Linked Questions

284
votes
12answers
51k views

Where can I find examples of good Mathematica programming practice?

I consider myself a pretty good Mathematica programmer, but I'm always looking out for ways to either improve my way of doing things in Mathematica, or to see if there's something nifty that I haven't ...
40
votes
2answers
1k views

Head and everything except Head?

I have been working on picking expressions apart using Head and Part and encountered a little mystery. Consider the canonical ...
6
votes
3answers
2k views

Assigning values to a list of variable names

As part of a calculation I need to do something like this Evaluate[{aaa, bbb, ccc}[[ index]]] = {1, 2, 3, 4, 5} so if index is ...
6
votes
2answers
151 views

How to Clear variables represented as a list of strings?

Say I have a string list called fullpara fullpara={"width", "long", "line", "distance"} And there are corresponding variables ...
2
votes
3answers
178 views

How to create a writable and clearable symbol? [duplicate]

I'm trying to create several symbols and assign values to them. Here's what currently appears to work: Evaluate[Symbol["fdds" <> ToString[10]]] = 1 But ...
3
votes
3answers
107 views

Using a variable to tell Mathematica which existing variable to manipulate

I have an estimation routine I have coded up, I want now to do some tests on it where I pick a particular parameter and run the estimation for differing values of that parameter. What I want is to be ...
4
votes
2answers
180 views

why set values in this way doesn't work?

question is as follows define a list ttt={1,2}; and if I set values in this way {ttt[[1]],ttt[[2]]}={3,4} then the value ...
1
vote
2answers
151 views

Why does Evaluate[a[[1]]]=0 assign a value to a variable while a[[1]]=0 doesn't?

I'm trying to do a small page counter with Mathematica, for leting me know about my reading progress on some books. I'm stuck on a problem: ...
1
vote
1answer
133 views

direct assignment to the element in a Table

I have already asked a related question here why set values in this way doesn't work? But I think I have to write the question which I encountered explicitly? ...
1
vote
2answers
72 views

How do I use a passed-in symbol as a tag to define UpValues?

ClearAll@foo; foo[tag_] := ( tag /: tag[i_] := tag[[i]] ); a = {7, 8, 9}; foo[a]; a[2] I wanted the above to output 8, ...
0
votes
1answer
105 views

A problem with set values

The following code is just an example to clearly explain my problem. Assume that : ...
-1
votes
2answers
71 views

How to fix the “Module” function, for implicit funcitons? [closed]

I wanted to make a function which gives the frequencies of a number in a specific list, when I came accros this problem. This is what I tried: ...
3
votes
0answers
138 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 ...