11
votes
3answers
884 views

Monitoring progress of long calculations

I've came upon a few methods of how to display "processing" information while Mathematica is running. But, from what I've understood, this only works in between lines of codes. Is it possible to ...
11
votes
1answer
675 views

Example program for calling Mathematica from C

I want to call Mathematica from a C program. Suppose I have two numbers x = 2 and y = 3. I want to define ...
11
votes
3answers
566 views

How to add lists with unequal length?

Given lists of unequal lengths, I want to add them together element-wise, treating missing elements as zero. For example, {1, 2, 3} + {a, b} + {x} should give ...
11
votes
1answer
336 views

Using Apply inside Compile

In this great answer a compiled version of the Nelder-Mead algorithm is presented. Since it works on arbitrary dimensions (i.e. arbitrary number of arguments), it has to use apply on the objective ...
11
votes
3answers
745 views

Image levels: how to alter 'exposure' of dark and light areas?

I was working with some less than ideal photographs, and wanted to adjust them before continuing. I wanted to raise the levels of the very dark areas and lower the levels of the very light areas. I ...
10
votes
1answer
272 views

StringReplace, ReplaceAll and Rule interact in a bizarre way

I have the following pair of things: ClearAll[foo, labeledFoo]; labeledFoo = {"FooBarBazQuux", foo}; This works like you'd expect: ...
10
votes
1answer
513 views

How to run mathematica scripts without initializing the kernel every time

I have written a Mathematica script that is to be run periodically on a Raspberry Pi. The code takes about 3 seconds to execute if I test it in a CLI Mathematica session. However, when I execute the ...
10
votes
1answer
1k views

Drawing a graph with specified edge lengths

I was wondering if it was possible to ask Mathematica to draw a graph provided some set of vertices: $(v_1, ..., v_N) \in V$ connected by $M$ edges $(e_1, ..., e_M) \in E$, where the length of each ...
10
votes
1answer
634 views

Explain a Mathematica winning one-liner

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10
votes
1answer
287 views

Preserving indentation when creating a new line (when editing in a package)

Background: This is the third question in a row of questions about how to make editing packages in the front-end much more bearable (the other two are here and here). It seems that the front end is ...
9
votes
1answer
2k views

Wolfram Light Weight Grid and parallel computing

I have attempted to set up and use the Wolfram Lightweight Grid Manager so I can do parallel computing from Mathematica using 2 remote processors on another machine on my local network. My ...
8
votes
5answers
2k views

Something faster than Do loops with AppendTo

I am an "old" programmer used to Fortran and Pascal. I can't get rid of For, Do and While ...
8
votes
3answers
894 views

How do I create a package from an existing notebook?

I have a notebook containing some functions, for example: f[x_] := 2*x g[x_] := x^2 Now I would like to convert this notebook to a package, ...
8
votes
2answers
726 views

How to declare a 3D vector variable?

How can I do vector calculations without telling Mathematica the vector entries? I have very many arbitrary linear combinations in $\mathbb{R}^3$ which I want to perform some general calculations on ...
8
votes
2answers
9k views

Make a scatter plot from two lists

I have two lists of values xx = {0.1, 0.3, 0.35, 0.57, 0.88, 1.0} yy = {1.2, 3.5, 4.5, 7.8, 9.0, 12.2} I want to make a scatter plot (list plot) with xx as x ...
8
votes
5answers
418 views

Efficiently finding the positions of a large list of targets in another, even larger list

I have a big list. It contains nearly 60,000 sub-lists. It's structured like bigList = {{x1,y1,z1},{x2,y2,z2},{x3,y3,z3},.....,{x60000,y60000,z60000}}; I have ...
8
votes
2answers
611 views

How to properly handle mutual imports of multiple packages?

I'm new to the mathematica platform and I am developing a simulation framework as my first exercise and have been tearing my hair figuring how to make packages interact with each other. Ill explain a ...
8
votes
5answers
813 views

can the color in MeshStyle be specified by a ColorFunction, such as “SunsetColors” for example. If so, what is the correct syntax?

This is an example given in Help: Plot3D[Sin[x y], {x, 0, 3}, {y, 0, 3}, MeshStyle -> Gray] Could this be changed to something like ...
7
votes
3answers
180 views

Converting StringJoin to StringForm inside Hold

Let's say I have a piece of code: Hold[{code1, "asdad " <> ToString[testa] <> " adsd " <> ToString[testb], code2}] (*MWE ofc*) ...
7
votes
1answer
262 views

Module variable scoping in Scheduled Tasks?

I ran across a scoping puzzle while experimenting with ScheduledTasks, and I'd be grateful for an explanation from the sages here. I found a workaround by intuitive horse sense, but was unable to ...
5
votes
1answer
2k views

Methods for NonlinearModelFit

I am using NonlinearModelFit for a thesis project. I get quite different results if I change the Method to LevenbergMarquardt or QuasiNewton or ConjugateGradient ...
5
votes
1answer
427 views

Label area on plot

I created the following plot using Mathematica: ...
4
votes
4answers
5k views

How to export data files using specific format

Very often, I have to export data files from Mathematica. These output files contain several columns and hundreds of lines with data. For the sake of the question let's create a sample list ...
3
votes
1answer
2k views

Methods to speed up numerical NDSolve, NIntegrate,

I am not very used to do numerical simulations on Mathematica. Do you have any ideas how to improve i.e. speed up my code? ...
28
votes
1answer
379 views

How to save ChemicalData queries so that they are available immediately on notebook load?

If I put some viscosity (or density, ...) lookups in my notebook, such as: ...
27
votes
4answers
3k views

How to find the period of an arbitrary mathematical function?

Is there a function to find the period of an arbitrary (possibly complex) function in Mathematica?
25
votes
1answer
409 views

Tool to locate bloat in a notebook?

In developing a notebook, I often find I have created a very boated file that takes a long time to save. I would like to slim it down. It is usually the result of graphics and images, but they may be ...
19
votes
11answers
1k views

Generating an ordered list of pairs of elements from ordered lists

I have a pair of ordered lists. I want to generate a new ordered list (using the same ordering) of length n by applying a binary operator to pairs of elements, one from each list, along with the index ...
18
votes
6answers
2k views

Visualize Pascal's triangle and other triangle shaped lists

How can Pascal's triangle be visualised like this in Mathematica? Or more generally, how can a 'triangular' list like {{1},{1, 1}, {1, 2, 1}} be visualized in ...
17
votes
6answers
630 views

How do I replace a missing value in a column with the value immediately above throughout a table?

I have a large table (7000 rows × 17 columns) of terse textual data. In many of the columns, empty entries have been replaced with "." as a marker. Working from the top of the columns downward, I want ...
17
votes
1answer
2k views

Global precision setting

Coming from Maple I do not understand how the precision for numerical computations in Mathematica is specified. I understand that there are various options to commands such as ...
17
votes
6answers
1k views

Using patterns in pure functions

Pure functions may be handy if you don't want to assign your function a name. For example I would calculate $x(x-1)$ for some numbers $x$ by ...
16
votes
2answers
422 views

Are later versions of the Front-End compatible with older Kernels?

At my graduate school, all of the clusters still use version-6, and I only have version-7 and version-8 installed on my computer. I would like to use those machines remotely. Are either of the ...
15
votes
1answer
602 views

How to work with characters from CJK Unified Ideographs Extension B correctly?

Background: Recently I'm trying to deal with some Chinese characters which belongs to the CJK Unified Ideographs Extension B block. The motive comes from some further interest following a former ...
14
votes
6answers
1k views

Shuffle product of two lists

I want to do the following: I have two lists {a_1,...a_n}, {b_1,...,b_n} and I would like to build now all shuffles out of this. This means all unions of these ...
14
votes
1answer
279 views

Is there a way to get AbsoluteTime to correctly report absolute time differences?

Absolute time supposedly reports the "total number of seconds" between two dates, but it does not. For example because of the leap second applied at 2012-06-30T23:59:60Z ...
14
votes
2answers
445 views

Determining the default Method used in optimization and root-finding algorithms

Is it possible to extract the Method which is used in functions like NMinimize, FindRoot, ...
14
votes
3answers
1k views

NSolve gives additional solutions that don't satisfy the equations!

I am trying to solve the following polynomial equations in Mathematica: ...
14
votes
4answers
2k views

Reflect a Plot Object

I have a relatively simple operation I'd like to perform on a plot: I would like to reflect the plot across the x-axis. I do not have any tick labels, so making sure that the labels are not themselves ...
14
votes
3answers
674 views

Gridlines of a framed plot with a background cannot be white?

Looking at this question, I am reminded of a problem that I was never able to solve with obtaining a particular plot format. The issue is that GridLines sit behind ...
13
votes
1answer
207 views

Potential pollution of Global` context in fresh kernel

Bug introduced in 10.0.0 and fixed in 10.0.1 If I evaluate, with a fresh kernel Names["Global`*"] I get {"rhs", "z"} ...
13
votes
2answers
546 views

Diagonal Tick Marks

I would like to draw diagonal tick marks around a plot, and simultaneously rotate the tick labels as well. I've mocked up what this would look like: Is there an easy way to do this in Mathematica? ...
13
votes
4answers
705 views

Strategies for avoiding and handling shadowing

When dealing with namespaces in Mathematica (BeginPackage, $ContextPath ...) one is unavoidably confronted with the problem of ...
12
votes
1answer
249 views

Orderless pattern matching

The MMA docs state that "In matching patterns with Orderless functions, all possible orders of arguments are tried". Why then does the following not work? ...
12
votes
1answer
304 views

10.0.2 mapping Association to Dataset warning

In 10.0.2 ExampleData[{"Dataset", "Titanic"}][All, <| "gender" -> #sex|> &] Outputs the expected result, but also throws: MapAt::partw: Part ...
12
votes
3answers
307 views

In InputField, how to prevent Shift-Return from generating a new cell?

When running the following in a notebook (not a deployed CDF file), it can sometimes be annoying that accidentally pressing Shift-Return breaks out of the user ...
12
votes
1answer
337 views

Automatic formatting of isotope symbols in a text cell

InputAutoReplacements is an obvious choice for formatting isotope names in text cells. I'd like to be able to type "1H", for ...
12
votes
1answer
802 views

Finding a Specific Line in a Package

In a package I am developing, I accidentally left this line Protect[ uncompleted prior to running the package. Mathematica produced this error message ...
11
votes
4answers
574 views

How to implement dual numbers in Mathematica?

I wonder how can I implement dual numbers in Mathematica, so that all functions work well with them (as with complex numbers). Particularly, for each function $f$, ...
11
votes
2answers
214 views

Globally loading packages while using a CellGroup as the default context

I have a notebook I wish to set up where the sections are conceptually related to each other. But, I wish to isolate them from each other programmatically, so that they do not interfere with one ...

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