-1
votes
0answers
44 views

Solution To Nonlinear System [closed]

I have a solution for the following from Matlab's symbolic engine, but it is extremely long and ugly and will divide by zero if the coordinate system is oriented a certain way. I am hoping that ...
0
votes
1answer
96 views

predator prey model with prey refuge

I want to plot the phase diagram of prey predator versus prey refuge to see how the prey refuge influences the population of prey and predator.And this is the system $x'=\alpha ...
0
votes
1answer
41 views

Mathematica quits calculation automatically

I have this little program that is adopted from a Wolfram demonstrations project (link here: http://demonstrations.wolfram.com/PercolationOnASquareGrid/). I want to see what happen if I increase the ...
0
votes
1answer
58 views

Mathematica Compute Time Is Extremely Long (Integrate simple function with parameter scan)

I was wondering if you can help. I have a set of equations I need to solve for a list of parameters; entering each parameter value and solving anew each time is simply not economical. I found a way ...
-1
votes
0answers
31 views

Proper way to generate a higher order function with a proper scoping. [closed]

In the previous question I asked was Name scope confusion. The reason for the snippet in the above link was that I would like to construct a higher order function that returns a function depending ...
0
votes
0answers
37 views

Dynamic and Graphics3D crash in Ubuntu

Im running ubuntu 12.04 and sometimes mathematica 9.0 crashes when I have Dynamic Content or graphics 3d. I'm wondering if this has happened to anyone else? I wouldn't be surprised if this is a ...
3
votes
1answer
64 views

Why does Mathematica list the variables in a double integral backwards? [closed]

I am an advanced novice Mathematica user and have done a fair amount of single-variable calculus things with it. This semester I am using Mathematica for multi-variate calculus and when I tried to ...
1
vote
3answers
97 views

Plotting a frequency function

I have a list of numbers and I want to plot the fraction of numbers >= k against k which will naturally be a decreasing curve. How do I do that?
4
votes
1answer
171 views

Coloring a honeycomb structure

I am trying to generate a honeycomb structure. With the help of this MMA.SE question & this website, I got ...
0
votes
0answers
21 views

KernelObject::rdead on local kernels

I'm trying to parallelize some tasks which involve fetching data from a URL and processing it. This is the code: ...
1
vote
1answer
87 views

Help to solve the equation with RungeKutta method [closed]

I need to solve this equation. v'[t] + v[t] == 1/(1 + Exp[-v[t]]) I tried to solve it using RungeKutta method described in Wolfram ...
1
vote
0answers
31 views

Setting an initial value for ListAnimate?

ListAnimate is fairly similar to Manipulate, but while Manipulate has a simple way to request an initial value for the manipulation parameter, I haven't found a way to tell ListAnimate to start with a ...
3
votes
1answer
66 views

How can I get precise frame rates in dynamic?

I've been the Spritz sdk in my ios apps, and I love it. For funsies I wanted to see how much less code a mathematica version would take! Using dynamic I get a nice result, shown below in code. ...
0
votes
2answers
55 views

Are solid spherical harmonics implemented in Mathematica?

In certain applications, solid spherical harmonics can be very useful. They are essentially the usual, 'surface' spherical harmonics, with the appropriate power of the radius inserted: ...
2
votes
1answer
53 views

Package for representation of groups (group theory)

I wanted to know if there is a package which allows to compute representations of a group like the definition representation, adjoint and so on (for example the Pauli matrix for $SU(2)$ if I specify ...
0
votes
1answer
61 views

Creating If statements programmatically [duplicate]

I want to write an algorithm that returns a sequence of numbers, starting from a specified point but stopping once a criterion has been reached. For example ...
1
vote
0answers
25 views

How can I select two lists from a list of lists so that I receive the system of equations has only rational solutions?

I want to make a sytem of equations has the form $$\begin{cases} a_1x^2+b_1y^2 + c_1xy+d_1x + e_1y+3=0,\\ a_2x^2+b_2y^2 + c_2xy+d_2x + e_2y+3=0. \end{cases}$$ so that the given system of equations has ...
1
vote
1answer
58 views

Solve never terminates with simultaneous equation set

I have the following set of simultaneous equations that I want to solve symbolically. The two unknowns are $a$ and $d$. $a=\frac{c*(d/10)}{1 + (f/130) + (d/50)} - \frac{a}{1 + (a/100) + (d/100) + ...
0
votes
0answers
38 views

Solving a single equation with multiple parameters

If I wanted to solve equations like Cos[x]^2 = A Cos[Bx + C] + D what function should I use? The Solve function seems to only solve for as many variables as there are equations. Please note that my ...
0
votes
0answers
24 views

JacobiCN inaccuracy

For my calculations I need JacobiCN[s,k] for s near 0 from the left and k near 1 from the ...
0
votes
0answers
48 views

Can you help me to use MANIPULATE? [closed]

I don´t like this kind of questions, but... I can´t reach a good solution, so... I say "HELP"... If you close my post... I understand... and I say "Excuse me, I know that this is no pretty" I have ...
2
votes
1answer
75 views

Showing ListLogPlot and redrawing FrameTicks

I want to combine two ListLogPlot plots. For example ...
1
vote
1answer
38 views

Connecting to a SQL Server Instance

What is the syntax for connecting to a specific instance of a sql server database? Here's my code: ...
-1
votes
0answers
38 views

How should I use precision in this code?

I am writing a mathematica code where I have 19 parameters (m,EX1,DX1 and so on). To begin with a specific guess value is assigned to each parameter that I am updating within the loop. Now I am ...
0
votes
1answer
33 views

How do I keep my Animate running at high resolution?

I'm building an Animate where I have a 3D plot with some of its parameters changing: ...
-1
votes
1answer
66 views

MANIpulate. How to put labels and fit 24 vslides in a row? [closed]

How could I fit 24 vertical slides in a row?, in the up and How to add any reference like 0 and 8 ? and how to add 2 options boxes in the right under the vslides (or to the right of vlides??? What ...
0
votes
0answers
34 views

Fitting data involving units

I want to fit some data to a model. However, if the data involves units in the independent variable, fitting seems not to work. As an example, consider the code ...
0
votes
1answer
28 views

Generate array of every $n^{th}$ integer between two bounds [closed]

I want to generate the series {1930, 1934, 1938, ..., 2014} with Mathematica. I found that I can use Sum[2014-m*4, {m, 20}] to ...
7
votes
1answer
72 views

Equivalence under common permutations

I have lists which consists of sublists of equal length. The outer list is regarded as a multiset (that is, permutations of the sublists don't matter, but repetitions do), but the order in the ...
2
votes
1answer
142 views

Running a shell script within Mathematica

The title pretty much explains it and I have not found something similar already posted. Perhaps I am not searching for the correct title or maybe this is something very basic, but I would appreciate ...
0
votes
0answers
49 views

Putting a plot legend in the plot [closed]

I use the code below to put plot legends in the plot: ...
0
votes
1answer
56 views

Extract random points from a 3D manifold [closed]

Could anyone help me with this problem? I have a 3D manifold given by $$1<d<b<c,\;\;b+d<c,\;\;b+2d>c.$$ My goal is to find a lot of points belong to it.
1
vote
1answer
60 views

Mathematica does not respect tensor order?

I'm trying to verify an identity involving symmetric traceless tensors over the reals. What I tried was: ...
3
votes
2answers
66 views

Interpolation impossible for ListPlot with Missing?

I have a list of data to plot. I would like to plot them with lines but delete some data before plotting and leave the lines disconnected where data is deleted. For example, ...
3
votes
3answers
91 views

Name scope confusion

Sorry for the too ambiguous title. First consider a following code snippet. ...
0
votes
0answers
18 views

NMaximize not satisfying binary constraint

I'm solving an optimization problem in Mathematica with binary integer constraints. It works alright with other constraints. But the only problem is that both NMaximize and NArgMax are not treating ...
1
vote
1answer
40 views

Country borders and grids with CountryData plot?

I am coloring several countries in the manner of the following: ...
22
votes
9answers
3k views

Programming paradigm change

I'm new to Mathematica, I've been learning by myself, and, being a Java developer for some time, it makes it hard to adapt. I've tried to solve a Reddit challenge, and I came up with this solution: ...
0
votes
1answer
54 views

marking the points of x-intercept on a plot

OK, I have a nice plot of some oscillating motion. I can read some stuff off the graph, but I thought it would be cool to show a dot where the curve hits the x-axis and a little label showing the ...
0
votes
0answers
38 views

How to plot stacked curves with sharing the horizontal axis [duplicate]

How to plot the curves in the image.
1
vote
1answer
35 views

How do assign an interval of values to a variable in order to use them in a function?

From my code (below) I have K1 and K2 set to zero in order to test this numerical method. However, K1 is on an interval from 0 to 32, and K2 is on an interval from 0 to 8. I would like to know if ...
3
votes
2answers
39 views

Mathematica: Extract the piece that contains x=0 from within a piecewise function

In mathematica, I have a piecewise function similar to: Piecewise[{ {x^2 + 2*x - 4, 0 <= x <= 1/4}, {0, true} }] I don't ...
5
votes
2answers
59 views

RLink Java(TM) platform has stop working

I am trying to send to R a big function,it has only three variables but output is quite big.So when i "translate" that code from mathematica to look like R code and input it in REvaluate i get the ...
6
votes
3answers
187 views

Graphics in Notebook Different from Graphics Expression?

Consider the expression TreeForm[a+b^2+c^3+d] which displays as This is a nice Graphics object, as I can prove by typing ...
0
votes
0answers
6 views

T is an operator on inner space, how to prove T is invertible if and only if T* is invertible? [migrated]

T is an operator on an inner product space, how to prove T is invertible if and only if T* is invertible? Can I change the target to prove T is injective iff T* is injective?
3
votes
1answer
145 views

Converting truth tables to boolean expressions

I have a truth table for a Boolean expression represented like this ...
6
votes
1answer
124 views

Symbolic scalar-by-matrix derivative

Let's say I want to calculate the following scalar-by-matrix derivative $$\frac{\partial}{\partial A} \text{tr} \left[(\vec X^T A)^T (\vec X^T A)\right],$$ with $\vec X$ and $A$ being a $n \times 1$ ...
1
vote
1answer
87 views

A simple expression which Mathematica will not simplify

Sorry for the vague title, but I wasn't sure how to phrase this. I was using Mathematica to solve a fairly simple algebraic equation, but when I tried to substitute the solution into the original ...
-2
votes
1answer
67 views

How to put the labels in the minimun and maximun option in the slide verticals? Manipulate

I like this, but.. .. how could I put the labels to know +- over where value I are moving? for examples, between 0 and 8. ...
-1
votes
1answer
34 views

Are there a function to choose the greatest value in a discrete function? [closed]

Supose a discrete function show 1st, 2nd,...6th value are h = {5, 4, 2, 8, 9, 1} And I want to find the maximun in the subset of indexes 1,3,5,6 (what are ...

15 30 50 per page