# Questions tagged [placeholder]

The tag has no usage guidance.

11 questions
Filter by
Sorted by
Tagged with
38 views

### Recursive error encountered when updating rules of assignment [closed]

I'm working on a problem which requires associating a single (complex) number with a pair of binary vectors. I'm doing this by creating a set of assignments through a function I call ...
• 667
228 views

### How to implement integration by parts?

I have been trying to simplify integrand expressions using integration by parts, which schematically is given by $\theta(x)\nabla\phi(x)=-\phi(x)\nabla\theta(x)$. I think this can be done as a ...
52 views

### How to make boxes independent from those cell-formatting options?

In a cell whose LanguageCategory option is "Input", boxes will be syntax-highlighted. Is there any way to diasble such ...
• 573
1 vote
128 views

### Using # and ## in same statement to represent different levels

I am trying to write some codes to judge if each row of a matrix contains any negative numbers. For example mat = {{1, 2, 3}, {-1, 2, 3}, {0, 2, 3}}, and ...
• 1,307
1 vote
43 views

### Notebook Apply with SelectionPlaceholder leaves entire pasted structure selected

Consider the following button: ...
• 2,297
647 views

### Replace rule using a wildcard

I have a complicated expression which I want to simplify following a rule. For example, if I want to make the following replacement: A[t] - B*A[t - d1] = Y[t] ...
• 33
256 views

### How to use multiple placeholders to define a function that operates on special functions.

I am trying to understand if and how I can use multiple placeholders in order to define a function that will perform more than one operations on special functions; more accurately, sums, products, etc ...
135 views

### MatchQ failing in some cases with Hold [duplicate]

Could someone clarify why the first of these MatchQ finds a match whereas the second does not? (I'm using version 10.0, in case that matters.) ...
• 1,959
1 vote
43 views

### Place Holder or Suppressing Re-ordering

Using the for loop how can I print: file0.jpg file1.jpg file2.jpg file3.jpg file4.jpg file5.jpg file6.jpg file7.jpg file8.jpg file9.jpg The closest code I came ...
103 views

### How to use special characters in .m file?

I ran into a strange problem with a function that I want to include in a package file (.m): Cleanup[data_] := data /. (\[Placeholder] -> Missing[]) When I ...
• 599