Questions on correct (or improved) formulation of Mathematica code to achieve particular results. Use this tag (not "symbol") for questions about all those odd @@ /@ # & and ~ characters.

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0
votes
1answer
36 views

Full superset not displayed on Manipulate slider

I wish to incorporate ODE solution with Bondary condition sets: ...
0
votes
1answer
50 views

Help for properly writing simple derivative expression

I need help to write the following expression (only 1 iteration): f(x) = ...some basic function... f[X0,...,Xp] = f(p)(x0) / p! What I have so far: ...
0
votes
1answer
60 views

While Loop Not Looping [closed]

no matter what I do, the following function always returns the first v. This does does not make sense to me at all. It should loop and reevaluate v and only stop when v matches the condition. What am ...
0
votes
1answer
73 views

Position of elements in a list satisfying some criteria - Understanding the syntax [closed]

From this post: if one wants to know the position of the elements of a list that satisfy some criteria, (s)he can do something like that: ...
1
vote
2answers
57 views

How to get the outermost command evaluated first?

I have an expression like ToString[Stuff[...]]. I plan on having the Stuff[...] be manipulated as a string according to the output of other parts of the program. The problem is that Mathematica tries ...
2
votes
1answer
117 views

Array in Sum in Minimize - error “Part specification x[1] is neither a machine-sized integer”

Help please M = 10; z = Array[x, M] {x[1], x[2], x[3], x[4], x[5], x[6], x[7], x[8], x[9], x[10]} ...
2
votes
1answer
68 views

RegionUnion issues with many Regions

The new RegionUnion[] function is just what I needed if only I could get it to work. I have many non-overlapping regions that I will need to use as plotting domains ...
3
votes
3answers
1k views

Superscript prime symbol

x\[Prime] looks like $x_'$, ugly right? Is there a way to make a symbol with prime to look like $x'$? That's what I'm trying right now: ...
26
votes
6answers
584 views

Constructing symbol definitions for With

I would like to be able to define two arrays, one containing symbol names and one containing the values of those symbols, for use in constructs such as With. For ...
0
votes
0answers
42 views

How can I mix // with a function of two arguments? [duplicate]

I often find myself using // when playing around with expressions, but it is always cumbersome to have to switch to the full notation just to apply a function of ...
10
votes
5answers
594 views

Postfix Double Slash Notation with Multiple Parameters [duplicate]

Examples A convenient shorthand that I use frequently is the "double slash" notation to string commands together. For example, I can write: ...
1
vote
1answer
99 views

How a novice user better understand the Q/A [duplicate]

A novice user reading Q/A here: I sometime need to just understand the syntax and meaning of commands exampled here. where is the best place to find it?
0
votes
1answer
91 views

Moment generating function for custom distribution [closed]

For some reason the following fails. I tried everything I could, and I don't know what else to try. ...
5
votes
3answers
293 views

Element-wise list operation on list of lists [closed]

Suppose a function F operates on list A: $$A=\{a_1, a_2,\cdots, a_n\}$$ I have a list of lists, B: $$B=\{A_1, A_2,\cdots,A_m\}$$ Is there a syntax to specify that F should operate on members of B, ...
65
votes
2answers
2k views

Flatten command: matrix as second argument

One thing I could never wrap my head around is how Flatten works when provided with a matrix as the second argument, and the Mathematica help isn't particularly ...
1
vote
0answers
89 views

CreateDialog opening two windows instead of one

I'm having issues working with code from Mathematica 9.0.1 since I've updated to 10.0.0. My previous code involved using packages to set functions, and then those packages were loaded and the ...
2
votes
2answers
836 views

Several functions in one RegionPlot with different grayscale

I try to plot the following, but something seems to be wrong in my code and I can't figure out how to fix it: ...
1
vote
0answers
92 views

SyntaxForm not correctly parsed by FrontEnd

When using TagBox with SyntaxForm, I noticed sometimes it is not well parsed by the ...
1
vote
1answer
74 views

Appending functions to a list [duplicate]

Could someone please explain the difference between these methods, and possibly a nicer way to get the first result? (This is a toy example and in my real program I'd like to use ...
4
votes
1answer
206 views

How to see abstract syntax tree of Wolfram Language expression

I mean, suppose I have this expression: 2 + 2 I want to get something like this: Plus[2, 2] as an output. I've tried FullForm, but this just evaluates 2+2 and returns 4. Is this even possible?
5
votes
3answers
3k views

Matrix Multiplication in context of row and column vectors

I've been looking at some matrices in Mathematica and I've noticed something very weird: They're extremely temperamental when it comes to dot products! For example, if I have the following, ...
5
votes
4answers
215 views

Defining a function with parameters as variables

I have an expression V = (a[1] + a[2])b[1]. How would I define a function of a[1], a[2] and ...
42
votes
5answers
1k views

V10's Operator Forms - what are they good for?

V10 introduces an operator form for several functions perhaps primarily due to their role in queries as part of introducing data science functionality. At first pass it seems a lot of effort to add ...
3
votes
3answers
161 views

Is it possible to use infix notation ~ for functions with one argument or more than 2 arguments?

According to a Mathematica textbook, we can write N[x,n] by using infix notation as x ~ N ~ n. How about other functions with ...
13
votes
2answers
530 views

How to embed an image into a string?

Note: The bug described in the post is in Mathematica 9, and has been fixed in 10.0. The documentation for String contains the following statements: Strings ...
4
votes
2answers
75 views

Why can't I pass in a product of matrices in my modified matrixform? [duplicate]

In attempt to build a function that would work like MatrixForm but would wrap a matrix with brackets, I tried the following function: ...
1
vote
1answer
100 views

How would one minimize with respect to an unknown number of variables?

Say I had a function like the following: f[n_] := Sum[a + Subscript[b, k], {k, 0, n}] Such that ...
5
votes
3answers
423 views

What is the right way to write a function that includes other functions?

I want to include multiple sub functions: $b(x) = 10x$ $w(x) = s + b(x)$ $c(x) = x^2$ into two main functions: $ua(x) = w(x)-c(x)$ $ub(x) = w(x)-c(x)^2$ As a reaction to this answer, I wrote ...
0
votes
1answer
66 views

Combining functions - is this a case for Piecewise?

I have a function $Eb1$ which was the subject of a question I asked recently - you can see it here on stack exchange. Now, in that example it's specified between a boundary $r_n$ and $r_o$ where $r_o ...
2
votes
1answer
62 views

How to joint symbolic expressions together [duplicate]

I want to joint symbolic expressions together to create a another symbolic expressions. one way to do that is as follows: ...
8
votes
1answer
178 views

Extract what symbol is set by SetDelayed, Set, TagSet, UpSet, SetAttributes, etc

One of the recent features of the Mathematica Plugin for IntelliJ IDEA (www.mathematicaplugin.halirutan.de) is a Structure View which let's you see information about several definitions that are done ...
4
votes
2answers
376 views

Scalar product operator of complex vectors

What is the scalar product operator for complex vectors (or matrices) in Mathematica? The usual $Dot[]$ doesn't work. E.g. here is what the Mathematica gives $$\{1,0\}.\{I,0\}=I$$ but the answer ...
0
votes
1answer
256 views

How to output a bat file and execute it?

I tried to write a bat file which helped me rename files. Command to do this in that file is "ren file1 file2" which is equivalent to RenameFile[file1,file2]. ...
0
votes
1answer
190 views

Getting “Null” output from package?

I have a script written to test a package as follows: ...
5
votes
2answers
199 views

Syntax highlighting conflict

I'm trying to syntax highlight this expression: x=$\sqrt{\pi }$//N and from various sources I've learned that x (the assigned symbol) belongs to context Global while the Pi and N belongs to System. So ...
0
votes
0answers
79 views

My “N” turned red randomly [duplicate]

For some reason my N function showed up in red even though I haven't noticed it in that color before. The color actually makes the code much more readable but I just don't know if I should be alarmed ...
1
vote
1answer
50 views

Correctly substituting a matrix into a scalar equation [duplicate]

I am having trouble correctly substituting a matrix into an (originally) scalar equation. For example: A = {{3, 1}, {1, 2}} cp = CharacteristicPolynomial[A, x] ...
4
votes
1answer
101 views

Highlight the same symbol throughout notebook

Once I saw people using Matlab use a keystroke shortcut that made all the same symbols as a selected symbol become blue. I am wondering is there is a function in Mathematica that is similar. If so, ...
8
votes
1answer
111 views

Does the syntax coloring I see indicate a real problem?

I need a behaviour provided by: x = 2; Block[{x = HoldForm[x]}, x] x FrontEnd marks ...
0
votes
2answers
74 views

Setting an element of an array to a value

This may be a simple syntax question, but for some reason I've been having trouble with it. Suppose we have an array arr, and we want to set one of the elements to ...
1
vote
1answer
92 views

Sort lists of vertices {indegrees, outdegrees} by indegree

in = VertexInDegree[F]; out = VertexOutDegree[F]; I want both in and out to be ordered by in. Example: graph has nodes a,b,c with indegrees 1,2,0 and outdegrees ...
2
votes
0answers
51 views

Why is `Cell` > `Convert To` > `InputForm` not invertible?

I sometimes post code to PhysicsSE, and I usually convert it to InputForm first before posting, in order to avoid pages and pages of ...
0
votes
3answers
85 views

Half kth term if n is even and k=n/2?

I am trying to write a function which will perform the equation in the attached image. So far, I have: ...
3
votes
2answers
1k views

How does one specify Neumann conditions for NDSolve?

I have a series of functions defined in my notebook, and then want to use this to solve a diffusion-reaction type equation. At the moment, something like this works: ...
6
votes
0answers
331 views

Do any mainstream text editors support Wolfram Language syntax for highlighting?

Syntax Highlighting for Mathematica on a Blog There is the above, but I'm not terribly excited to install rogue packages. For example on github, I share lots of Mathematica code. I see no way to ...
0
votes
0answers
118 views

Meaning of backtick in conjunction with units [duplicate]

In this fragment from an equation solution the backtick is used twice: ...
27
votes
2answers
1k views

Meaning of backtick in floating-point literal

If I compute, say, 1/3//N, Mathematica displays 0.333333 as the result. When I copy that output to use elsewhere, the paste ...
0
votes
1answer
247 views

How to plot a region bounded by three equations?

I'm very new to this website. I am having trouble plotting a 3 dimensional region bounded by these equations: ...