# All Questions

249 views

### Equating and solving equations that have been generated using table[]

I am in the process of trying to use Mathematica to find the coefficients of transmission and reflection for the wavefunction of a beam of particles tunnelling across any number of identical potential ...
367 views

### Performance of numerical optimization with triple integral [closed]

I'm trying to solve a numerical optimisation that looks something like this: ...
173 views

### How can I threshold for a minimum value with MatrixPlot?

Looking at the Options for MatrixPlot, there doesn't seem to be a mechanism for lowerbound threshold - i.e. ignoring values that ...
283 views

### How to fix Ticks in Gauges?

Ticks is an option for Gauges. I fail, however, to apply custom Ticks to Gauges. For instance, compare these two: ...
263 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 ...
204 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 ...
214 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 ...
831 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: ...
1k views

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

I'm curious what's inside the InterpolationFunction object? For example: ...
257 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 ...
64 views

### Compiled version of interpolation function slower non-compiled version [duplicate]

Consider this code: ...
107 views

### Random variation inside NMaximize

I am using NMaximize as following code. ...
485 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 ...
956 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 ...
1k 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 ...
104 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 ...
150 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 ...
643 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 ...
212 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 ...
169 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: ...
90 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 ...
404 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 ...
654 views

444 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 ...
307 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 ...
816 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 ...
304 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? ...
434 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 ...
554 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 ...
244 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 ...
1k views

I am trying to use Mark Caprio's LevelScheme package for customizing graphics, but I haven't been able to get Mathematica to load the package using Get or ...
394 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 ...
331 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 ...
68 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 ...
191 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. ...
164 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 ...
463 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 ...
300 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 ...
364 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 ...
86 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 ...
221 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 ...
324 views

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 ...
590 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 ...
145 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 ...
408 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 ...
I want to solve the equation Det[matrix] == 0 which came from the consistency of solutions of a set of 8 equations. This matrix has two constants λ and μ and two variables $P$ and $q$. I want to get ...