Common Patterns
This page is intended as a list of commonly used snippets and functions that can be used in K code.
If you would like to add to this list, modify the template given in Format: Common Pattern and paste it in.
Sum[edit]
+/
Description: function to sum an array. Can be used with initial value.
Examples
+/1 2 3 4 5 +/(1 2;2 3)
Dialects: all
Deltas[edit]
-':
Description: Function to find the differences between members of an array. Comes in various flavors.
Examples:
-':1 2 3 4 /the builtin eachp prepends an array with zero before evaluation, so the output is the same size -':5 2 4 8 {y/(1_;-1_)@\:x}[6 7 8;-] /you can substitute the default eachp with your own for different behaviour, like this shakti example that just evaluates over each pair in x without prepending 0 -':6 7 8 /the difference is highlighted here
Dialects: all, syntax may vary
Rotate 90 degrees left[edit]
|+:
Description: function which rotates a matrix 90 degrees left(counterclockwise).
Example
(|+:)@3 3#!9
Dialects: all