The upvalues tag has no wiki summary.
13
votes
1answer
179 views
Copying one symbol into another
I would like to know how can I completely copy one Symbol to another. When I say copy, a refer to UpValues, DownValues, ...
18
votes
3answers
548 views
Emulating R data frame getters with UpValues
What's the best way to emulate R's data frames functionality? This includes the ability to select rows and columns in a 2-dimensional table by the string identifiers positioned typically in the first ...
15
votes
3answers
509 views
Do people actually use UpValues?
I know what they are and how to define them. They have to serve some purpose - else why include them? But I never used them and all examples on this site and the docs never show a practical use of ...
15
votes
1answer
161 views
Upvalues, TagSet and UpSet, what's the difference, when should a use each?
Some of the big mysteries of Universe Mathematica for me is the application of UpValues.
I know about this question and know the very poor Mathematica documentation on that. I'm very curious to know ...
10
votes
3answers
226 views
How can I hold UpValues but evaluate other expressions?
Consider these definitions:
own = "OwnValue";
down[_] = "DownValue";
sub[_][_] = "SubValue";
N[n] = 3.14;
_[___, up, ___] ^= "UpValue";
The attribute ...
10
votes
4answers
249 views
How to use pattern matching to assign values to Subscript[f,x_]?
I want to define two subscripted functions Subscript[f,1] and Subscript[f,2]. To keep the assignments local, I would like to ...
3
votes
2answers
79 views
UpValues evaluation with Dot operator
I would like to simplify some database notation, and I'm doing some tests with UpValues for that.
For example, if I set this Upvalue fot tab1:
...
