8
votes
4answers
2k views

Force function to make assumptions about its input variables in Mathematica

I'm trying to force a Mathematica function to make an assumption about its input variables. In my case, I'm trying to define a function to return the pdf of a Gaussian. But let's use a simple toy ...
10
votes
1answer
1k views

How to specify the InputField as a String in Manipulate

I'm putting together a Demonstration which utilizes a function which operates on a (manipulated) String, and I'd like the ...
4
votes
2answers
976 views

GridLines in LogPlot or LogLogPlot

Suppose I have a plot like LogLogPlot[2 x^5/3, {x,0.1,10}, GridLines->Automatic] How can I achieve to get "custom" gridlines to reduce the number of ...
14
votes
8answers
860 views

How to Map a subset of list elements to a function?

How would you, given a list {1, 2, 3, 4}, apply a function f to 1 and ...
30
votes
2answers
1k views

Aligning plot axes in a graphics object

I need to align the y-axes in the plots below. I think I'm going to have to do some rasterizing and searching for vertical lines, then vary x and ...
3
votes
1answer
494 views

Solving an ODE numerically

I really appreciate it if anyone helps me with this: How can I solve this ODE and plot the answer for $x$ on $[0.6,5]$: $$ \begin{align*} -2xy'[x] = y''[x]+ 47.21 (-.0025 x^6 & + ...
12
votes
3answers
354 views

What is an efficient way of selecting multiple colors via Manipulate?

Background: The following snippet is what I (intend to) use in a Manipulate form where up to 12 different colors can be selected: ...
7
votes
2answers
780 views

Integration with vector coefficients

I asked this same question in Mathematics, and it was suggested I might try here. I'm more comfortable with Maple, but if I can get Mathematica to do what I'm after, so much the better. Basically ...
6
votes
2answers
10k views

Plot legend inside a Show [duplicate]

Possible Duplicate: Using PlotLegends with Show messes up the graphics I have created a composite plot function: I want to add a legend to it, but ...
21
votes
2answers
2k views

Unsaved notebook is crashing: is there any way I can save the state of the MathKernel before I kill it?

So I'm in the middle of generating some plots and all of the sudden the frontend goes dead and I haven't saved my work. I'm using Mathematica 8 in MacOS X. The MathKernel process is still running and ...
14
votes
2answers
537 views

Are there advantages to using generalized Part extraction instead of specialized functions like First, Last?

There are many ways to extract different parts of lists in Mathematica. For example, the first part of a list v can be accessed either as ...
52
votes
4answers
17k views

Creating legends for plots with multiple lines?

So I have a graph with multiple lists, for e.g. data = {{1,2}, {3,4}, {3,5}, {2,3} . . .} If I then do ...
10
votes
8answers
2k views

Map and Apply a function on a nested list

I have a list like this: {{1,2}, {4,2}, {6,4} ... } I want to replace every second number with a function of that number. For e.g. ...
24
votes
4answers
4k views

Computing and plotting a spectrogram in Mathematica

How can I compute and plot the spectrogram of a signal/time series/data in Mathematica? I have a WAV file, sampled at 44100 samples/second and I want to generate a spectrogram of that data. Something ...
3
votes
3answers
317 views

Combining heads of lists so that you can create a nested list from two sublists

I have a list such as list = {1,4,3,4,6,3,1,2,3,4 ... } and a range, say, range = Range[20000]. I want to obtain the following ...
13
votes
5answers
848 views

How to thread a list

I have data in format data = {{a1, a2}, {b1, b2}, {c1, c2}, {d1, d2}} Tableform: I want to thread it to : ...
12
votes
4answers
4k views

Minimizing a function of many coordinates

I'm trying to obtain a series of points on the unit sphere with a somewhat homogeneous distribution, by minimizing a function depending on distances (I took $\exp(-d)$). My points are represented by ...
17
votes
2answers
1k views

FindFit returns Infinity::indet error when data contains {0,0}

Let's consider the following data: data = Table[{q, 2*q^2}, {q, 0, 2}]; and then, do a very simple fitting to this data: ...
12
votes
1answer
373 views

Function as an option to a function

I am new to mathematica ,so this question may seem a little naive. I know how to use the option as an argument to a function, we can define an option by using ...
4
votes
1answer
238 views
11
votes
3answers
3k views

Saving high-quality graphics through commands

Say I make and display a graph in a Mathematica notebook: graph = CompleteGraph[100] If I drag the corner of the graph to increase its size, and then save it to ...
9
votes
1answer
474 views

GeoDirection and GeoDistance Memory Leaks: How to Recover the Memory?

The functions GeoDirection and GeoDistance have memory leaks. To see this, run the example functions below and watch as the Physical Memory Available in the Windows Task Manager, Performance tab, ...
4
votes
1answer
291 views

How do I use the result of Solve in a function definition?

I'm trying to adapt the following piece to the part where PowerF is a function of amax. ...
27
votes
3answers
2k views

Histograms with pre-counted data

I've got some large data sets which have been counted but not binned already - essentially, a list of pairs of values (not bins) and counts.* (Or, equivalently, it's been binned into too-small bins.) ...
6
votes
1answer
404 views

Dialog crashes Mathematica

I have some dialog windows in a GUI of which one regularly crashes the kernel. I managed to focus on this particular piece of code, though I don't really know what causes the crash: ...
4
votes
2answers
2k views

ArcTan expressed as a radian fraction?

This type of answer is what I'm looking for: In[58]:= ArcTan @ 1 Out[58]= π/4 This is what mathematica gives me: ...
13
votes
4answers
1k views

Importing HDF5 with compound data

I am looking to Import HDF5 data with compound data. It appears, at least from what I read, that Mathematica 8.0.4 (and previous versions) does not support reading ...
48
votes
3answers
6k views

Understanding CDF

Update Since more and more issues are revealed as I venture deeper into the world of CDF, I decided to make this thread more general and hopefully more useful. I know posted my findings as an answer, ...
29
votes
2answers
2k views

Animating a Voronoi Diagram

edit: Excellent answers have been provided and I made an animation which is suitable for my use, however, all the examples rely on bitmap/rasterized data; is there a vector based approach? I would ...
5
votes
2answers
762 views

Expression evaluation inside of FindRoot inside a Compiled Function

I'm trying to get some performance increase out of my own implicit differential equation solver using Compile[]. The uncompiled function is of the following form: ...
10
votes
4answers
463 views

Extracting equations from Piecewise expressions

Say I have a PDF: PDF[LogNormalDistribution[1.75, 0.65], x] Calculating it, Mathematica gives me an expression that looks like this: I want to extract the ...
5
votes
2answers
450 views

How to set the return type of a compiled function? (Compile::noinfo warning)

I have simple function I would like to compile, but I get a warning and a call to MainEvaluate. I would like to avoid both. ...
9
votes
3answers
1k views

How to use local variables with indices in a Mathematica Block environment?

I have the following code: Subscript[f, i_][x_] := Block[{a}, Subscript[a, i] = 3 x; Subscript[a, 1] ] If I evaluate for example ...
23
votes
1answer
388 views

Usage displays properly only after second call

If I have a usage message containig two-dimensional stuff (subscripts or formulas) and I call the usage, then sometimes I get an improperly formatted output enclosed in "...". Linebreaks are gone, but ...
18
votes
5answers
1k views

Managing formatted usage messages in Wolfram Workbench

We have numerous packages (defined in .m files) that we maintain and develop in WolframWorkbench (2.0), and in those packages, we use the traditional method of ...
18
votes
1answer
201 views

Is UndirectedEdge[a,b] the same edge as UndirectedEdge[b,a]?

Is UndirectedEdge[a,b] the same edge as UndirectedEdge[b,a]? Then please consider this. ...
7
votes
3answers
322 views

Why can't D[] be used in place here? [duplicate]

Possible Duplicate: General::ivar is not a valid variable when plotting - what actually causes this and how to avoid it? Beginner question: Why can't I use ...
3
votes
1answer
364 views

Export long filename truncated

I am seeing a weird behavior on exporting at least one type of file (here, a QuickTime movie) to files with long names. If I do this: ...
7
votes
3answers
610 views

How to create a list of pre-defined functions?

I would like to create a list of Cauchy distribution pdf's, having different locations of their maxima, and being multiplied by different factors; then I'd like to calculate those functions' values ...
5
votes
2answers
583 views

Stationarity tests

I have the Time Series package and Mathematica 8. In the package, there is the function 'StationaryQ' to test the stationarity of a known model. Is there any function in Mathematica to test the ...
16
votes
4answers
2k views

Printing exported PDF graphics fails (version 8)

When I export even simple graphics, say, a DateListPlot to PDF under Windows, it refuses to print on any of the printers at work. Acrobat (Reader X) throws three ...
9
votes
1answer
166 views

Accept Infinity as an Integer argument

I have the following function, albeit contrived: Foo[x_Integer] := Module[{i}, i = 1; While[i <= x && i <= 10, i++]; i - 1 ]; I am ...
38
votes
2answers
1k views

My donut has holes in it!

More than one hole, I mean… I’m trying to export from Mathematica into the X3D format, with the longer term goal of generating 3D figures for PDF inclusion. But I'm stuck at the first step: ...
11
votes
1answer
435 views

Mathematica implementation of Earth Movers Distance?

Has anyone implemented in Mathematica the Earth Mover's Distance (EMD)? A concept dating back to Monge 1871, used to compare histograms and images, e.g., the CIEDE2000 Color Difference algorithm. ...
8
votes
2answers
280 views

Cases[data,Colon[key,_]] vs. Cases[data,key:_] toward XPath, XQuery

Exploring methods to index and search tree-structured key:value pairs via named-entity index (key paths) as opposed to Position-based indexing. Using Rule as ...
17
votes
2answers
466 views

Using several anonymous functions mixed together

This works: list // BarChart[#[[2]], ChartLabels -> DateString @@@ #[[1]], ChartStyle -> "Pastel"] & This doesn't: ...
17
votes
4answers
484 views

Getting lengths of sublists that sum to more than one

I have a long list of numbers, and I'm interested in finding the length of each sublist that totals to more than 1, so for the list ...
12
votes
1answer
283 views

Exporting and reimporting a list of lists changes the dimensions

Could anyone explain to me what in the world is going on here and please help me in reading in dummy.dat properly? ...
23
votes
3answers
8k views

Plotting Error Bars on a Log Scale

I have a plot with ErrorListPlot ...

15 30 50 per page