the values of the dependent ...
4
votes
2answers
223 views

How do I encode this replacement rule?

I'm pulling a 5x5 array from a larger array. The small sub-array (call it S) can contain any combination of the symbols A, B or 0. What I'd like to do is: if the array contains any matching pairs ...
7
votes
0answers
48 views

CopyToClipboard freezes FrontEnd

This is freezing the FrontEnd: CopyToClipboard@ExampleData[{"Text", "AeneidEnglish"}] Are there system limits I'm hitting here?
0
votes
0answers
23 views

Solving Time-Dependent PDE's Analytically with no non-trivial Boundary Conditions

I'm having some trouble solving a partial differential equation that is supposed to model the propagation of a scalar field in Schwarzschild spacetime using spherical coordinates. I'm using the DSolve ...
1
vote
2answers
46 views

How to find intersection points of linear and semi-logarithmic plots

Hopefully the title depicts what I am trying to do. Below is a figure of my calculations that is shown in logarithmic scale in the x-axis. I am trying to find a way to find the intersection point at ...
0
votes
0answers
29 views

A function for replacment in mathematica [on hold]

when you have too many replacements such as a1 x+ b2y + c1 z/.{a1->s^2+b^2,b1->r^2+g^2,c1->f^2+k^2} is it possible to define a vector like this ...
-2
votes
0answers
24 views
5
votes
0answers
40 views

How to find the concave points of a point-set?

To solve the boundary of a set of planar geometry, I sampled $6$ graphs, then using RunnyKine's approach. ...
2
votes
0answers
42 views

Why can Mathematica compute numerical sums more efficiently when they are written as matrix operations?

Let $f(n)$ and $K(n,m)$ be functions such that the double sum, which we wish to evaluate numerically, $$ \sum_{n=1}^a \sum_{m=1}^a f(n) f(m) K(n,m) $$ exists when $a$ is some large positive number. I ...
5
votes
3answers
243 views

Complex limit gives wrong answer

I'm evaluating $$\lim_{z\to e^{i \pi/2 n}} \frac{z-e^{i \pi/2 n}}{z^{2 n}+1}$$ with Mathematica 9.0.1: ...
5
votes
0answers
27 views

EventLocator in NDSolve seemingly hogs memory in Windows, but not Mac

I have written a function (ftest in my code) which does the following: Takes a vector {x,vx,vy} as input Numerically solves (with high precision) a specific ...
2
votes
1answer
60 views

Is it possible to find the close form solution of following Recurrence relation using Mathematica?

Example 1 F(0,t)=t F(n+1,t)=F(n,2*t) Example 2 F(0,y,t)=t F(n+1,y,t)=F(n,y+1,t*y) When I tried to manually solve above ...
9
votes
2answers
159 views

List of Recently Opened Files

If I go to the menu bar and press File I get a list of recently opened files.This would be useful except they are edited and mostly replaced by dots thus making choosing difficult. See the screen shot ...
2
votes
1answer
66 views

What's the easiest way to find the closest point in a list of pairs?

I frequently end up in this situation. I have a solution, but I suspect it's the dumbest way of doing it. Frequently, I'll have a list of pairs, for example: ...
0
votes
0answers
54 views

Learning Mathematica for Math Majors [duplicate]

I just downloaded Mathematica and I'm taking a course in Multivariable Calculus. I realize there is a lot of complexity to Mathematica and there are Many types of learning resources out there. I was ...
0
votes
0answers
34 views
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 ...
-4
votes
1answer
58 views

what is wrong with this plotting code? [on hold]

Heres the question: The region bounded by f(x) = x+2 and g(x) = sin(x) between x = 0 and x = Pi/2 i. Plot the region on the interval [0,Pi/2], between y = 0 and y = 4. ii. Find the area of the ...
1
vote
1answer
39 views

NRoots Results: From Equations to List of Root Values [on hold]

When I use Roots/NRoots, I get a disjunction of conditions as result. The conditions are normally of the type x == value How can I convert this to the list of root values?
1
vote
2answers
69 views

Write list of strings to a file (as lines)?

I have a list of Strings, like: list = {"hello", "world", "other line"}; And I want to write it to a file, so that each item in ...
2
votes
1answer
65 views

Prevent evaluation after ToExpression

How can I produce both typesetting and evaluation of a LaTeX expression? Illustrative example: The evaluation of HoldForm[Sqrt[2.0]] == Sqrt[2.0] looks ok (aside ...
0
votes
0answers
54 views
5
votes
3answers
282 views

How do I split a list of numbers to monotonic sequences?

Suppose I have: list = {1, 2, 4, 5, 7, 11, 8, 7, 3, 1, -3, -2, 6, 7, 80} And I want to split it to: ...
1
vote
0answers
42 views

Change “ListPlot” to 16 bit accuracy? [on hold]

I have (with the help of this forum) managed to plot a bifurcation diagram with the following code: ...
18
votes
2answers
541 views

Where can I get detailed information on how the Plot command works?

The command Plot[x^2, {x, -3, 3}, PlotStyle -> Arrowheads[{-.025, .025}]] /.Line -> Arrow produces this output. What I don't understand is what ...
5
votes
0answers
59 views

Huge difference after changing a fraction to decimal

I have a limit to calculate. With[{p = 1/2, q = 0.1}, Limit[a^q Integrate[Sin[x]/x^p, {x, a, Infinity}], a -> Infinity]] gives correct result ...
3
votes
2answers
233 views

Extracting RGB color code from a plot

I have let Mathematica to draw a plot of some functions written as below: ...
1
vote
1answer
45 views

Define a 4d matrix without for loop

I was wondering if there is a way to avoid for loop here: I want to define a 4d matrix H(i,j,k,l), and each entry in the matrix is calculated through a complex function, say Do_H(i,j,k,l), depending ...
2
votes
0answers
26 views

FindPeaks error “ Expecting an image or graphics instead of”

I'm running Mathematica 10.3.1.0 on windows 7 Professional Sp.1 when I try to use FindPeaks I keep getting the following error, even when trying the example in the ...
0
votes
1answer
72 views

Why are CoefficientRules and MonomialList so slow?

Why is CoefficientRules so slow in this example (v10.2 on OS X 10.11.4)? ...
0
votes
0answers
19 views

How to derive natural boundary conditions and governing equations by Mathematica

I can derive governing equations of system by Variational Package of Mathematica but it doesn't give boundary conditions. How can i get them? or is there another way (such as another software) to do ...
0
votes
0answers
37 views

NDSolve won't stop running

I'm trying to solve the wave equation with NDSolve, but everytime I hit evaluate notebook it won't stop running. Any insights? ...
2
votes
1answer
50 views
0
votes
0answers
25 views

Time and distance problem [on hold]

A train starts from Jammu for Srinagar at 13:30 and reaches Srinagar at 17:30. Another train starts from Srinagar at 15:30 and reaches Jammu at 19:00. At what time will the trains meet?. I have ...
2
votes
0answers
66 views

Wrong limit involving sine?

Using Mathematica 9.0.0.0, I was trying to calculate the sum $$ B_n = \sum_{i=1}^n \sin^4\left(\frac{(i-1)}{(n-1)}\cdot\frac{\pi}{2}\right). $$ where I thought it would be $B_n = \frac{3(n-1) + ...
1
vote
0answers
35 views

axis label problem

I have a contourplot with (Greek) omega on the y-axis and Q^2 (GeV^2) on the x-axis. When I do ...
6
votes
3answers
417 views

Partition a disk into regions based on points on a circle

I am plotting the roots of a polynomial on the unite circle this way ...
4
votes
1answer
45 views

To embed metadata in a notebook, keeping them both human readable and easily parsable

I' m trying to set up a gizmo to manage the large notebooks collection, in my Mathematica workspace. The main idea is to embed indexing metadata in each notebook and manage them by means of function ...
2
votes
1answer
70 views

Mathematica built-in function that translates number strings to numbers

I recently ran across a function in mathematica that translates "twenty-two" to 22, but I can not remember what it is and my searching through the help functions has yielded nothing. Can anybody help? ...
1
vote
1answer
54 views

How to convert Image3D object into Graphics3D object and vice versa?

There are some rendering options (for example, Lighting) which are associated with the Graphics3D objects. I cannot apply these ...
1
vote
1answer
39 views

Specify the color of each residue in a protein (PDB)?

I'm importing a .pdb file containing a single protein. Mathematica automatically produces a plot of the protein. I want to specify the color of each residue independently, in this plot. Is this ...
2
votes
0answers
88 views

Integrate producing bad result

I noticed a bug in Mathematica. It computes incorrectly a definite integral ...
0
votes
1answer
72 views

How to find roots using the bisection method

First I plot the function and then I try to find a domain such that I can see the curve cut through the x-axis. I do this via trial and error ...
2
votes
2answers
56 views

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