1
vote
0answers
4 views

Geographic background containing both outlines and contours: how?

I would like to create a map which will show lakes and rivers together with elevation contours and contour labels. What is the simplest way to do this with ...
0
votes
0answers
7 views

how to write TableForm expression into file?

Now I have a list stored in data as follows data = {{"Ca", 1, 1, 1}, {"Ca", 2, 2, 2}, {"Ca", 3, 3, 3}} the ...
0
votes
0answers
14 views

Finding Roots of Non-linear Systems: Rescaling polynomials

I'm trying to get all isolated finite equilibria of a moderate multi-dimensional non-linear system of equations. Particularly I have 9 independent variables and third order at most. It turns out that, ...
1
vote
0answers
15 views

How to avoid joining MathieuCharacteristicA in a plot?

In the documentation As a function of the first argument, MathieuCharacteristicA is a piecewise continuous function So how to avoid joining different pieces of the function? For example, ...
0
votes
0answers
14 views

Solve and NSolve for large models

I'm a Mathematica rookie running version 7.0 for Mac OS X x86 (64-bit) (February 19, 2009) on a 2010 MacBook Pro. (I'm also a stackexchange "newbie" who originally posted this on stackoverflow, thus ...
-1
votes
0answers
12 views

EvaluationMonitor is evaluating up to 3232 steps

I have the following objective function which I want to minimize using simulated annealing. fourVertIsoHamilt[x11_, x12_, x13_, x14_, x21_, x22_, x23_, x24_, x31_, x32_, x33_, x34_, x41_, x42_, ...
0
votes
0answers
30 views

Ordering oscillators with negative powers: Infinite loops

I have been working with ordering of oscillators for example $[a,a^\dagger]=1$ and I have a fairly stable code. I have needed to use inverse oscillators for example expressions like $a^m ...
0
votes
2answers
28 views

Changing the data indices for a large dataset plotted with ContourPlot

I have a large (square) dataset that I am plotting with ListContourPlot ... The data is 128x128 -- without coordinates for each point. I.e. - {{0,0,1,0,...,0},{0,2,1,1,...,1},...{3,1,1,1,...,2}} So ...
0
votes
0answers
17 views

Asymptotic expansion on 3 nonlinear ordinary differential equations

The 3 nonlinear differential equations are as follows \begin{equation} \epsilon \frac{dc}{dt}=\alpha I + \ c (-K_F - K_D-K_N s-K_P(1-q)), \nonumber \end{equation} \begin{equation} \frac{ds}{dt}= ...
3
votes
1answer
29 views

Sqrt disappeared when exporting plot to PDF in version 10

In version 10, if we plot with Sqrt in y-axis, and export to PDF, the square root disappears in the PDF file. ...
1
vote
1answer
20 views

NDSolve: EventAction list specification using Table fails

I have an NDSolve problem that needs a list of a large number of events that are generated programmatically. Here is a simple example that demonstrates the problem on Mathematica 7 and 8 (the versions ...
0
votes
0answers
31 views

Complex infinities in an Euler-Lagrange equation

I now wish to solve for $L(t)$ and $H(t)$ some ugly Lagrangian (in the code below) in configuration space, respectively the length and the height of a system. I tried running the code below, with the ...
2
votes
3answers
133 views

Create a list of random reals

How can I create a list of random pairs $(x,y)$ where $0<y<x<1$ and $x,y \in \mathbb{R}$ ? I can't seem to place that inequality restriction on the random numbers that are generated.
3
votes
1answer
42 views

One ChartLegend for multiple charts in Dataset?

Dataset's documentation shows how to leverage GroupBy operator at multiple levels titanic[GroupBy[Key["sex"]], GroupBy[Key["class"]], ratio, "survived"] Taking a ...
1
vote
1answer
26 views

Can I use what “headerlines” removes from a CSV as TableHeadings for the table I create from that File?

I am reading in some data from a CSV file that has a line which gives titles to each "column". Here is an example: ...
0
votes
1answer
32 views

Simplifying a symbolic product of rational powers

I'm trying to symbolically evaluate a lot of equations that can consist of up to 10 parameters. The form of these expressions is a product/quotient of rational powers of the mentioned parameters, ...
2
votes
1answer
41 views

How to read from /dev/random?

I am looking to read a few bytes from /dev/random on OS X and Linux. The simplest approach fails on both operating systems (see below). Why? What is a ...
7
votes
4answers
184 views

Possible bug in Dynamic

The code below crashes the Mathematica kernel in version 10 (not in V9) every time I run it on Windows and on Mac OS. I've sent it to WRI, but was told that they could not reproduce the crash. Does ...
0
votes
0answers
12 views

How do I turn my verbal argument into something formal in Real Analysis? [migrated]

So one of the exercises I am doing is to prove (or disprove) that 'Every compact set on a metric space is bounded'. Verbally, I can 'prove' this by simply stating: "If the every compact set on a ...
3
votes
3answers
75 views

How to transpose x and y axes on a LogPlot?

Consider the following simple LogPlot: LogPlot[Exp[x],{x,0,5}] Is there a nice way to switch the axes of a LogPlot? I'm aware that plotting the inverse ...
4
votes
2answers
91 views

Extrude 2D cross-section to 3D shape with shrinkfactor

I would like to create a 3D shape from extrusion and scaling of a 2D contour. The 2D contour that I have looks like this: and it consists of a bunch of points (here plotted with ...
0
votes
0answers
59 views

Security of the Wolfram Programming Cloud? [on hold]

We have a number of projects where we a contractually obligated to safeguard client data and intellectual property. Prior to using a tool or technology, we must provide documentation that shows how ...
3
votes
2answers
112 views

Spike train representation

I have a spike train. The data shows the time at which the neuron fired a spike. I want to plot them like this picture: Here is the data for one spike train which corresponds to the one of the ...
0
votes
0answers
27 views

NDSolve PDE, not enough boundary condition?

The PDE that I want to solve is: $$ \frac{\partial f}{\partial t} + \frac{1}{m} \left( p_x \frac{\partial f}{\partial x} + p_y \frac{\partial f}{\partial y} + p_z \frac{\partial f}{\partial z} \right) ...
2
votes
1answer
59 views

About Compile Function

I have a function that take p as a parameter, p is a 2X3X3 list, ( a 2X3X3 list can like { {{2,3},{1,2.},{1,1.}}, {{2,3.},{1,2},{1,1}}, {{2,3},{1,2},{1,1}} } ) the function just as: ...
5
votes
2answers
139 views

Line style thickness differences between Mathematica 9 and 10

I execute the same code in Mathematica 9 and MAthematica 10, and have this different results. ...
13
votes
2answers
743 views

Best practice of passing a large number of parameters to functions

I have a number of functions which all take a large number of parameters. I am wondering which is the best practice of passing these parameters to those functions. I could of course simply specify the ...
0
votes
1answer
36 views

How to use an output of a Solve function in further calculations? [on hold]

Following is the polynomial equation that gives me a single real root: ...
0
votes
0answers
40 views

Conditions under which a given function is less than zero [on hold]

I have a function say F(a,b,c,d,e) which I know can be positive or negative, depending on the values of the variables. Assume F(a,b,c,d,e) where variable "e" is the solution of G(a,b,e)=0 Is there ...
1
vote
4answers
79 views

Replacing more than one element from a Sublist

The following expression allows me to extract the value of x and y: ...
3
votes
2answers
75 views

Lookup in Inverse Symbolic Calculator+ from Mathematica

There is a useful feature in WolframAlpha that allows to find a possible closed form for approximate numeric values. It can be used, for example, to guess the value of an integral that Mathematica ...
0
votes
0answers
19 views

Simplify expression by restricting variable to be integer [on hold]

I have an expression $$\sin [2 n \pi]$$ here $n$ is an integer. How can I let mathematica know $n$ is an integer, so the expression is simplified into $0$?
0
votes
0answers
85 views

why is mathematica 10 much larger than 9 in disk space? [on hold]

I found that mathematica 10 requires 8.8GB disk space while version 9 only asks for 5.5GB. So what are the major differences? What kind of new features gives rise to the increase?
0
votes
0answers
34 views

What is taking so long in this simplification?

I killed this after 48 hours, it did not seem to be getting anywhere. In the best of all possible worlds it would spit out n!. If I put the summation in a function it does compute factorials ...
0
votes
2answers
43 views

Suppressing reduction in fraction box size in multi-level fractions [duplicate]

Mathematica display complex fractions like this, the second x look smaller, I want it look like this, how can I get it in Mathematica?
4
votes
1answer
77 views

Agglomerate output to Graph

I'm using the HierarchicalClustering package to cluster some data. So let's say I have this: ...
0
votes
0answers
33 views
5
votes
1answer
70 views

Using J/Link with Wolfram Programming Cloud

Is it possible to use J/Link in a Wolfram Programming Cloud notebook? I need it to load and use 3rd-party .jars.
0
votes
0answers
47 views

Finding Symmetries of Points on a Sphere

Currently, I am working on a project where I would like to find symmetries of points plotted on a sphere. One example would be to rotate the sphere 180 degrees about the x-axis and the picture would ...
6
votes
3answers
104 views

AssociationMap to query Dataset across levels?

Is there a way to operate on Dataset across levels to apply a function f to a key -> value pair in an Association as follows: ...
1
vote
1answer
57 views

notebooks not opening in mathematica 10

I`m a guest here, and thought I could just ask you guys. ...
1
vote
1answer
44 views

Constraint in a 2D plot with Legend

I have the following plot: ...
1
vote
1answer
43 views

Numerically Integrating to find a Maximum using NDSolve

I am trying to numerically find an equilibrium (maximum) of a function using its differential. The following is a simplified version. ...
1
vote
1answer
46 views

Some question on “Reduce”

Is this my mistake? I am trying to solve ...
0
votes
0answers
28 views

Set min and max ranges for axes in ParametricPlot

I'm having trouble with this one plot I'm trying to make. I'm using NDSolve on a system of differential equations and when I plot it with ParametricPlot, the scales or lengths of the graphs axes come ...
0
votes
0answers
35 views

Is it possible to build/simulate/extract data from a System Modeler model completely inside a notebook using the MathModelica language syntax?

See examples in: http://www.mathematica-journal.com/issue/v10i1/contents/MathModelicaPaper/MathModelicaPaper_2.html It seems to be ruled out by the statement (Chapter 2 intro): "The subset of the ...
0
votes
0answers
41 views

Approximate a function of four variables with a rational polynomial

I have a function that consists of four variables. Currently, I want to view it as function of one variable over the interval (0, 1) with the other three variables as parameters. I will plug values ...
0
votes
2answers
44 views

Defining a function from a list [on hold]

I have a list of 49 numbers, and I would like to define a function f such that f(n) is simply the nth number in the list. How can I do this?

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