All Questions

Filter by
Sorted by
Tagged with
2
votes
1answer
222 views

Copy TraditionalForm output to TraditionalForm input while keeping formatting

When I want to copy a scientific notated number from a TraditionalForm output to an input it formats it in a weird way: Another thing I want to do is only copy a few number of decimals, and remove ...
13
votes
2answers
425 views

Internal “Periodical” functions in version 7

In version 7 there exist these Internal` context functions: ?Internal`*Periodical* AddPeriodical   ...
1
vote
1answer
722 views

NDSolve does not give me the expected solution

I have an assignment where I need to compute chemical reactions by solving ODEs. I use NDSolve to do this. However, for one problem it does not give me the ...
6
votes
2answers
14k views

How to plot two sets of data on one ListLinePlot

I have two sets of x,y coordinates, and want to plot them both on the same graph. With one set, List1 $= \{ \{ x_1, y_1 \}, \{ x_2, y_2 \},\{ x_3, y_3 \}, \cdots \}$ I can use ...
6
votes
1answer
3k views

Unable to convert $\TeX$ input into mathematica

The input ToExpression["\\sqrt{x y}", TeXForm] gives me the $Failed output. Maybe my very old computer is the problem, but ...
22
votes
4answers
957 views

Making a symbol's new definitions be tried before all previously defined ones

Is there any way to "close" a package (or a symbol, or a context) in that if a user of the package adds definitions to the symbol they will be tried before the package defined ones, just like what ...
40
votes
5answers
4k views

Aborting evaluation when the memory exceeds a certain limit

Sometimes when generating a lot of data the memory usage shoots beyond its physical realm and my laptop freezes. There is no way to stop Mathematica when this happens. Task manager (or its equivalent ...
18
votes
1answer
275 views

hat not big enough

I like to use Mathematica text cells for creating draft technical documents. When entering equations in a text cell, the ^ (hat accent) does not dynamically adjust its size to fit. It looks good if ...
20
votes
2answers
5k views

Arrows on axes in Plot3D

I use the following code to draw Arrows on Axes in 2D graphics: ...
20
votes
3answers
4k views

Fitting fractional complex data with NonlinearModelfit

I've difficulites with the NonlinearModelFit function. In principle Mathematica should be able to deal with complex data. E.g. if I define the following table <...
14
votes
2answers
5k views

Difficulties with Importing PDFs in Mathematica

I am trying to import a group of PDFs that I have downloaded (it is in the realm of 1,000+). They are a group of doctoral dissertations that I'm trying to automatically extract bibliographic ...
22
votes
4answers
2k views

How to match a pattern with a pattern?

UPDATED This question is about: "What is the pattern to match a pattern-definition, exactly as it is written?" My original question is now split according to Mr.Wizards insightful answer below. This ...
9
votes
2answers
749 views

Producing a bar chart with height and color determined by two distinct lists

I am trying to visualize a list of positive integers using a bar chart. In general, integers in that list may appear more than once. For example, I may have ...
23
votes
1answer
2k views

Using ImageCapture to access a USB webcam in linux

Is it possible to access a USB webcam through Mathmatica on Linux? When I run ImageCapture[] I get the following output ...
4
votes
1answer
829 views

NDSolve Problem

I am trying to solve a chemical equilibrium ODE with NDSolve where one function is the argument to another. I.E. My equations look like: ...
24
votes
4answers
1k views

How to partition a disk into individually spaced bricks?

What I want to do is in any way produce a picture that looks like this Given a set of words, how can I partition a disk into bricks for these words, such that it looks good? Here is my sucky ...
3
votes
2answers
2k views

Plot Indefinite integral

I'm having a hard time to find a solution to a numerical limitation on mathematica: ...
4
votes
1answer
426 views

Explanation on why Compile statement works only if input and output sizes work

I found the following code: Compile[{{m, _Real, 2}}, Fourier[m]][Table[N[i - j], {i, 4}, {j, 4}]] which doesn't work correctly. But the following was posted as a ...
3
votes
1answer
263 views

Undocumented Dynamic Function question

In the code below the value displayed next to the slider may be correct, and should be the result of The value of x for cyL and ...
4
votes
2answers
344 views

Efficiently evaluating a held expression directly from a list

I am able to evaluate a held expression that I have put on a list by: ReleaseHold[expressionList[[1]]] and ...
5
votes
2answers
933 views

Wavelet Packet Transform in Mathematica 7 and 8

For finding location of spikes in a time series I used to transform the data into wavelet space using DiscreteWaveletPacketTransform [ data, filter, 0] and then ...
16
votes
2answers
933 views

Listing subgraphs of G isomorphic to SubG

If I have an undirected graph G, how could I write a function in Mathematica to obtain a list of subgraphs of G that are isomorphic to some other undirected graph SubG? I'd like to learn how to ...
14
votes
2answers
832 views

How to REALLY Hold arguments and capture FullForm?

I'm trying to write an expression deconstructor or FullForm-capturer; might even call it a parser, maybe, but that might be too glorious a word. I got some great ...
4
votes
1answer
522 views

Deleting parts of a large list

At present I am running an analysis on economic data. Within the data I was able to identify countries which went through recession. I then calculated for example the average decline rate of GDP ...
13
votes
1answer
276 views

Effects of single-point and multi-point calls of Point on plot range

Several Graphics primitives are listable. For instance, Point accepts lists of coordinates so that multiple calls to Point are ...
19
votes
1answer
510 views

Are there advantages to using additional arguments of common functions rather than alternative ways of calculating with lists?

(Apologies for the long question title.) One of the interesting, if sometimes confusing, things about Mathematica is that there is always more than one way to do things. Even intermediate users can ...
21
votes
2answers
2k views

Why does Mathematica give the wrong answer when integrating?

Bug introduced in 8.0 or earlier and fixed in 9.0.0 I integrate Integrate[Exp[I Cos[b - c]] Cos[b], {b, 0, 2 Pi}] Mathematica gives: ...
3
votes
1answer
419 views

Incorporating an additional graphics element when using Animate and ParametricPlot3D

I'm trying to animate some curves that wrap around a cylinder. OK so far: ...
23
votes
2answers
1k views

Ordering problem

Let's look at the following example. Ordering[{0, 20 Sqrt[5], 40 Sqrt[5], 20 Sqrt[5], 20 Sqrt[10]} // N] gives the right answer ...
9
votes
1answer
759 views

Gröbner basis on a particular set of equations

This question is very similar in gist to equation solving with GroebnerBasis, but hopefully when I say that I make the system a little larger I mean little. I have ...
25
votes
3answers
4k views

Cycles of length N in a graph

If I have an undirected graph represented with an adjacency matrix, how can I find all the subgraphs which are a cycle of length N? I don't really know the math nor the programming language well, so ...
32
votes
3answers
3k views

Generating graphs interactively (GUI)

I want to create graphs interactively using a GUI. I thought of using a ClickPane[] environment. The code I have (in part borrowed from the Documentation) works ...
8
votes
2answers
2k views

Filling global arrays in parallel calculations

I want to parallelize heavy computations which has to be done many times, the result should be arrays of data. Each calculation does not depend on others (but uses the same variables though). The ...
33
votes
4answers
3k views

Clustering of space-time data

Below is an example of a gaze sequence I recorded during a 3 seconds display. That is, where the eye was at every millisecond. While we should have 3000 points, we are missing some due to blinking. ...
-18
votes
4answers
740 views

Going Beyond Pseudorandom Numbers

I cooked up this simple bit of code in hopes to exceed pseudorandom number generation maybe touch the face of true randomization: ...
17
votes
3answers
398 views

Is there a way to require confirmation for execution of certain cells?

Often I have Notebooks where I generate several images and export them into files. Now when I want to change one image, I'd like to just re-evaluate the complete notebook, however I generally do not ...
15
votes
3answers
2k views

How to implement a regular grammar?

What is the most simple, elegant way of implementing a rewrite-system defined as: $$ \begin{aligned} \Sigma &= \{a_1, a_2, a_3, ...\} \\ N &= \{A_1, A_2, A_3, ...\} \\ \{\alpha_1 , \...
5
votes
1answer
432 views

How to match two sets of data over 1 or more identifier, of unequal length?

Brief Question about how to best match lists with Criteria from Identifiers (thus for me: translate SQL to Mathematica ;) ). If I have two sets: ...
9
votes
7answers
526 views

How to efficiently Append a result of an operation on each element of a list to itself

I'm looking for the best function to apply the product of the last two elements of sublist elements to each element: Example: ...
8
votes
2answers
947 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 ...
22
votes
2answers
1k views

How to inject an evaluated expression into a held expression? [duplicate]

I know that there are methods to structurally manipulate held expressions (discussed e.g. here), but I failed to apply those for this particular problem: ...
10
votes
1answer
504 views

How to copy hyperlink addresses using the keyboard

I would like to copy the address of a hyperlink in Mathematica using the keyboard. I found code for copying hyperlink addresses in ContextMenus.tr: ...
5
votes
1answer
521 views

MUnit creating a hierarchy of TestSuites

I would like to create a hierarchy of TestSuites. However it appears that it is not possible to call a TestSuite from another <...
6
votes
1answer
635 views

Obtaining a thin/compact SVD

I'm using SingularValueDecomposition for a least-squares regression, the instruction that works fine for what I need is ...
5
votes
2answers
601 views

Equation solving with GroebnerBasis

I have a system of quadratic equations defined below ...
14
votes
6answers
4k views

How do you skip missing data values in a data file?

In scanning through a simple imported file of weather station data, some dates have missing data. What is a test to use to check whether a datum is valid? I tried ...
6
votes
1answer
1k views

ErrorBars with BarChart, ChartLabels are not working?

In the Add Error Bars to Charts and Plots How To in the Mathematica documentation a function ErrorBar is given: ...
16
votes
5answers
6k views

Labeling a bar chart, changing how rotated labels are centered

I'm trying to label a bar chart with rotated labels see this simple example: ...
25
votes
5answers
5k views

How to pass a symbol name to a function with any of the Hold attributes?

Given a function with the attribute HoldFirst, HoldAll or similar, and a variable, list, how ...
86
votes
5answers
10k views

What does the construct f[x_] := f[x] = … mean?

This question mentions "x := x = trickery". What does defining a function as f[x_] := f[x] = ... do and what is it good for?

15 30 50 per page