117 views

### How to evaluate only arguments, but leave topmost expression unevaluated? [duplicate]

I want to represent expressions mostly in unevaluated form, but being able to evaluate it's subparts. For example, how to evaluate only arguments, but leave topmost expression unevaluated? For ...
61k 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 ...
2k views

### How to apply or map a list of functions to a list of data?

Say I have a group of functions: f1[a_] := a * -1; f2[a_] := a * 100; f3[a_] := a / 10.0; and some data in a list: ...
1k views

### How do you check if there are any equal arguments(even sublist) in a list?

I would like to set up a function which has to return True if at least two arguments of a given List are equal. So if I give {1,4,6,2} to the function it has to ...
1k views

### Compiling more functions that don't call MainEvaluate

I would like to use Compile with functions defined outside Compile. For example if I have the two basic functions F and G F[x_] := x + 2 G[x_] := x And I want ...
634 views

### Elegantly split a matrix into positive and negative parts?

I have a matrix $M$ of real components, and I want to split it into two matrices $M^+$ and $M^-$ of the same dimensions as $M$, where $M^+$ contains the positive components of $M$ (the remaining ...
536 views

### How can I evaluate only a single step of a recursive function?

Let's say have a simple recursive function for the Fibonacci sequence f[0] := 1 f[1] := 1 f[n_] := f[n - 1] + f[n - 2] but I want to see how it will expand in a ...
702 views

### Is it possible to define new PlotTheme?

In version 10 one can define, say, \$PlotTheme = "Scientific" Which changes the appearance of all plots. This is fantastic because on the one hand, I can have ...
582 views

### Convert head Times to List

I can convert an expression with the head of Times,for example, 12*12.5*13*13.5*14*14.5 to {12, 12.5, 13, 13.5, 14, 14.5} by ...
901 views

### How to access new colour schemes in version 10?

Many colour schemes and colour functions can be accessed using ColorData. Version 10 introduced new default colour schemes, and a new customization option using ...
468 views

### Implementing a safe ValueQ that does not evaluate its argument

Mathematica has a built-in function ValueQ. Quoting the docs, ValueQ[expr] gives True if ...
207 views

### Find all heads a function is defined on

So say I've got a function g defined as follows: g[x_Integer] := x + 1 g[s_String] := s <> "!!!" How would I write a ...
751 views

### Extract function arguments

Is there a way to extract the arguments of a function? Consider the following example: I have this sum ...