Emacs's Command Frequency (Old)

2010-02-13. This file is obsolete. For the latest version, please see: Emacs's Command Frequency.

This page lists emacs's commands in the order of their frequency of use.

In emacs, each key press actually calls a command. (e.g. pressing “a” actually calls the command self-insert-command. Pressing Ctrl+f calls the command forward-char . Pressing Alt+x calls execute-extended-command . Pressing the → calls forward-char .)

The motive of this study, is in designing a ErgoEmacs Keybinding. I needed to know which command are actually more frequently used, in order to give it a easier-to-press keybinding.

Preliminary

The following frequency list is based 3 users. Xah Lee (me), Marc Shapiro, Rick Bielawski (aka rgb). The total count of all command calls is 203118. The following is a break down of each's data contribution:

Name       Command calls    Percentage
-------------------------------------------
Rick            93 534          46%
Xah             82 090          40%
Marc            27 494          13%
-------------------------------------------
total          203 118         100%

The total count of self-insert-command calls is 65 496. The following is a break down by that command.

Name         number of         Percentage
             self-insert-
             command call
-------------------------------------------
Xah             29 758          45%
Marc            20 026          31%
Rick            15 712          24%
-------------------------------------------
total           65 496         100%

Following is a table showing the proportion of each person's use of data-entry commands and non-data-entry commands. “data-entry” commands are the commands: “self-insert-command” (invoked by pressing a single letter/number/symbol key), “newline” (invoked by Enter/Return key). Basically, data-entry commands are just typing. All other commands are considered “non-data-entry”.

Name        Percentage of non-data-entry commands
---------------------------
Rick            83%
Xah Lee         63%
Marc Shapiro    26%

A higher percentage of non-data-entry commands probably means that the person is doing a lot editing, as opposed to writing. (if a person uses emacs for email or IRC chat, she's likely to have high percentage of data-entry commands.)

Commands that are executed by the same key are grouped together. For example, the commands “delete-backward-char”, “backward-delete-char-untabify”, “python-backspace”, “cperl-electric-backspace” are all just the “Backspace” key.

The following is the complete list of commands that are merged.

command names                 merged into this glyph
---------------------------------------------
next-line                     ↓
dired-next-line               ↓
next-history-element          ↓

previous-line                 ↑
dired-previous-line           ↑
previous-history-element      ↑

delete-backward-char          ⌫
backward-delete-char-untabify ⌫
python-backspace              ⌫
cperl-electric-backspace      ⌫

scroll-up                     ▼
cua-scroll-up                 ▼

scroll-down                   ▲
cua-scroll-down               ▲

isearch-forward                isearch-→
isearch-repeat-forward         isearch-→

isearch-backward               isearch-←
isearch-repeat-backward        isearch-←

For clarity, some commands are replaced by a glyph. Here's the complete list:

backward-char           ←
forward-char            →
backward-word           ←w
forward-word            →w
backward-sentence       ←s
forward-sentence        →s
backward-paragraph       ↑¶
forward-paragraph        ↓¶

move-beginning-of-line  |←
move-end-of-line         →|
beginning-of-buffer     |◀
end-of-buffer           ▶|

delete-char            ⌦
kill-word              ⌦w
backward-kill-word     ⌫w
kill-line              ⌦l
kill-sentence          ⌦s
kill-ring-save         copy
kill-region            ✂

Command Frequency Table

Total number of command calls: 203118

Percent of non-data-entry command calls: 67%

How The Report Is Compiled

Here we describe how the report is generated. Each person, uses this emacs code: command-frequency.el, which will accumulate a keyed-list of all command the user calls in emacs, with key being the command name and value being its count. After some time, the user calls command-frequency-display which will write the stat into a buffer, then the user save it to file.

The raw data files used in this report are here: command-frequency_old.tgz

A Python program command-frequency_v1.1.py, is used to parse these raw data files. The program aggregate all user's raw data, then groups some commands together as described in this report, and replace some command names by a corresponding glyph, and print them in HTML table format. Commands used less than 0.1% of total non-data-entry commands are not displayed.

When this report is written, the command logging program “command-frequency.el” used “this-command” variable to record what command is being called. The “this-command” lumps together backward-kill-word, kill-word, kill-line, kill-region, all into just kill-region. (see: Command Loop Info (ELISP Manual) ) This problem is fixed in the current version of the “command-frequency.el”. (it now uses real-last-command variable to log commands)

Subsequent stat using Xah Lee's stat shows that, the lumped kill commands have this frequentcy distribution:

The above distribution is retrofitted into the report.

If you like to participate in this research, please download command-frequency.el and send me the output. I will incorporate your data into the next report update. Thank you.

Thanks to Ryan Yeske for the inital version of command-frequency.el. Thanks to Michal Nazarewicz writing it into a full featured minor mode. Thanks to David Capello for improving the code. Thanks to Katsumi Yamaoka for pointing out the problem of “this-command”. Thanks to Stefan Guath for pointing out “real-last-command”. Thanks to Marc Shapiro and Rick Bielawski for providing me their data.

2009-01-23 Addendum: My own (Xah Lee) command usage stat for 5 months: command-frequency_xah.txt.