8
votes
2answers
148 views

Which function definition is used to evaluate an expression that matches the lefthand side of more than one definition?

In a case like this: f[a_] := a; f[{a_, b_}] := a; I'm wondering whether I should expect f[{2, 3}] to return ...
8
votes
3answers
1k views

How to extract expression from ConditionalExpression

p1 := y /. {First[Solve[x^2 + y^2 + x == 1, y, Reals]]} ...
8
votes
1answer
232 views

How do I indent C code generated by SymbolicC?

I'm continuing to experiment with the SymbolicC` package, and it's crucial to be able to inspect the generated code in order to do, well, anything useful with it. ...
8
votes
2answers
1k views

Viewing Mathematica Demonstrations Project Code

I hope I am going insane and the I'm not seeing the snake about to bite me... How does one view the code in the demonstration projects that one can download from wolfram.com? It seems like all of ...
8
votes
4answers
267 views
8
votes
3answers
255 views

Applying a transformation rule on an Image

I haven't been able to figure out why the following doesn't work: ...
8
votes
2answers
956 views

Find the parameter values satisfying conditions for all roots of an equation

Hi I'm very new at Mathematica. My real problems concerns a much more difficult equation with many parameters, but I want to check that the method is good, so I made up a test equation. My test ...
8
votes
2answers
776 views

Why is Mathematica's expansion of expressions with square roots so slow?

Mathematica expansion of expressions with symbols isn't slow, but with square roots it is very slow. In Maple or Mupad both are fast: with square roots they both take less than a second. Here is an ...
8
votes
1answer
238 views

How to automate x[i]→x_{i}?

I have several Mathematica expressions in which subscripts are expressed with square brackets. E.g. x[12] is meant to represent x12, etc. If I evaluate ...
8
votes
2answers
770 views

Mathematica: Retrieving PlotRange from Histogram

I know that one can retrieve PlotRange of a plot by using AbsoluteOptions[plot,PlotRange] but that won't work on Histogram. Here an example: ...
8
votes
1answer
1k views

How to position legends exactly where I want them?

I just noticed another plot legend question today and while user solutions to this, in particular code by @Jens, are IMO better than the built in solutions, exact positioning often still requires some ...
8
votes
1answer
389 views

Making cells group

After reading rcollyer's post I'm still not able to understand how grouping rules work. Here is a problem I'm facing. What I want is to create a new title, section and subsection styles. I want the ...
8
votes
1answer
716 views

Exporting plots with Cyrillic text elements to pdf

I'm trying to export a plot with some added notes which happen to be in Russian. Using Mathematica 8.04 and WinXP I evaluate ...
8
votes
1answer
771 views

Hankel Transform integrals won't work in Mathematica

I'm trying to do this integral, which is shown on the Wikipedia page on the Hankel transformation: $$\int_0^{2\pi}\mathrm d\varphi\;e^{\mathrm im\varphi}e^{\mathrm ikr\cos(\varphi)}$$ The answer is ...
8
votes
2answers
254 views

How to generate Intervals from a given list?

If I have a list list={3,7,4,5,1} how to get the List of Intervals /Ranges result = {{1,3},{3,4},{4,5},{5,7}}
7
votes
3answers
202 views

Merging lists of pairs [duplicate]

I want to add several fluorescence spectra. They are lists of the format ...
7
votes
1answer
95 views

How to plot functions with large slope on a compact domain?

The Mathematica command Plot[(1 - r^2)^(1/32), {r, -1, 1}] does not plot the function near the boundary points. That is, the graph does not attain 0 at r = +-1. ...
7
votes
1answer
106 views

TransformedRegion, RegionPlot broken in 10.0.2.0?

After having had trouble applying TranslationTransform to a simple region like so ...
7
votes
2answers
203 views

Given the OneIdentity attribute why is GCD[a] evaluated to GCD[a]?

GCD has attribute OneIdentity so I expected GCD[a] being evaluated to a?
7
votes
1answer
337 views

How to code around known MMa special-case failures?

Fourier Analysis and Signal Processing often require these integrals on functions f[x] that won't be known in advance. ...
7
votes
4answers
132 views

Unexpected behavior using FromDigits to reconstruct polynomial

I have an issue with the reconstruction of a polynomial using FromDigits. The documentation of the function CoefficientList says: Fold the operation for multivariate polynomials: ...
7
votes
1answer
224 views

Understanding Dirichlet regularization in Sum

I've tried to calculate few classic sums using Dirichlet regularization: ...
7
votes
1answer
87 views

How to assign up-values for `Derivative`?

I have defined several custom analytic functions. Here is the simplest example: ln[x_, a_?NumericQ] := Piecewise[{{Log[x], Re[a] > 0}, {-Log[1/x], True}}] ...
7
votes
2answers
210 views

Behaviour of out (%%…%) with comments

Can please someone explain to me the diffrent behavior of this code (6 - 3); (5 - 3); (4 - 3); {%%%, %%, %} Out= {3, 2, 1} and this one ...
7
votes
1answer
216 views

User-defined template; removing repeated text (v 9.0.1)

In Mathematica 9.0.1, I want to write a user-defined template for a function that I wrote: myfunc ...
7
votes
1answer
538 views
7
votes
1answer
1k 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 : ...
7
votes
3answers
283 views

How can text-specific antialiasing be disabled in Rasterize?

While tinkering with the code in the Falling Matrix question, I was hoping to improve the rendering speed by making the rasterizations of the text grayscale. I changed the base color of the text to ...
7
votes
1answer
1k 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
4answers
249 views

Button's command is not evaluated in iteration

I wish I didn't feel like a newbie after several months, but... If I enter the following: Table[ Button[ "Number: " <> ToString @ i, Print @ i], {i, 1, 5}] ...
7
votes
4answers
482 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
2answers
194 views

Why aren't the locators independently enabled/disabled?

I am wondering why the Enabled setting for the first locator (point1) overrides the Enabled setting for the second locator ...
7
votes
1answer
343 views

Color ramp banding in PDFKit when exporting Raster image Inset to PDF

Here I produce a Raster image with large uniformly colored rectangles and put it in an Inset: ...
7
votes
1answer
401 views

Combining and aligning “chart” type graphics with regular plots

Is there an easy (recommended) way to align regular plots (e.g. ListPlot or Plot) with chart type graphics (...
7
votes
6answers
1k views

Trying to prove that $x\sin(\frac{\pi}{x})\ge\pi \cos(\frac{\pi}{x})$ for $x\ge 1$

Consider the function f[x_] := x Sin[Pi/x] I want to prove that this function is increasing for $x\ge 1$. This can be done with the first derivative. We have to ...
7
votes
4answers
596 views

Conditional numerical integration boundaries

I have a multidimensional integration of the form: ...
7
votes
3answers
478 views

ListPlot InterpolationOrder->0 datapoint centered

it is possible to get a histogram style in ListPlot using InterpolationOrder->0 ...
6
votes
2answers
100 views

Possible memory leak when importing JSON

Bug introduced in 10.0 and persisting though 10.2.0 This problem that I would like to resolve is how to free memory used Import a file when the file is no longer in use. I have a project in which ...
6
votes
1answer
174 views

Is there a built-in function to do binary search?

Is there a built-in function to do binary search? Say, given a list (sorted) and a number, find the position which keeps the listed sorted when the number is inserted. I know that ...
6
votes
2answers
104 views

Sum considers RandomInteger[] as a constant

Perhaps this is expected behavior, but I was kind of surprised by the following: ...
6
votes
3answers
215 views

Drawing a graph with vertex avoiding edges? (Handling vertices that must be colinear?)

I'd like to draw something like the following graph: ...
6
votes
0answers
112 views

Fine tuning compiled code that computes dilogarithm function

As an exercise of writing a good Compile function, I want to do the simple task of coding a routine that outputs the real part of the dilogarithm function ...
6
votes
8answers
431 views

Merging lists and adding common elements [duplicate]

I have two 2D arrays where some of the x-values are identical, L={{1,1},{2,2},{3,3}}; J={{0,1},{2,2},{4,4}}; I want to add these lists in the following way ...
6
votes
2answers
263 views

Matrix exponential via Cayley-Hamilton Theorem

I'm attempting to calculate the exponential of a matrix via Cayley-Hamilton theorem. (Following the "concrete example" from http://en.wikipedia.org/wiki/Cayley%E2%80%93Hamilton_theorem) I am having ...
6
votes
3answers
952 views

Understanding Bilinear ImageResize

In trying to understand basic image transformations, I have attempted to code my own image resize function that uses bilinear interpolation. I checked my work against Mma's ...
6
votes
1answer
206 views

How can multiple null terminated strings be handled in a DLL-function result?

I am trying to connect a classic System Dynamics tool (Vensim DSS) with Mathematica using a DLL that is included in Vensim DSS. Reading though the instructions on how to define DLL functions on how to ...
6
votes
1answer
267 views

Generate regularly spaced points from the surface of simplexes

I need to generate regularly spaced samples (points) from the surface of unit simplexes with 2 or greater vertices or end points. I can generate random samples pretty straightforwardly: ...
6
votes
5answers
2k views

How to sum over a List

list = {11.5575, 11.397, 5.52734, 4.0878, 2.54815, 1.86652, 2.55028, 2.14952, 1.6242, 1.34117} I have a list of numbers. How do I make a function that creates a ...
6
votes
2answers
277 views

Update a function avoiding infinite recursion

I am quite new to Mathematica and not completely familiar with functional programming. I am currently working with a function (call it foo) and wish to change its behaviour, for example, by adding 1 ...
6
votes
5answers
3k views

Specifying the size of open circle PlotMarkers in ListPlot

I would like to use ListPlot to plot some points. I would like the PlotMarkers to be open circles. I can use ...

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