The tag has no wiki summary.

learn more… | top users | synonyms

1
vote
1answer
48 views

Why does WordData fail to find “PartsOfSpeech” when given a list of two words?

I have the following sample code. StringSplit["a test string", " "] Thread[WordData[%, "PartsOfSpeech"]] The output I get is: ...
4
votes
1answer
147 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?
7
votes
2answers
258 views

When must I use the Return function?

In a comment to my answer to this question, QuantumDot asks, "Where can I find more information on when I must use the 'Return' function?". I found this too deep a question to be answered by leaving a ...
29
votes
1answer
534 views

Incompatible Changes since Mathematica Version 7?

There is documentation of the incompatible changes made to Mathematica with each major release: Incompatible Changes since Mathematica Version 1 Unfortunately that documentation simply stopped ...
20
votes
2answers
433 views

Why is Query so much slower than Part?

Time for another of these(1),(2) as yet another new-in-10 function appears to have poor performance compared to older alternatives. This time: Query appears to be ...
6
votes
2answers
176 views

Why does Mathematica appear to change the head of certain expressions?

I don't know if the question trivial or not (if so I will delete it), but here is what I have: I know that x x (* x^2 *) Looking at the full form gives ...
0
votes
1answer
93 views

Need help in understanding code [closed]

I am just beginning with Mathematica. I have received this code to study. I am not able to follow this particular section. I have tried looking it up on many forums, with no answer. Can you help? ...
11
votes
2answers
194 views

Can't get Append to append a record (association) to a dataset

The Documentation Center item, Computation with Structured Datasets, implies that Append has been extended in V10 to work with datasets. But not on my computer. (I ...
32
votes
2answers
625 views

Why is the new PositionIndex horribly slow?

Disconcertingly I have discovered that the new (v10) PositionIndex is horribly slow. Using Szabolcs's clever GatherBy inversion ...
13
votes
1answer
260 views

Shorter syntax for Fold and FoldList?

I find it tedious to write out the following: a = {1, 2, 3, 4}; Fold[f, First @ a, Rest @ a] f[f[f[1, 2], 3], 4] It ...
4
votes
1answer
107 views

Multiple down-values with exactly the same lefthand side

I was working on an answer to this question, when I was sidetracked by what I bring up here. I wanted a function, which when given a string representing a binary number, would convert the string to a ...
2
votes
1answer
41 views

Is the use of Block to temporarily override definitions inherently unsafe? [duplicate]

This may have been discussed before, if so, please let me know. Consider the following example: x = 5 Dynamic[{Clock[], x}] This will always display the ...
3
votes
0answers
204 views

Is Wolfram Language suitable for building web applications? [closed]

My goal is to find a technology which will afford me to build web applications (e.g. simple social networking site) as quickly as possible (with as little code as possible). I was impressed by Stephen ...
25
votes
4answers
422 views

What's the difference between Inactive and HoldForm?

In version 10, Mathematica not only added Inactive / Activate but also highlighted this change in the "New in 10" page (in Core ...
1
vote
1answer
61 views

Why is Return not forcing an exit from my function? [duplicate]

Here is simplified version of my code that exhibits the behavior troubling me: ...
50
votes
3answers
1k views

How to make use of Associations?

I have been curious about it for long. Now that Mathematica 10 arrives, I think it's time to ask the question: How the new Association data structure would be used ...
8
votes
3answers
600 views

Why are functions called first-class objects in Mathematica?

I've heard lots of people say a function is a first-class object in Mathematica. "Everything is an expression, including function." "There is no distinction between functions and data." Having read ...
7
votes
3answers
207 views

Implementing key-value associations in Mathematica 9 with inexact numbers for keys

I'm not sure of what type of problem my issue falls into, so I haven't been able to search forums with any success. If this has already been solved then my apologies! Essentially I'm trying to set a ...
1
vote
2answers
119 views

Unexpected Plot3D behaviour

The following illustrates what appears to be an incorrect Plot3D for this polynomial. I have forced the function to complex argument, changed ranges. In contrast, ...
0
votes
3answers
89 views

Identifying the symbol which has a specific value

I'm writing a program that will solve the value of 1 variable in a 4-variable equality equation, but the variable to be solved will depend on the user's input to the program. This is what I've come ...
2
votes
2answers
97 views

What is wrong with my use of Flatten? [closed]

Why does Flatten[f[g[a, f[b]], f[c, d]]] result in f[g[a, f[b]], c, d] I expected the answer to be ...
2
votes
1answer
128 views

Euler's method for a 2nd order ODE

This is my first post on this site. Also, I'm new to Mathematica. I'm trying to solve my first problem with Mathematica. It's about solving a 2nd order differential equation. I dont have the explicit ...
2
votes
1answer
62 views

Can a Symbol own OwnValues that don't evaluate when it's the head of an expression?

I believe this a question that most of us have encountered when we were beginners but forgot when we got more familiar with Mathematica. We know the notation $y=y(x)$ for functions, where $y$ here ...
0
votes
0answers
75 views

Using Wolfram Language without Raspberry Pi [duplicate]

What are the different ways I can start using Wolfram Language even though I dont want to use Raspberry Pi? Are there any convenient ways? I actually have a raspberry pi but I am trying to find ...
2
votes
4answers
305 views

How to completely delete the head of a function expression

Is there any way to completely remove the head of an expression function? For example, how would I remove the head Cos from ...
0
votes
0answers
55 views

?function-name does not return function help

For some reason when I use ?function-name to ask for help on a function, I got a very clinical breakdown of that function with its options and attributes instead of the blurb about the function: To ...
3
votes
1answer
88 views

How can I extract all the non-number symbols from an expression [duplicate]

If I have an expression, let us say something like this: Cos[3 x] + π/cofe Exp[y^(c z)] how can I get all non-number symbols in the expression which are: ...
0
votes
0answers
28 views

Unexpected results from Thread [duplicate]

I've run into an issue where threading two lists with a generic function, f: Thread[f[{{1,1}, {2, 2}, {3, 3}}, {4, 5, 6}]] ...
0
votes
0answers
73 views

Nested For loop with NDsolve

I am solving two simple differential equation using NDsolve. ...
4
votes
2answers
146 views

Solve a system of M equations without specifying M

This post has been edited heavily in response to the comments: my initial question was very confusing. I am trying to write my game-theoretic model in Wolfram Language. There is only one remaining ...
0
votes
0answers
92 views

Issue with Set function

Tables often come with column headers. Indexing the columns with the header is a natural thing to do. Although a proper dictionary is the usual solution in such a case, I find it often practical and ...
4
votes
2answers
172 views

How can I avoid getting the error message Goto::nolabel in my code?

If anyone could suggest a reason why Label[begin] ... Goto[begin] would return Hold[Goto[Begin]], and (better) how can I avoid ...
0
votes
0answers
85 views

Mathematica function Det has unexpected behavior

I am using Mathematica "Kernel" -> {"Version" -> "9.0 for Microsoft Windows (64-bit) (January 25, 2013)", "ReleaseID" -> "9.0.1.0 (4055652, 4055188)" on a Win 7 machine. The file listed below uses ...
3
votes
1answer
349 views

Is there the full Wolfram Language in Mathematica?

Today I read the new entry on WolframBlog with all it's nice little demos. I was realy interested in those with astronomic informations, but trying these with my own Mathematica I was irritated: ...
1
vote
1answer
80 views

Why there is no SlotSequence (##) form analogical to #[[ ;; n]]

I'm aware that this may be closed as offtopic but there are people around with "offtopic" knowledge :) So, in List context we can: ...
1
vote
0answers
55 views

Function behavior based on Head

I'm figuring how to implement a function behavior based on the Head of its argument. I mean ...
1
vote
0answers
46 views

Type Vietnamese in Mathematica

I type Vietnamese using UTF-8 Encoding but Text Display got error. How to type Vietnamese, Chinese in Mathematica. Please help me.
2
votes
0answers
97 views

How is Wolfram Language different than regular Mathematica? [duplicate]

From all I can see there seems to be no difference between "Wolfram Language" and regular Mathematica. Is Wolfram just a marketing rebranding of Mathematica or is there a new capability I am missing?
1
vote
1answer
60 views

Behaviour of Simplify when used with ArcTan and ComplexExpand along with assumptions

I am trying to simplify the slope of vectors with symbolic coordinates {x,y} using ArcTan[x,y] I am working with real X and Y I tried the following : ...
7
votes
1answer
230 views

Defining my own invisible operator

There are some invisible operators in Mathematica (\[ImplicitPlus],\[InvisibleTimes],...
5
votes
1answer
136 views

Problem with With [duplicate]

I am puzzled byWith. it does not seem to work. Please see example below (I have also used Evaluate and ...
3
votes
1answer
99 views

How to Override the Head of a Symbol

I was wondering if it is possible to override the head of symbols/operators. As a motivating example if I run: Then Ket will be returned. But lets say I want Bob to be returned instead of Ket. Is ...
0
votes
2answers
71 views

How can I make my output to be added to an existing list?

v = {{0, 0, 0}, {1, 0, 0}, {1, 0, 1}, {0, 1, 1}, {1, 1, 1}} For[i = 1, i < 6, i++, For[e = 1, e < 6, e++ 1, Print[Mod[v[[i]] + v[[e]], 2]] ]] I ...
10
votes
0answers
279 views

Create a new infix operator [duplicate]

It is well known that the infix operator @@ is used as a short form of Apply. For example, both ...
3
votes
0answers
48 views

Precedence of defined functions [duplicate]

When I define functions in Mathematica like: f[x_] := 3 f[x_Integer] := 6 How is the value of f[6] determined? It seems to ...
0
votes
1answer
68 views

Scheduled tasks not preserving order with Dynamic?

In studying the last Basic Example in the documentation for StartScheduledTask, namely ...
6
votes
1answer
109 views

Mystery with ValueQ

Consider the following ClearAll[jd]; ValueQ[jd] We expect False and get it. Now consider ...
5
votes
1answer
150 views

Treat all variables as local in a module [duplicate]

In most languages, any variable defined inside a function is considered local. ...
22
votes
2answers
917 views

Is Mathematica comparable to C++ for creating standalone applications?

At my university, I have a yearly essay. I'm allowed to use any technology for implementing it. I've been coding it in C++ with Qt. I thought of about Wolfram Mathematica because I have some ...