# All Questions

2k views

### How to generate a random tree?

Is it possible to generate a random tree without explicitly constructing a random adjacency matrix that satisfies tree properties? How about a random directed tree? Edit: incredible answer by ...
1k views

### Improving NDSolve speed for heavily stiff problems

Having looked around the intergoogles and Mathematica.SE, I thought I'd pose a question with a minimum working example. Here is the situation I am trying to improve: I am solving a 4th order non ...
166 views

### What BarChart Option controls Joined line thickness?

Is there a named option that controls the thickness of the line segments that appear in BarChart with options ...
214 views

### How to partition MatrixPlot graphics?

Is there an easy approach - hopefully built-in - to partitioning MatrixPlot graphics into rows or columns (or both) of graphics sharing the same underlying options? ...
278 views

### Plotting two functions with dependent input function

I have defined a function: myJ2[n_] := 1/n* Total[RandomVariate[NormalDistribution[0, 1], n]^2] This is basically an approximation to the gaussian integral. I ...
462 views

### Loop and do operations on Matrix, then graph the results

I'm trying to do some operations to a matrix in a loop, and then I want to graph the results. The results are pair of numbers. Can I store the results of each iteration on "something" and the use ...
231 views

### Scale plot display area (within the frame)

I have 2 data sets of equal length. I've done a LinearModelFit of them which gives me: ...
55 views

### Make PlotMarker explanation [duplicate]

Possible Duplicate: Creating legends for plots with multiple lines? I have a ListPlot of data points. To distinguish between datapoints coming from different sources, I give them different ...
681 views

### How to vary color of fill between listplots based on y-distance between them

I have two lists with the same x-values but different y-values. I have used ListPlot to plot and fill the space (line) between them; however, I would like the color ...
329 views

### Why do Arrowheads interfere with ImagePadding?

Bug still present in version 10 under Windows. In a recent posting, Belisarius solved a problem related to the display of arrows on the x and y axes by setting ...
150 views

### Skip one step of the loop if there is an NIntegrate::eincr message

Is there a possibility of skipping one step of a loop if in this step there appears an error like NIntegrate::eincr? After skipping, the loop should go to the next ...
725 views

### How could I add arrows to the axis of a figure?

It is easy for me to add arrows to the axes of the a figure by taking advantage of AxesStyle -> Arrowheads[] when the differences between the horizontal and ...
519 views

### Faster code for specific problem

Sorry, but I need the following code much faster and I'm running out of ideas. I do appreciate any help. I post two of my fastest ideas (tab and mat), although they are not really fast. Thanks in ...
349 views

### singularity in NDSolve and Table command [closed]

We are considering the following equations ...
265 views

### Package found with Needs, but not with ParallelNeeds

I want to use a self-written package in a parallel computation. However while Needs["mypackage`"] works without problems, ...
3k views

### Integral equation numerical solution with NDSolve

I'm trying to solve something like: f[x] == Integrate[f[x]*g[x]] where g[x] is known and ...
301 views

### How to change the values dynamically in a grid

I am trying to write a function which creates a Grid which has no value in the starting and when some value is passed to it, it should show that value in that ...
1k views

### NonlinearModelFit::cvmit: Failed to converge to the requested accuracy or precision within 100 iterations

I have got a problem in my program with NonlinearModelFit: ...
424 views

### Total Variation Distance of probability matrix

How can I calculate the Total Variation Distance of a transition Matrix? is there any built in function? I've searched all documentation and haven;t found anything. ** More information: Let me try ...
2k views

### Spherical density plot of data set

I have a somewhat large number of 3-dimensional unit vectors ( ~ 100 000 unit vectors), and I am trying to visualize their distribution. First thing I tried was ...
530 views

### Linear Solve with Modular Arithmetic

I am interested in using LinearSolve[m,b] which will find a solution to the equation $m.x=b$, where I am in mod 2 arithmetic. Is there any way to perform this ...
745 views

### What are some advanced uses for Block?

I read the answer to this question and this one. According to those, Block is safer (if something aborts, it restores the values) and faster (perhaps something to ...
244 views

### LetL and Module efficiency

I was recently introduced to the LetL macro thanks to Leonid's answer to one of my prior questions. I was, needless to say, impressed by the simplicity of its ...
150 views

### How to silence all messages associated with a built-in symbol?

The post title's pretty much says it all... The reminder of this post just describes the little headway I made with this problem, FWIW. One would hope that ...
262 views

### Manipulate indexed Interpolating Functions

MWE I have some data indexed by gamma. For each gamma I want to find the intersection points of two lists and plot the lists ...
511 views

### Overlapping Red and Green ArrayPlots to show yellow intersections

Let's say I have two ArrayPlot[]s. One is in redscale and the other is in greenscale, such that the lowest value is white and the highest value is pure red or ...
701 views

### How to get 2D graphics into 3D without background?

Consider the following code: ...
368 views

### How can I export aligned equations to $\LaTeX$?

Using Palettes -> Writing Assistant -> Math Cells, you can enter aligned equations such as: ...
238 views

### Transform x-scale of data for e.g. MatrixPlot

I have to transform in a nonlinear way the x-scale of some data for a MatrixPlot (or ReliefImage or ...
148 views

### Confusing ReplaceRepeated & Hold

I've been bootstrapping myself to the very alien world of Mathematica and there came my first WTF moment: ...
6k views

### Custom arrow shaft

Inspired by Sjoerd C. de Vries' nice answer to this question, and the desire to pimp a Graph I did with Mathematica recently I would like to know if there are ways to customize the arrow's shaft ...
189 views

### Numerical comparisons of matrices

I have a matrix which should be equal to a null matrix. However due to the numerical precision, a brutal equality test with a matrix initialized with zeros does not work. How should I perform the ...
678 views

### Help to solve Simultaneous Equations

I think this should be easy to numerically solve in Mathematica, but for some reason I'm not finding the correct way to do it. I basically want to solve these simyltaneous equiations: ...
102 views

### NSum generates a warning message when getting the sum of a list

I know what I'm doing can be done with Total: a = Range@3; Total@a And if I simply choose ...
686 views

### stationary distribution of a transition matrix

How can I solve the stationary distribution of a finite Markov Chain? In other words, how can I estimate the eigenvectors of a transition matrix?
412 views

### How do I make my discrete plot thicker?

I am making a discrete plot and a regular function plot together. But my curve is so thick that for color-blind people, it's pretty much impossible to see the black dots of my discrete plot: ...
93 views

### Good Introduction / Tutorial to Mathematica **Books** [duplicate]

Possible Duplicate: Where can I find examples of good Mathematica programming practice? I'm a high school senior and am using Mathematica for a research project. However, I find it a bit ...
107 views

### How to give ClusteringComponents initial values?

I came across a variant of k-means that adds a algorithm to select good starting values called k-means++. ...
2k views

### Vectorizing an image like “Trace Bitmap” in Inkscape

Lately, we had a nice question about artistic image vectorization which got very nice answers. As Szabolcs pointed out himself Since "true" vectorization performed by various specialized software ...
503 views

### Simulating Stochastic Processes the MMA way

This question is really a specific problem and a methodological one concerning MMA best practices. I want to simulate a system of stochastic processes. If this were a geometric Brownian motion or ...
196 views

### Getting the 557th element of a table

Make a table with elements $\sin(\sqrt{8 n}/4) + r\,$for $n$ from $1$ to $1000$, where $r$ is a random real number between $-0.1$ and $0.1$ that is different for each value of $n$. Also make a ...
853 views

### Using J/Link to decode Google Maps Polyline strings

I would like to use this java code inside Mathematica using J/Link. It converts Google Maps API Encoded Polylines to a list of points. I tried the Mathematica tutorial but got lost. There is the Java ...
450 views

### Proper Filling of Self-Intersecting Polygon

I have a spiral pattern that I would like to fill, which self-intersects. My desired behavior is to have filling between neighboring lines only, and to represent this figure as a single polygon. The ...
427 views

### How draw dynamic empty rectangle over a bitmap?

I am trying to make a cookie cutter that will extract a small square from a much larger bitmap with a click of the mouse. The LocatorPane appears to be a useful way ...
236 views

### Saving graphics object in order to manipulate it later?

I've generated a bunch of graphics using ContourPlot wich, given the nature of my problem, take a long time to create, and I was wondering if there is a way to save ...
329 views

### BUGS-type calculations in Mathematica

Recently I have been teaching myself how to Bayesian calculations with the BUGS language (JAGS, in particular). However, I find myself wondering how one might use Mathematica to do similar ...
426 views

### Split string into sub-strings of length n [duplicate]

Possible Duplicate: Partition string into chunks How can I split a string into sub strings of length n? For example I have a string "ABCDEabcde1234" ...
505 views

### Superscript prime symbol

x\[Prime] looks like $x_'$, ugly right? Is there a way to make a symbol with prime to look like $x'$? That's what I'm trying right now: ...