Questions on attributes of functions.

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2
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0answers
54 views

Documentation on the attribute OneIdentity [duplicate]

The documentation on the attribute OneIdentity says OneIdentity is an attribute that can be assigned to a symbol f to ...
0
votes
0answers
20 views

How to protect variables or functions only for outside? [duplicate]

I have some private variables within my package. Begin['Test`']; Begin[`Private`]; var = 0; f[x_]:=(var = x); End[]; EndPackage[]; When I execute some functions ...
2
votes
2answers
122 views

make trace of a matrix listable?

I have a list of 2 by 2 matrices and I want the list of their traces. I have been using Map[Tr,mylistofmatrices] But I wonder if there is a way to make ...
4
votes
2answers
134 views

How do I display function application with square brackets in traditional form?

If I type C[x, y] // TraditionalForm I get something that looks like C[x, y] But if I type ...
7
votes
2answers
199 views

Built in function without Attributes Listable works as if it has Attributes Listable

Can Built-in function works as if it has Attributes Listable even if it doesn't have that ...
5
votes
1answer
175 views

How to understand the difference between Sqrt and Log after ClearAll them

I came across this post, here I change the last line of the code Unprotect[Sqrt]; Sqrt[x_] = "blahblah"; Protect[Sqrt]; Sqrt[2] "blahblah" ...
7
votes
2answers
203 views

Given the OneIdentity attribute why is GCD[a] evaluated to GCD[a]?

GCD has attribute OneIdentity so I expected GCD[a] being evaluated to a?
12
votes
1answer
255 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? ...
4
votes
1answer
70 views

How Unevaluated works Through its Attributes?

Check this example: ...
4
votes
1answer
96 views

Slowdown of Flat attributed function

I was trying to write an associative function f using the attribute Flat. ...
0
votes
1answer
26 views

Numeric-type attributes for symbols (analog of NumericFunction)

Is there an attribute for symbols that makes NumericQ give True? For example Pi and ...
12
votes
2answers
179 views

Listable functions thread over Associations; is this documented?

Thanks to a somewhat misapplied use of MapThread I learned of this behavior: ...
12
votes
2answers
255 views

How to restore function attributes to default

Adding an attribute to a function is easy and clearing attribute is easy also. But I don't know really how to restore the attributes of a function to its defaults. All I do is quit the kernel or close ...
4
votes
1answer
112 views

Listable on first level [duplicate]

I have some function which take List as input. f[l_List]:=someActions[l] I need apply this function to a list of lists. Now I ...
2
votes
1answer
579 views

Why is either Listable or HoldFirst not working?

Starting with a fresh kernel, I evaluate the following: ...
2
votes
1answer
193 views

Plotting attributes of vertices in WattsStrogatzGraphDistribution[n, p, k]

I have a graph WS = RandomGraph[WattsStrogatzGraphDistribution[n, p, k]]. I need to plot several characteristics of each v: the ...
8
votes
3answers
429 views

How to protect functions in a Mathematica Package?

I'm writing a Mathematica Package with many functions, but only two can be seen/public. I have: ...
9
votes
1answer
116 views

Why does $Failed have attribute HoldAll?

Why does $Failed have attribute HoldAll? Are there typical situations where $Failed is ...
9
votes
2answers
299 views

Mathematica: How to create a function that returns a property similar to how LinearModelFit works?

I'm trying to write a custom function in Mathematica, myFunc[x]. I want to be able to define properties of the function so that the user can call ...
5
votes
2answers
160 views

Strange Behavior when making Equal Listable in Pick

While trying to make this problem more efficient I tried different methods and dabbled with making Greater and Equal ...
12
votes
2answers
187 views

How can one write a robust ListableQ function?

I would like to have a test that determines if a particular function is Listable. In the case of Symbols this is merely a matter of checking Attributes. ...
9
votes
1answer
102 views

Apply N only outside a certain function

1 + f[1] // N gives 1. + f[1.] I don't want the argument of f evaluated by N; I ...
8
votes
1answer
177 views

The Flat Attribute, Unevaluated and the Evaluation Process

To make this question easy to follow let's give some symbols a couple attributes. Attributes[f] = {Flat}; Attributes[s] = {Orderless}; Now consider the ...
12
votes
1answer
305 views

Pure function with attributes of arbitrary number of arguments: Is it possible?

Mathematica allows to define pure function, like Function[{a, b},Length[Unevaluated@a]{b}][1+2,2+3] (* ==> {0} *) Pure functions in Mathematica can take an ...
2
votes
1answer
102 views

Map and Scan ignore HoldFirst

I am trying to write a simple function that takes a list of data and outputs it to a file. I'd like the name of the file to be the same as the variable that holds the list. It seems that giving a ...
5
votes
1answer
86 views

Why is NHoldFirst not propagated to symbolic derivatives?

I encountered a nasty problem that N cannot evaluate expressions containing a symbolic Derivative of a multi-parameter function ...
5
votes
2answers
220 views

Why rule does not work if Flat attribute?

The following works: ...
8
votes
1answer
204 views

Custom attributes?

Is it possible to assign custom attributes to symbols and check them later? SetAttributes[a, b] says ...
5
votes
3answers
813 views

Define an 'inner product' with AngleBracket

I want to define my own little 'Inner Product' function satisfying properties of linearity and commutativity, and I'd like to use the "$\langle$" and "$\rangle$" symbols to output my results. For ...
13
votes
1answer
235 views

Why are the attributes of Plot changing?

In version 9, with a newly started Mathematica session, try the following code: ...
31
votes
1answer
378 views

Quickly look-up usages, options and attributes of symbols

When I'm writing code in the front-end, I find myself very often looking up the list of options of a symbol over and over again in the documentation center. In most cases you find there a list of ...
21
votes
4answers
2k views

how to differentiate formally?

I have been wrapping my head around this for a while now and I have not found a solution so far. I want to work with an arbitrary number of variables in mathematica and use some built in functions. ...
6
votes
2answers
319 views

Force integration to be linear over sum?

Is there an obvious way to force Mathematica to separately integrate the terms in a sum? According to the docs, When part of a sum cannot be integrated explicitly, the whole sum will stay ...
5
votes
1answer
226 views

Why can't I remove Orderless from Plus?

I am making some random algebra equations, and I want to have the ordering be random too, such that if my random equation generator makes x+1, the output stays ...
11
votes
2answers
126 views

Package automated way of ReadProtecting all symbols

My template for building packages has, at the end, the following expression that automatically ReadProtects all symbols defined in my ...
26
votes
2answers
839 views

Block attributes of Equal

I answered “Equating matrices (or higher order tensors) element-wise” with: ...
8
votes
1answer
238 views

DiracDelta attributes

Is there any reason why DiracDelta isn't a NumericFunction but DiracComb is? I just ate a ...
26
votes
1answer
835 views

How do you set attributes on SubValues?

SubValues, as discussed in a previous question, are declared as follows ...
14
votes
2answers
450 views

SetAttributes[f,Flat]: Why the order dependence?

I'm experiencing a strange phenomenon. Here's a (quite artificial) test case: The following definition work just fine: ...