Linked Questions

159
votes
5answers
14k views

Are you interested in purchasing David Wagner's “Power programming with Mathematica”?

I recently contacted McGraw-Hill to see if they have a mechanism in place for printing out-of-print books that are still of interest. Specifically, I asked about "Power programming with Mathematica" ...
16
votes
2answers
2k views

How does Mathematica determine that an evaluation should be terminated?

How exactly does Mathematica determine that evaluation of particular expression should be finished and the result should be returned? Here are some examples of unclear behavior which have arisen, ...
24
votes
3answers
587 views

Why x = x doesn't cause an infinite loop, but f[x_] := f[x] does?

If I execute: In[1] := x = x Out[1] = x and then I evaluate the symbol x: ...
7
votes
5answers
422 views

How to display operations on list elements

When applying some arithmetic operation on two lists, I'd like to display the actual operations between the elements of each list. For example, {1, 1} + {1, -1} ...
6
votes
2answers
630 views

Manipulating slots in a pure function

How does one manipulate the slot numbers in a pure function? Some trick with Evaluate or Hold? I'm aiming for something along ...
9
votes
1answer
535 views

Performance of Dispatch and lists of Rules

The issue outlined here seems to be no longer present in version 10, if you use a Dispatch table! This because a Dispatch table ...
9
votes
1answer
180 views

Unevaluated @ {args} versus Unevaluated /@ {args}

Working my way through Robby Villegas's lovely notes on withholding evaluation, I almost got Polish Notation on my first try. Here is my final solution, which seems to work well enough: ...
8
votes
1answer
222 views

Help me understand this behaviour of the standard evaluation procedure with `Unevaluated`

Wagner's book says that, in the Standard Evaluation Procedure, If no applicable rules where found and any of the part_i has the head Unevaluated, restore ...
1
vote
1answer
243 views

How to put a Hold on a variable so it can be set

I've got a weird problem here.... So I have a function that takes blocks of codes and them uses Map on them and passes them around and then selects and returns the one that is needed. A simplified ...
3
votes
0answers
228 views

I am missing a function like HoldPattern

Temporary message: I am planning to edit this question, making the examples less confusing and by moving the things that are confusing to a separate question For any confusion about expressions that ...