7
votes
1answer
159 views

How to plot inequalities taking into account that points must be integers and not reals?

I have solved with Mathematica 9 the following integer inequalities using Reduce: ...
7
votes
1answer
608 views

Normal lines to surfaces or planes in a 3D plot

How do I make the normal line to a plane actually look perpendicular? ...
7
votes
2answers
553 views

How to change an expression to Fortran90 form?

I have a large expression produced by Mathematica. To use this expression in my Fortran program I need to change it to a Fortran90 form. I am not satisfied with the ...
7
votes
1answer
124 views

Restrict access to Lightweight Grid

When using the default configuration of the Lightweight Grid Manager, anyone connected to the same internal network where the grid severs are can launch kernels on the grid. What possibilities are ...
7
votes
3answers
462 views

How can I get a running sum for a list?

I've got following data I'm reading from a file: ...
7
votes
1answer
210 views

Getting R textual output into Mathematica

I use Mathematica with R because I am able to keep my code and output organized with the notebook interface. Although I can get R structures into Mathematica using REvaluate, I can't figure out how to ...
7
votes
1answer
332 views

Log-scale histogram bug

Not really a question, more a solution to what I call a bug in mathematica v8(.0.0.4). I already sent a bug report to Wolfram. Problem The documentation for the Histogram-function explains the ...
7
votes
3answers
363 views

Filter list based on date

What I would like to do is remove entries from a list of instrument data when it is in maintenance. The maintenance data I have is a series of dates which look like this; ...
7
votes
3answers
388 views

How do we solve N-Rooks variation using primes?

Using a $p_n $x $p_n$ matrix, how can we solve the N-Rooks problem to find a prime in every row and column? ...
7
votes
1answer
912 views
7
votes
1answer
195 views

Is it possible to specify a context-sensitive, “depth-agnostic” rewrite rule?

I'm using the term "depth-agnostic" in this post to describe structural patterns featuring a "target" sub-pattern that can occur "at any depth" relative to one or more "context" sub-patterns. As a ...
7
votes
3answers
438 views

Specifying string patterns in DeleteCases

It seems that DeleteCases is not compatible with string patterns, at least directly (see, for example, this question). Is this true? If so, why is this the case? ...
7
votes
3answers
444 views

Is there an easy way to put time ticks on a parametric plot?

I have a parametric plot showing a path of an object in x and y (position), where each is a function of t (time), on which I would like to put a time tick, every second let's say. This would be to ...
7
votes
2answers
190 views

Internal Representation of ?name and ??name

Code FullForm[Hold[?name]] Syntax::bktmcp: Expression "Hold[?name]]" has no closing "]". Syntax::sntxi: Incomplete expression; more input is needed . Question ...
7
votes
4answers
2k views

Checking if two trigonometric expressions are equal

Say I have two trigonometric expressions which are a bit complicated. Is there a quick way to check if they reduce to the same thing (that they are equal) using Mathematica? I was solving this: $y'' ...
7
votes
3answers
218 views

Safely nesting RuleDelayed

Say I have the following, straightforward-seeming functions: ...
7
votes
3answers
417 views

Image of input and output cells is not exported correctly

Wolfram Blog uses PNG images to display input and output cells in a notebook. For example, the following is an image from Samuel Chen's post: I should be able to produce a similar image by ...
7
votes
1answer
585 views

Simplify an expression containing NonCommutativeMultiply

How does mathematica evaluate the following expression to zero: ...
7
votes
4answers
241 views

Evaluating a function using arguments from a sliding window over a list [duplicate]

Possible Duplicate: How to Map a subset of list elements to a function? I want to evaluate a function using arguments from a sliding window over a list. As an example, lets use ...
7
votes
2answers
188 views

Graph does not accept Property Options

My question is concerned with the Graph functionality, which was newly implemented in Mathematica 8. I already used GraphPlot ...
7
votes
1answer
1k views

Import DCD (CHARMM/NAMD binary trajectory) file

How can one import the coordinates stored in a binary CHARMM/NAMD DCD file? This is the structure of the file: ...
7
votes
1answer
184 views

How do I re-direct FilePrint's output?

I recently wanted to use FilePrint to print the contents somewhere else but in the notebook I was using. However, the obvious-seeming solution doesn't work at all: ...
7
votes
1answer
303 views

Setting the DifferenceOrder Option

I've been playing around with Method in NDSolve[...] and can't quite seem to figure out how to force ...
7
votes
1answer
106 views

$InputFileName backwards compatibility

What would be a good replacement for $InputFileName (which has been added recently to Mathematica 8) to achieve backwards compatibility with let's say M6 and M7? I ...
7
votes
3answers
457 views

Composition of functions

I have a number of rotations computed by rot = RotationTransform[theta, point], and I would like to compose them to produce one function that is the composition of ...
7
votes
2answers
588 views

Working with large data, pass-by-reference, compiled functions

I think I know the answer to this, but after two days of Googling, this is my last effort before going down an unwanted path... I have a function that takes lots of large data as arguments as well as ...
7
votes
1answer
179 views

DiracDelta attributes

Is there any reason why DiracDelta isn't a NumericFunction but DiracComb is? I just ate a ...
7
votes
2answers
248 views

What's the purpose of the Unique function?

As the title says: What's the purpose of Unique? I understand that it generates some unique symbol, but when and for what is it to be used? Are there applications ...
6
votes
2answers
387 views

How to reverse the direction of the y axes

I have a similar question to this one. Unfortunately, the answers there didn't help me. I would like to plot a simple function with the normal Plot function. ...
6
votes
4answers
193 views

Counting adjacent elements in a Matrix?

To start, I have a situation where I have some matrix, for example $$ A=\left[ \begin{matrix} 4&2&2&3&3\\ 2&3&1&2&3\\ 3&0&4&0&4\\ ...
6
votes
5answers
226 views

Removing reverse versions of lists from a nested list [duplicate]

I need to remove the reverse versions of lists from list of lists. I.e.: {{1,2},{2,2},{2,1},{a,1,2},{2,1,a}} I need to reduce to ...
6
votes
2answers
206 views

Inaccurate plot

Could someone please tell me how I can increase the accuracy of this plot, please? Or is there some other reason the lines are breaking up? ...
6
votes
1answer
169 views

In version 9 PlotLegends, how can I remove the strange edges that appear around LegendMarkers?

I'm running Mathematica version 9. I am using ListPlot to plot two sets of data. For each data set, I am using different ...
6
votes
3answers
140 views

Using PatternTest and/or Condition to detect equal list lengths as well as list element formats

On searching Mathematica.SE for information about overloading functions, I came across several threads about PatternTest and ...
6
votes
2answers
140 views

Looking for feedback on this function

I'm not sure this is an appropriate question; if not, I'm sure someone will close it :) I've got the following function, listed below; its job is to accept a graph (function) presented either as a ...
6
votes
1answer
274 views

Importing Excel Spreadsheet containing Array Formulas

Has anyone had any success with importing an Excel Spreadsheet holding an array formula into Mathematica? The Syntax I'm using is ...
6
votes
1answer
465 views

How can I get better control over StreamPlot?

I'm having some difficulties with the command StreamPlot in Mathematica 7.0. Here's the basic plots I'm doing : ...
6
votes
2answers
261 views

How to display the support supp(f) of a piecewise function z = f(x,y)?

I'm wondering how to display the support $\mathrm{supp}(f)$ of a piecewise surface $z = f(x,y)$. As an example, let's consider the following piecewise function (and plot it): ...
6
votes
2answers
206 views

Why Interpolation makes ListPlot3D slow?

I'm trying to use ListPlot3D to plot some data, and I'm using the InterpolationOrder option to make the plot smoother. But the ...
6
votes
2answers
1k views

How do you put conditions on indices in a sum?

I'm relatively inexperienced with mathematica, so I apologize if this is a trivial question. I want to take a double sum over a function $f(i,j)$ of two indices, of the form $$ \sum_{i = ...
6
votes
1answer
186 views

undisputed FrontEndTokenExecute

Thanks to this great topic, I've found the FrontEndToken that I was looking for: "DeleteGeneratedCells" (well, it is also ...
6
votes
1answer
178 views

Does it make sense to ask for the color of a Graphics3D “voxel”?

Say I generate some Graphics3D object, e.g.: Graphics3D[{Red, Sphere[{0, 0, 0}, 1], Blue, Sphere[{1, 0, 0}, 1]}] Does it make sense to ask for the color of a ...
6
votes
1answer
136 views

Why is FindInstance failing when I relax a set of constraints?

I'm attempting to use FindInstance to generate coordinate sets for plausible triangles with edge length distance constraints. E.g.: ...
6
votes
1answer
141 views

Could a package be composed of references?

Could a package be composed of references (e.g. usage messages)? Do the code for an induvidual function implemented in a package has to be physically in that package file where it is referenced (i.e. ...
6
votes
1answer
309 views

Filling only when one curve is below the other

I want to fill the area between two curves only when curve-1 (Black) is below curve-2(Blue). So In this example, I don't want the middle portion shaded but just the left and right tails to be shaded. ...
6
votes
4answers
370 views

How do I display an expression with negative powers?

How do I display an expression with negative powers? Mathematica seems to always invert a term with a negative rational power. None of the following work: ...
6
votes
1answer
327 views

Mathematica vs Sigmaplot (Non LinearModelFit)

I asked a question in a previous post that was closed because "The title of the question is not correct and the issue here is too trivial to help anyone later". NonLinearModelFit It's possible ...
6
votes
1answer
532 views

Properly Force Mathematica to Simplify Log Expressions/Rules

I want to be able to expand $\log(x^n e^x) = n \log(x) +x$: FullSimplify[Log[x^n Exp[x]], x > 0 && Element[n, Integers] && n > 1] yields ...
6
votes
6answers
345 views

How can I merge two lists in a special way?

It's been over a year since I've used Mathematica, and I'm having a total brain fart on a home project. I'd like to take an existing list of lists, say, ...
6
votes
1answer
305 views

Export graphics in parallel

I run a heavy simulation, using NDSolve and the method of lines. This means that the result of NDSolve is a list of, say, ...

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