Questions on attributes of functions.

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26
votes
1answer
292 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 ...
23
votes
2answers
743 views

Block attributes of Equal

I answered “Equating matrices (or higher order tensors) element-wise” with: ...
20
votes
1answer
509 views

How do you set attributes on SubValues?

SubValues, as discussed in a previous question, are declared as follows ...
13
votes
2answers
345 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: ...
12
votes
2answers
166 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. ...
11
votes
1answer
184 views

Why are the attributes of Plot changing?

In version 9, with a newly started Mathematica session, try the following code: ...
10
votes
4answers
787 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. ...
9
votes
1answer
99 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 ...
9
votes
1answer
183 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 ...
9
votes
1answer
101 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 ...
9
votes
1answer
86 views

Why does $Failed have attribute HoldAll?

Why does $Failed have attribute HoldAll? Are there typical situations where $Failed is ...
8
votes
3answers
269 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: ...
7
votes
2answers
122 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 ...
7
votes
1answer
135 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 ...
7
votes
1answer
178 views

DiracDelta attributes

Is there any reason why DiracDelta isn't a NumericFunction but DiracComb is? I just ate a ...
6
votes
2answers
211 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 ...
6
votes
1answer
112 views

Custom attributes?

Is it possible to assign custom attributes to symbols and check them later? SetAttributes[a, b] says ...
5
votes
2answers
160 views

Why rule does not work if Flat attribute?

The following works: ...
5
votes
3answers
397 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 ...
5
votes
1answer
76 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
1answer
180 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 ...
5
votes
1answer
114 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 ...
2
votes
1answer
80 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 ...