Questions tagged [built-in-symbols]

Questions related to handling built-in symbols and functions, for example why they behave a certain (possibly unexpected) way.

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1answer
68 views

Why do atomic objects like 56 have a head if they're supposed to be, well, atomic?

This question follows from this one I made earlier. If you ask for FullForm[4] you will get back 4, and that's fine. ...
3
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2answers
101 views

What's the difference between 56 and Integer[56]?

I'm trying to grasp how to Wolfram Language uses symbolic expressions for everything. The concept of doing so makes sense to me, but the language doesn't behave how I predict. I understand how ...
2
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1answer
93 views

Automated (lazy) method to make custom (key-input) shortcuts (not menu items) for letter-like symbols? [duplicate]

The Problem: I don't know about you, but every time I am trying to do analytical work in Mma, it is rather difficult/cumbersome for me to type the following, here specifically for ...
0
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1answer
38 views

Symbolic Resultant Too Slow/Keeps Running

Evalutation of the following cell, which includes the symbolic resultant, of two univariate polynomials in $x$, with parameters $a,b,c$ for the first polynomial (of degree 4) and parameters $d,e,f,g$ ...
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1answer
47 views

JoinAcross with multiple associations

I would like to use JoinAcross to combine several lists of associations. Extending an example from the documentation, I'd like to do this: ...
0
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1answer
30 views

Apply Expand only to parts of expression

I have the following term: term = (x AngleBracket[x (-x+Sum[v'[y[j]],j])])/AngleBracket[x^2]+Sum[v'[y[j]],j]; term //TeXForm $\frac{x \left\langle x \left(\sum ...
4
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2answers
207 views

Underflow error General::munfl from E^x instead of Exp[x]

In contrast to earlier versions, Mathematica 11.3 and 12.0 generate lots of underflow errors from my code, e.g. ...
0
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0answers
23 views

Redefining the inbuilt function and its derivative [duplicate]

I want to redefine the DiracDelta functions and its derivatives. I am successful at redefining the DiracDelta function but not ...
2
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1answer
80 views

How I can get glyphs from a fraktur font and use them as identifiers?

I would like to use the fraktur-S ($\LaTeX$: \mathfrak{S} $\mathfrak{S}$; Unicode: "U+1D516" 𝔖) as a variable name in Mathematica, but pasting the Unicode ...
2
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2answers
72 views

Replacing with pattern on built-in symbols?

I have: f[a, b] /. f[x__] -> g[x, 0] // InputForm (* Out: g[a, b, 0] *) Which is what I expect, but when I use a built in symbol instead of ...
5
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1answer
61 views

How to reset a built-in symbol to its default definition?

I'm trying to add functionality to some of Mathematica's built-in functions in a package I'm building. I'm not trying to overwrite any functionality—just add it where it isn't already defined. I ...
4
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2answers
92 views

DisplayForm problem with $\pi$ in FractionBox

The following line produces an output with the text "Pi" displayed instead of the symbol (greek letter) $\pi$. Code line: FractionBox[π,2] // DisplayForm ...
10
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1answer
228 views

Who or what is named character Andy?

I suspect \[Andy] was meant to represent a staff member, or at least a person of importance. I tried the F1-"Wolfram Search", Wolfram|Alpha and a simple ...
10
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1answer
137 views

Why does Success[…][key] work and Failure[…][key] doesn't work?

I'm trying to figure out what is a quick way to add error reporting to my user defined functions. I was experimenting with Success and ...
3
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2answers
245 views

How to find the list of all the elementary functions in mathematica?

Is there any command to give me the list of all the embedded elementary functions in Mathematica like Cos Sin Cosh Sinh Log and so on?
3
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1answer
52 views

Is using Length more efficient than using === as stopping criterion?

I am using NestWhileList[ f[#, elems]&, pairs, Length[#1]<Length[#2]&, 2, Infinity, -1 ] to generate all suitable subsets from ...
0
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0answers
39 views

Create library of custom functions [duplicate]

I have been trying to create a library of custom functions that I could just call at the start of every notebook. For instance, say I want the following functions to be part of the Library, or even ...
5
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0answers
99 views

Not comprehending PowerMod

Bug introduced in 10.3 or earlier and persisting through 11.3.0 or later The bug is not present in 10.0. By definition, PowerMod[a, 1/r, m] finds a modular rth root of a mod m. Here's a pair of ...
1
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2answers
68 views

CountryData and RailwayGaugeLengths

Looking to see how to extract out just the length for this search: ...
1
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1answer
34 views

From algebraic symbols to symbolic functions

i have a code which gives an output of this kind: rrr=2*f+1; Now i define a simple function: f[x_]:=3*x+2; How should i do ...
0
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0answers
33 views

Mathematica does not recognize NestGraph

When I try to use the built-in command NestGraph, Mathematica doesn't recognize it. So it just outputs whatever I put in without doing anything. Do I need a special package for NestGraph?
0
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0answers
43 views

How can I simplify expressions correctly?

the final output of my code gives this expression which i call ttt: ...
1
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1answer
58 views

Substitution of expressions for the output

I have a code which gives this kind of output : W = Sum[v[j]*b[j], {j, 1, 3}]; AA = (v[1]*b[1] + v[2]*b[2] + v[3]*b[3])*2 + 3 ; I know that if i want to ...
3
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2answers
175 views

Transferring DownValues

I have a code in which I define something like this: cc[1, 2] = 1; cc[2, 6] = 12; cc[3, 7] = 3; After some manipulation I define a sort of temporary variable ...
1
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1answer
45 views

Setting to zero non defined array variables

I have a situation like this (for example): ...
4
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2answers
693 views

Replacing dot by *?

I am unable to replace dot by *. Replace[a.a, .-> *] Is there any solution to get this done?
5
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3answers
165 views

Power Function and Non Commutative Multiply

I'm trying to figure out the best way to define a Power function for non commutative multiply that retains some of the regular features of the ordinary power function. As of now, what I've been ...
3
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1answer
91 views

What does the $ sign do? [duplicate]

I saw this uses $, but it was not clear what does it do there. ...
6
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5answers
253 views

First evaluate in place all subexpressions matching pattern before substituting result

ReplaceAll[expr, {patt1:>rhs1, patt2:>rhs2, …}] works by looking for and making all possible replacements of subexpressions in ...
7
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3answers
521 views

Is there a built-in function to get the centroid of a table?

Suppose I have a table with some data that are 'lumped' around some central location, such as the dummy example ...
6
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2answers
158 views

How to create non-rectangular array with Array?

From the answers to this question, I learned that the recommended way to construct a symbolic sum of terms in an expression is to use Array. But I'm having a ...
1
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1answer
50 views

Low level built-in function to transpose expression (not array) [closed]

I have an expression like this F[G[1, b], G[3, y], G[4, y], G[5, u]] that I would like to Transpose to obtain ...
7
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2answers
156 views

Constructing expressions using Sum vs Array[… Plus] vs Plus@@Table[…]

For constructing a sum of terms which are symbolic, I noticed that in addition to ...
7
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2answers
294 views

How to obtain list of Installed Packages loadable by Get (<<)

When Get["MyPackage`"] is executed, Mathematica looks for a package in $UserBaseDirectory/Applications, and it does, it will ...
0
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0answers
27 views

Built-in function to know if a list is inside another? [duplicate]

For example, if the function is f[a_List,b_List] then in f[{a,b,c},{a,b}] and ...
1
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2answers
116 views

Is there an error pertaining to HypergeometricU function on functions.wolfram.com?

If one clicks on the last of the nine formulas on the Wolfram Functions site, one obtains ...
1
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1answer
57 views

any possible meaning to a “terminal” slash (/)? [closed]

I've been directed to the web page http://functions.wolfram.com/07.31.16.0001.01 The first statement in the formula is ...
4
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0answers
99 views

Crossing a symbol like p, similar to HBAR

Is it possible in Mathematica to cross a symbol like p, similar to h-bar, used to denote the Planck constant? Picture in case of font problems: In case of h, we have HBAR, inputted as ESC-hb-ESC ...
2
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1answer
39 views

Question related to IntegerPart

I am having trouble understanding the following result: Through[{IntegerPart,FractionalPart}[{100 4.02}]] {{401}, {1.}} ...
6
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2answers
646 views

How to take top 10 built-in function

WolframLanguageSymbol has a property named Frequencies, such as ...
4
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1answer
84 views

Is there a PartDelete like there is a TakeDrop

TakeDrop is nice because after taking a subarray, it also returns the remaining subarray. But it is limited in that the part specification can only be ranges, and ...
2
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1answer
63 views

Get polynomial terms

Is there a command equivalent to that of Coefficient to get the terms of a polynomial which are a power of the variables? For example: func[(x^3 + x)^2] {x^2, ...
1
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1answer
78 views

Functions aren't executed

Can't figure out why Mathematica doesn't want to execute built-in functions? What can be wrong? Input: ...
-1
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1answer
90 views

meaning of variable equal dot [closed]

I came across a program which I have written in a simplified form. For[i=1,i<100, i=i+1; func = a x^i; func=. ]; What is purpose of "func=."?
4
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3answers
324 views

Faster trace of product of two matrices

I noticed that for the computation of the trace of a product of two matrices, using Tr[Dot[A,B]] is a little inefficient. Dot ...
9
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1answer
244 views

Table of precedence values for all System` symbols

Has anyone created a table listing the precedences for all symbols? Also, it would be nice if there were a function that for a given precedence value or interval, returned all the symbols with that ...
1
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0answers
51 views

Wigner-D in MMA

Can some nice MMA fellow explain to me why buit-in Wigner-D function is defined as $D_{mm'}^{J} = e^{i(\phi m+ \gamma m')} d_{mm'}^{j}(\theta)$ against the convention, used by most people on Earth, ...
1
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1answer
140 views

How to prevent simplification from Times to Power?

By default, Mathematica simplifies Times[f[x],f[x]] as Power[f[x],2]. In most cases it's fine, but I happen to have a code where ...
4
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1answer
62 views

What does $UseTextSearchQ do?

Mathematica 11.2 features a new built-in symbol in the Global` context: Global`$UseTextSearchQ What does it do, and how do I ...
9
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1answer
193 views

1 is not the SameQ as Null, but why might 1 be Equal to Null?

The command SameQ[1, Null] returns False which is what I would expect, but the command ...