Mnemonics

Mnemonics can assist with remembering the meaning of APL glyphs where on they keyboard they are found for typing them. Both of these skills are essential for an effective APL programmer. This article currently provides examples such aide-mémoires, but will be completed in due time.



Pairing glyphs with their meaning
and  give the indices (grades) needed to sort ascending and descending respectively, and look like an ascending and descending supersonic transport, respectively.

,, and   reverse or transpose an array over a given axis. The  part of the glyphs symbolise the array, while the line component (,  , or  ) indicates the line across which the reversal/transposal is done.

is matrix divide with a  symbolising a matrix and an inscribed   for "divide".

and  are also called "by" which can be remembered as reduce by.

Pairing glyphs/functionality with their keyboard locations
Below is a US English APL keyboard layout (from Dyalog APL), annotated with short mnemonics. Some of the mnemonics are then fully explained.

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begins new APL expressions just like ` button begins the main section of the keyboard. is a modified version of, so it is Shift +.

applies a function to each 1 of the argument elements, so it is on APL + 1. looks like a Roman numeral 1, so it also lives on the 1.