# Tag Info

### How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc

You can also use Refine with Element : ...
• 7,225

### Preventing Superscript from being interpreted as Power when using Ctrl+^ shortcut?

Superscript is not interpreted as Power: Presumably you are referring to what happens when you enter a power in superscript ...
• 265k

### Best practice of passing a large number of parameters to functions

Basic proposal There are a number of options and their attractiveness will depend on the scenario for their use, therefore it is difficult to make any broad recommendations of best practice. I will ...
• 265k
Accepted

### How can I make assignments persist across sessions?

If you wrap your definitions in Once then their results will be remembered across sessions: ...
• 38.1k

Accepted

### Confusing behavior when passing a variable vs. inlining a function call

Mathematica is an expression rewriting language. When it evaluates: q[[RandomInteger[{1, 2}]]] += 1 It first rewrites it as: ...
• 13.6k
Accepted

### When is a symbol a Symbol? Is there an easy Mathematica way to test if an object is a symbol sort of like a SymbolQ?

I'd probably use x_Symbol in a function argument to control evaluation. Otherwise, one might do the following (thanks to @Leonid for pointing out an oversight). If ...
• 222k
Accepted

### very simple but unexpected aspect of Function[ ]

The issue is that to SetDelayed1 (:=), Function is just a normal head. For your third ...
• 27.1k
Accepted

### How to make Mathematica variables declarative instead of just-in-time?

Edit: method extended for multiple contexts and unlocking mehtod added. Let's protect whatever is a new symbol. In old answer I've manually excluded symbols matching ...
• 133k
Accepted

### Attempts at backwards compatibility

If you just want backwards compatibility, there is no need to create any symbols in the System context. It seems like a bad idea to do such things. A package should create symbols only within its ...
• 228k

### Finding a variable name given its numerical value

a = 1; Select[Names["Global*"], Symbol[#] == 1 &] {"a"} Notice it may not be robust if you have a habit of writing ...
• 133k
Accepted

### When is a symbol a Symbol? Is there an easy Mathematica way to test if an object is a symbol sort of like a SymbolQ?

How about: SymbolQ[_Symbol] = True SymbolQ[_] = False ?
• 13.6k
Accepted

### Find all heads a function is defined on

If your definitions are exactly like you show, every time, you can use belisarius's method, slightly refined: ...
• 265k
Accepted

### How can I define variables that follow a naming pattern?

Here's a pretty natural way, I think, that almost matches your variable names. ...
• 21.7k

### Cannot get determinant of matrix

Mathematica does not distinguish between row and column vectors (...
• 126k

### How can I make assignments persist across sessions?

Like in all other systems I am familiar with, variable and function definitions exist in memory (RAM) only and do not persist across sessions. If you want a definition to persist, you must save it ...
• 228k