4
votes
3answers
187 views

How to fix Ticks in Gauges?

Ticks is an option for Gauges. I fail, however, to fix custom Ticks to Gauges. For instance, compare these two: ...
2
votes
2answers
161 views

Simplifying expression to evaluate limit as $y\rightarrow 0$

I often end up with a function that contains the term $1/(1 + x^2/y^2)$, and I need to evaluate this in the limit $y\rightarrow 0$. By hand, I can rewrite this as $y^2/(y^2 + x^2)$, but how can I tell ...
0
votes
2answers
123 views

Can I speed up the following plotting code?

I have the following Mathematica code. I do get the output graphs, but it takes like 12 seconds, on my computer. Longer still if I increase the value of n1. Are ...
2
votes
2answers
100 views

Error when compiling function containing InterpolationFunction

I'm trying to solve a coupled ODE system using NDSolve. The coupling can turn on and off in some regions, and when the coupling is off, the solution can be written ...
4
votes
2answers
315 views

Numerical Integration as Model for Nonlinear Fit

I'm trying to do a fit for parameters of a function within an integral but I'm getting errors when I try and run it. Essentially I want the following fit to work out: ...
21
votes
1answer
343 views

What's inside InterpolatingFunction[{{1., 4.}}, <>]?

I'm curious what's inside the InterpolationFunction object? For example: ...
5
votes
1answer
150 views

Error messages from compiling the Piecewise function

The following works Compile[{{x, _Real}}, Piecewise[{{{0., 0.}, x > 5.}}, {1., 1.}]] but if I enter the Piecewise[...] in ...
0
votes
0answers
53 views
0
votes
1answer
92 views

Random variation inside NMaximize

I am using NMaximize as following code. ...
7
votes
1answer
218 views

StreamPlot with interpolating functions

While working my way through the Wolfram Blog post on simulating fluid flow I started playing with StreamPlot because I preferred quick and ugly visualizations over ...
6
votes
1answer
255 views

Eigenvector corresponding to a specific eigenvalue already found earlier

just a quick question that is very simple but somewhat hard to explain. I am using 4 specific eigenvalues of a large 80x80 k-dependant matrix. I found the 4 eigenvalues of interest for various k and ...
0
votes
0answers
99 views

Strange ParallelMap behavior

Let the symbol V denote an element of some vector space and nV its norm. Let lin be a linear ...
25
votes
6answers
493 views

Creating cross-version compatible documentation with Workbench

Wolfram Workbench allows you to create documentation for your own packages that is similar to the build-in documentation center. Integrating this type of documentation with the documentation center is ...
0
votes
0answers
114 views

How to pass Jacobian to IDA via NDSolve

According to the IDA manual, when solving DAEs, there is an option to supply $J = df/dx + c*df/dx'$ (where $d$ is for partial derivatives) to the IDA module. How can I do the same via ...
2
votes
1answer
77 views

Possible to Solve a LocationEquivalenceTest?

I have 5 groups, each containing around 20 elements. These elements are all dependent on x. For example: Set1 = {1.5x + 1, 2x + 0.5, 1 x + 1, ...} etc. Now, I want ...
2
votes
0answers
97 views

Generalization of a rule to N arguments

I am trying to apply a series expansion on a function x[t1,t2,...tn], with an expansion parameter a. For ...
3
votes
2answers
227 views

Speed of convergence for NIntegrate

I'm trying to optimise numerically a function that entails computing the expected value of a truncated trivariate normal distribution and this is taking extremely long -I also get warned about ...
4
votes
1answer
108 views

Saving a source file adds (* ::Package:: *) to the first line

I am running Mathematica 9 on a linux machine and I've encountered the following behaviour that I am trying to understand. When I'm editing multiple source (.m) files using mathematica saving adds a ...
6
votes
1answer
152 views

Graph rendering not working as expected

I'm running the older Mathematica v6 which seems to go through the edges of graphs twice. Is this a bug? Is it fixed on the latest version? Please just try this command: ...
1
vote
0answers
86 views

Using Dynamic to import the chronologically newest file in a directory [duplicate]

Imagine that I have a device continually and sequentially saving files to a specified directory on a Windows machine (such as [E:\ExampleDir]). Call this device a camera with some proprietary drivers ...
2
votes
1answer
132 views

How to change the start path of SystemDialogInput

It seems that every time the start directory of SystemDialogInput is always the same, is it possible to set the start directory to the last used directory? For ...
8
votes
1answer
317 views

Complex valued 2+1D nonlinear PDE using NDSolve

I am trying to follow the main ideas presented in this question, applying it to my own problem, which is a complex, time-dependent, nonlinear PDE: $$i \frac{\partial \psi}{\partial t} = \left[ ...
3
votes
1answer
153 views

Disable and Enable Hyperlinks Graphics

I have a Graphics element which I edit with Drawing Tools. I have determined a technique using NotebookWrite to add ...
1
vote
0answers
65 views

Efficiently generating 3D histograms for large sets 2D coordinates [duplicate]

I'm attempting to generate a 3D histogram for a large set of two-dimensional coordinates ($\approx 10^7$). the x- and y-components of each coordinate are rounded to the nearest integer, and these ...
6
votes
1answer
226 views

solve ODE with divergencies

The solutions of the second order differential equation $$\frac{1}{\eta}\frac{d}{d\eta}\left(\eta \frac{df}{d\eta}\right)+\left(1-\frac{s^2}{\eta^2}\right)f-f^3=0$$ is shown in Fig. 5.2 below, for ...
1
vote
2answers
154 views

Add keyboard shortcut to the DisplayFormula style

Is there a way to set up key bindings for the DisplayFormula and DisplayFormulaNumberedstyles? I am using Mathematica 9 on mac ...
0
votes
2answers
117 views

Unwrapping a list when invoking a function [duplicate]

The minimal working example of my problem is as follows: l = {1, 2, 3, 4} f[a_, b_, c_, d_] = a + b + c + d Now, I'd like to evaluate ...
1
vote
2answers
249 views

Integration and Parallel Computing in Mathematica

In mathematica, how would I use parallel computing (or paralleltable) to compute the integrals of $x^2$, $x$, $3x$ from $x=0$ to $10$ just like in the first answer of ...
4
votes
1answer
157 views

The limit of a product to infinity

What is the difficulty with this question to Mathematica? Is it just a problem with Mathematica v.8.0 or all versions are in trouble with it? Or is something wrong with my input? ...
2
votes
0answers
89 views

How can I set id attribute of elements when I export an SVG file?

Suppose I have a Mathematica graphic such as g = Graphics[{Disk[{-1, 0}, 1/2], Rectangle[]}] I would like to be able to export this graphic from Mathematica ...
6
votes
0answers
182 views

Remote Kernel - Error = MLECONNECT

Configuring a remote kernel with the Kernel Configuration Basic Options I manage to have a new kernel in the list of the kernel that I can open. However when I start the new kernel I get asked for the ...
3
votes
1answer
115 views

Check if an inequality holds among the solutions returned by Solve [duplicate]

Let's say I solve a system: Solve[{a == 3* c, b == 2 *a}, {a, b}] and then want to see if the values found for a and ...
4
votes
3answers
270 views

Can't load LevelScheme package

My problem is that I can not load the LevelScheme Package. I am using Mathematica 8. I downloaded and unzipped the folder from this website. I saved it in the ...
8
votes
3answers
208 views

PlotMarkers don't change colour for different lines

I have a set of data and several function operating on the same data, that I wish to plot together in a ListPlot. I need different ...
0
votes
1answer
180 views

Why the dollar signs when I Solve inside a Module [closed]

I would like the solutions of my equations to be local only, so I did a Solve inside a Module: Module[{a, b, c}, Solve[{a == 3* c, b == 2 *a}, {a, b}]] and the ...
1
vote
2answers
173 views

Clear labelling gray-scale plots

I am plotting a number of functions (at least 4 in one plot) with a legend. Needless to say, it is important that it is clear from the legend which line belongs to which function. I tried to play ...
2
votes
0answers
57 views

Are FEM methods integrated in NDSolve yet? [duplicate]

About a year ago there was a discussion on these forums as to whether FEM methods have already been integrated into NDSolve in Mathematica. The answer back then was ...
0
votes
0answers
120 views

My algorithm produces too many permutations

Imagine the following problem. A population of size $n$ consists of $i$ men and $n-i$ women. The population goes to the casino. Call $g_m$ ,$g_w$ the amount of money won by men and women respectively. ...
3
votes
1answer
114 views

Mouse click on BarChart elements

What I would like to do is explore a data set by clicking on elements in a BarChart. I have some existing code which uses a manipulate which I was hoping to modify. ...
0
votes
1answer
111 views

FindMinimum gives wrong solutions inside a loop

I have a density function $\rho(r,z)$ and I want to calculate the minimum distance $d_{min} = \sqrt{r^2 + z^2}$ from the center (0,0) in which $\rho$ becomes negative. The easiest way is to find where ...
4
votes
1answer
203 views

Erfi[z] expansion in Mathematica: is this a bug?

Looking at the expansion: Series[Erfi[x], {x, Infinity, 1}] I obtain -I+E^x^2 (1/(Sqrt[\[Pi]] x)+O[1/x]^2) (note the ...
1
vote
1answer
104 views

Lossless TIFF or PNG export

I'd like to export an output from MatrixPlot[], however, the output file size seems to depend on my specification of the ImageSize -> {..., ...}. How might I export a TIFF with all of the data in the ...
3
votes
0answers
198 views

Use of RegionFunction with Graphics3D?

I'd like to plot in 3D a long list of polygons created with TetGenConvexHull, but only in regions specified by a function. Is that possible? As I have it my ...
1
vote
1answer
77 views

Make the linked images show well?

Cell[TextData[{ "(16) ", ButtonBox["[images]", BaseStyle->"Hyperlink", ButtonData->{"http://i.stack.imgur.com/gHWby.png", None}]}], "Text"] After click ...
0
votes
2answers
118 views

Taking averages at certain intervals

I am trying to take averages of a large two dimensional array at certain intervals. For example, for the first row, I want to take K averages of 500 values. Here is what I am trying ...
6
votes
2answers
222 views

Add arrows over matrix

How can I plot this graph g1 = Table[x[i, j], {i, 5}, {j, 5}] // Grid; Rasterize@g1 I added these arrows by Ctrl+D's graphics tool. This way maybe hard ...
-2
votes
1answer
212 views

Define matrix in Mathematica [closed]

How are arrays allocated properly in Mathematica? Or how are the dimensions defined? For example, I can't do testarray[[1]] = 1 or Do[testarray[[i]] = i,{i,5}] Let's say I wanted to do the ...
10
votes
3answers
446 views

Multiple notebooks in Mathematica

While working with multiple files in Mathematica, is there a way to have the names of the files appear along with the minimized window of the file. I mean that sometimes I forget which file was places ...
2
votes
0answers
124 views

DownValues for Built-in Functions

N.B. I have bitten the bullet, and I am going through Leonid Shifrin's "Mathematica Programming: An Advanced Introduction." (Which needs no introduction in this forum) One question I have: could one ...
5
votes
4answers
250 views

Drawing normals to a curve

I want to draw a series of normals to a curve, where the curve has been parametrized by a single angle, i.e., the polar angle. The curve is actually sinusoidal perturbation of a circle of radius ...

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