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6
votes
4answers
1k views

SIGSEGV error with 3D Plots

I originally asked this question here but didn't get a satisfactory answer. I am using Mathematica 8.0.1.0 on Ubuntu 11.10. I created a 3D plot from an NDSolve ...
33
votes
5answers
2k views

Does every Symbol in Mathematica induce a monad?

From my question about types in Mathematica, I assume that every Symbol in Mathematica is a type if it appears as a Head of some ...
16
votes
1answer
2k views

Why does CUDAQ (from CUDALink) download data from Wolfram servers?

I understand why functions like ElementData or CountryData need to download up-to-date data when first launched. However, when ...
33
votes
4answers
3k views

What is a type in Wolfram Mathematica programming language?

"Everything is an expression" is a popular citation from many Mathematica guidebooks. So, what is type in Mathematica? How does it relate to common types from Haskell, for example? I did some ...
27
votes
6answers
14k views

Replacing composite variables by a single variable

To replace a single variable by another variable, one can simply use the the replace all (/.) operator (e.g., ...
21
votes
6answers
1k views

How do I generate the upper triangular indices from a list?

I have some list {1,2,3} How do I generate nested pairs such that I get {{1,2},{1,3},{2,3}} That is, I'd like a way to ...
40
votes
5answers
41k views

Plotting Complex Quantity Functions

Trying to plot with complex quantities seems not to work properly in what I want to accomplish. I would like to know if there is a general rule/way of plotting when you have complex counterparts in ...
14
votes
4answers
912 views

How to “ignore” an element of Map or MapIndexed

Say I have some function that I'm applying every element in a list to... if that element matches some criteria: ...
29
votes
8answers
2k views

Splitting words into specific fragments

I am looking into splitting words into a succession of chemical elements symbols, where possible. For example: Titanic = Ti Ta Ni C (titanium, tantalum, nickel, carbon) A word may or may not be ...
2
votes
1answer
2k views

Adding a circle to an already existing drawing

With reference to my earlier post: Adding a point to an already existing graphic I would like to add an outer circle to the whole drawing. This outer circle is a fixed one of ...
15
votes
3answers
2k views

Number format of axes in a plot

How can I have a conditional format of the values appearing in the axis of a plot ? I have in mind the number format options available in Excel for plots as described here http://peltiertech.com/...
19
votes
2answers
24k views

Formatting legend text font

I am using this code to plot a graph, and I am trying to make the font of the legend bigger. ...
4
votes
1answer
429 views

Using the same frame ticks for two different histograms

Consider the following: ...
50
votes
1answer
3k views

Google Map in Notebooks?

GoogleMaps are implemented as HTML and Javascript code which can be viewed by a web browser. Is it possible to load this map into the Mathematica notebook, which obviously means for example that <...
12
votes
1answer
325 views

Solve[ ] with Method -> Reduce gives a different result than Reduce[ ]

Why does Solve[Sqrt[x + Sqrt[x]] - Sqrt[x - Sqrt[x]] == m Sqrt[x/(x + Sqrt[x])], x, Reals, Method -> Reduce] give a different result than ...
22
votes
3answers
2k views

Reading from STDIN, or: how to pipe data into Mathematica

Today I tried using Mathematica's plotting capabilities to display the output of a C++ program. This made me wonder whether it is possible to somehow tell a Mathematica script to read from STDIN and ...
1
vote
0answers
294 views

Matrix multiplication involving MatrixForm [duplicate]

Possible Duplicate: Why does MatrixForm affect calculations? I am doing a matrix multiplication, but not getting the desired output. I am doing the matrix multiplication of $A^{-1}B$ from the ...
8
votes
1answer
251 views

How do I write a ValueQ function that only returns True if there exists an OwnValue?

Reading the comments in this answer has motivated me to request a full solution to part of this problem. What I'd like is an efficient solution that returns True ...
15
votes
2answers
593 views

Conditional Gathering of lists

Just need a little help with the GatherBy / SplitBy function(s). I have a list of random numbers here: ...
7
votes
2answers
7k views

Importing from Excel

I'm trying to import a matrix from Excel to Mathematica. My code is: Import["desktop/stproj.xls", "xls", data, 1] The output is some weird stuff about population ...
13
votes
2answers
371 views

Parallelization of distinct array write access from subkernels

I'm working on an implementation of a multivariate FFT, which is (or at least should be) highly parallelizable due to the row-column-algorithm. However, i can't figure out how to implement that. The ...
40
votes
4answers
1k views

Is there a convenient way to copy/paste text-interspersed SE code snippets into Mathematica?

Is there a way to copy and paste code snippets from SE to Mathematica if these snippets are interspersed with text? Like e.g. in Morphing Graphics, color and location in both the question and answer, ...
24
votes
5answers
2k views

Morphing Graphics, color and location

I would like to make a small animation : 1-We start with a random distribution of gray points : ...
14
votes
3answers
1k views

Arguments to If[] are not evaluated

I got bitten by the following: f[x_] := 3*x; g[x_] := If[Log[f[x]] < 0, f[x], 0]; g[x] Out[11]= If[Log[3 x] < 0, f[x], 0] where I thought the call to <...
29
votes
5answers
3k views

Fetching data from HTML source

I want to generate a couple of plots/graphs with Area 51 statistics. Since Area 51 doesn't work with the SE API, I'm forced to find another way to get the information I want. That other way is with <...
17
votes
4answers
346 views

Setting parts of a list

Suppose I have list a = Range[10] {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} in which I want to set some elements to be a list ...
9
votes
1answer
1k views

How to properly DumpSave & Get Global`s symbols inside packages while not touching Global context?

For efficiency reasons I prefer to use DumpSave instead of Save. For ease of access I prefer to save symbols in ...
12
votes
1answer
431 views

Old values are not freed/garbage collected when you re-evaluate an assignment

For this code: (* Cell 1 *) generate := Module[{x}, x = Range[100 * 1000 * 1000]; x]; (* Cell 2 *) g = generate[]; MemoryInUse[] If I evaluate cell 2 repeatedly,...
8
votes
2answers
2k views

How to set the NDSolve method to LSODA

I notice that off all the Method options available for NDSolve[...], LSODA is invoked quite ...
5
votes
2answers
436 views

presenting a real number as real instead of imaginary

I have an equation which results in an answer of the form $\frac{i a}{\sqrt{c-d}}$ is there any way to get Mathematica to present it in it's real form? like $\frac{a}{\sqrt{d-c}}$ I know that I ...
12
votes
2answers
1k views

How to get string representation (like repr in Python)

I have a string variable. I want to obtain another string which contains the representation of the string variable content itself. s = "a \n b" I need to get a ...
7
votes
1answer
3k views

Solve Lagrange multipliers optimization problem

I have two nested solid figure, where $V(a,h,\tau)$ defines the volume and $A(a,h,t)$ defines the surface. The outer solid figure is parametrized in $a_s$,$h_s$ and $t_s$ (they share a common center). ...
23
votes
7answers
3k views

Formatting a fraction as a mixed number

Is there a command that will take a rational number and rewrite it in a mixed-number-like form? That is, I'd like to apply a command to something like 10/7 and get ...
27
votes
1answer
884 views

Publishing results obtained in Mathematica

I've been using Mathematica to solve nonlinear partial differential equations for my doctoral research for the last 2 years or so. I am not an expert in Mathematica or mathematics and I am an engineer ...
7
votes
2answers
684 views

Edge problems in a directed graph

I want to create the following two graphs. So far I tried the following Code ...
84
votes
9answers
17k views

How to make an inkblot?

How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.'s Rorschach demonstration): ...
4
votes
2answers
202 views

Calling a function an unspecified number of times

I would like to be able to call a function an unspecified number of times. That is, I would like the generalization of something like: ...
2
votes
2answers
460 views

MapThread on a nested Map

A simple problem I am facing is here: ...
5
votes
1answer
372 views

Easy Way to Create Trellis Plots in Mathematica

I'm trying to do multivariate statistical analysis on a data set and I'd like to quickly visualize my information first using Trellis-like plots. For example, I'd like to create scatterplots for body ...
12
votes
4answers
2k views

Height-dependent filling color in 3D Data Plots

I would like to have the filling of my ListPlot3D display the same color than the one applied to the data. This question makes sense only in the case of conditional ...
11
votes
2answers
970 views

Avoiding an unresponsive user interface in OS X

I have found that despite Mathematica's numerous updates, each of which have added much functionality, one fundamental issue remains unaddressed: The unresponsiveness of the UI when I make a mistake (...
56
votes
2answers
5k views

What is so special about Prime?

When we try to evaluate Prime on big numbers (e.g. 10^13) we encounter the following issue: ...
26
votes
4answers
8k views

Composition: how to make a day and night world map?

Given the following world images: ...
4
votes
1answer
374 views

Path queries for tree-structured data

Can anyone suggest documentation or tutorials for developing path queries and indices for (XML-like) tree-structured data? Suppose data is organized hierarchically in key->value pairs, eg: ...
5
votes
2answers
457 views

Manipulate Evaluation Order Problem

I seem to be getting some unintended results from a nested Manipulate that I have not been able to resolve. I boiled down the problem I'm having to a simplified ...
7
votes
3answers
3k views

Plotting the open ball for the post office metric space

The post office metric space, $P$ has the distance function defined as follows: $$ d_P (\mathbf{x},\mathbf{y}) := \begin{cases} 0 & \mathbf{x} = \mathbf{y}\\ \Vert \mathbf{x}\Vert_2+\Vert \...
10
votes
1answer
2k views

Handling failed FindRoot calls

I want to handle FindRoot calls which did not converge (e.g "thrown" error message FindRoot::cvmit) ...
23
votes
4answers
1k views

Change the color of a Locator in a Manipulate

How can I change the color of a Locator in a Manipulate? As an example, consider the following. ...
-1
votes
1answer
568 views

variable sized lists and using lists as variables

I am trying to scan a parameter space of varying numbers of parameters subject to some constraints (I am interested in any number of constraints just out of curiosity, but in reality no more than 2 ...
5
votes
1answer
256 views

Validating simplifications analytically

I have a rather complex expression which I would like to simplify and check my work along the way (Mathematica does not simplify very basic things and it is frustrating me). In the following example, ...

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