Questions tagged [built-in-symbols]
Questions related to handling built-in symbols and functions, for example why they behave a certain (possibly unexpected) way.
2
votes
2answers
41 views
DisplayForm problem with pi in FractionBox
The following line produces an output with the text "Pi" displayed instead of the symbol for pi.
All help with an alternative or correction of this would be much appreciated, thank you.
10
votes
1answer
115 views
Who or what is named character Andy?
I suspect \[Andy] meant to represent a staff member, or at least a person of importance.
I tried the F1-"Wolfram Search", Wolfram|Alpha and a simple Mma.SE & ...
10
votes
1answer
116 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
votes
2answers
204 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
votes
1answer
47 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
votes
0answers
32 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 ...
4
votes
0answers
84 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
vote
2answers
66 views
CountryData and RailwayGaugeLengths
Looking to see how to extract out just the length for this search:
...
1
vote
1answer
31 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
votes
0answers
31 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
votes
0answers
40 views
How can I simplify expressions correctly?
the final output of my code gives this expression which i call ttt:
...
1
vote
1answer
30 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
votes
2answers
174 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
vote
1answer
44 views
4
votes
2answers
685 views
Replacing dot by *?
I am unable to replace dot by *.
Replace[a.a, .-> *]
Is there any solution to get this done?
5
votes
3answers
131 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
votes
1answer
87 views
What does the $ sign do? [duplicate]
I saw this uses $, but it was not clear what does it do there.
...
6
votes
5answers
240 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
votes
3answers
518 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
votes
2answers
143 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
vote
1answer
49 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
votes
2answers
138 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
votes
2answers
241 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
votes
0answers
26 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 ...
0
votes
1answer
79 views
Is there an error pertaining to HypergeometricU function on functions.wolfram.com?
If one clicks on the last of the nine formulas on
http://functions.wolfram.com/HypergeometricFunctions/Hypergeometric2F1/17/02/07/
one obtains
Hypergeometric2F1[a, b, c, z] == HypergeometricU[a, b, a +...
1
vote
1answer
52 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
votes
0answers
72 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
votes
1answer
37 views
Question related to IntegerPart
I am having trouble understanding the following result:
Through[{IntegerPart,FractionalPart}[{100 4.02}]]
{{401}, {1.}}
...
6
votes
2answers
643 views
How to take top 10 built-in function
WolframLanguageSymbol has a property named Frequencies, such as
...
4
votes
1answer
82 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
votes
1answer
62 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
vote
1answer
77 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
votes
1answer
79 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
votes
3answers
299 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
votes
1answer
220 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
vote
0answers
44 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, ...
0
votes
1answer
121 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
votes
1answer
61 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
votes
1answer
181 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
...
1
vote
1answer
146 views
Implement edge contraction function which respects vertex weights
It seems that built-in EdgeContract function doesn't work properly with weighted graphs, to be more precise, I mean that if I'm going to contract edge $e$ which ...
3
votes
4answers
175 views
What is the inverse of the Position function?
What is the inverse of the Position?
I have an array which contains the positions of elements and I want a function which returns an List which contains 1 where ...
2
votes
1answer
94 views
How does one plot an oblique/slanted cylinder within the plot range?
A Cylinder does not seem to have an option to make it oblique. A Tube has an oblique center but does not seem to have an option to make the end caps oblique. One could plot a cylinder or tube that ...
0
votes
1answer
53 views
Why the export the Graphics or Image to local file [closed]
I note the Put cannot export the Graphics or Image,I mean this code will be failure.
...
5
votes
4answers
270 views
Mean of a list of lists (vector) with missing values
I understand, from Calculating the mean of a list with NaN values, that one can preserve structured data with missing values, and still calculate a mean, using ...
7
votes
1answer
316 views
Geometry computations add-on for Mathematica?
I came across the problem of calculating the circumcenters of triangles symbolically within another algorithm (as well as possibly doing other similar geometry computations). I was hoping Mathematica ...
10
votes
2answers
414 views
Is it safe to Unprotect everything? What are the implications?
What is the reason for built-in symbols to be Protected?
What happens if I Unprotect built-ins and add my own ...
1
vote
1answer
114 views
Having trouble defining a function with head Superscript
I wish to define a function in the following form,
...
5
votes
1answer
76 views
Unexpected result of Clip
A simple question. Here Clip works as documented:
Clip[0.5, {0, 0}, {0,1}]
(* 1 *)
Values larger than 0 are replaced with ...
24
votes
2answers
1k views
List of symbols without built-in meaning
Is there a list of all symbols with special display forms but no built-in meaning? That is, operators that are described in the tutorial Operators without Built-in Meanings?
4
votes
1answer
87 views
Internal function overload when calling ReadString on a fresh kernel
Problem description:
I am capturing all FE messages to redirect them to my own window while blocking them from showing in the evaluation notebook using this method by rcollyer. It works great, but I ...
