Pure Data Keyword Reference

A reference for objects and commands used in Pd patches.

Basic Operations

Operation	Shortcut
Place an object	Cmd (Ctrl) + 1
Place a message	Cmd (Ctrl) + 2
Place a number box	Cmd (Ctrl) + 3
Place a symbol box	Cmd (Ctrl) + 4
Place a comment	Cmd (Ctrl) + 5
Toggle edit/run mode	Cmd (Ctrl) + E
Zoom in	Cmd (Ctrl) + Shift + ;
Temporary run mode	Hold Cmd (Ctrl)
Help browser	Cmd (Ctrl) + B
Place a bang	Shift + Cmd (Ctrl) + B
Place a toggle	Shift + Cmd (Ctrl) + T
Place a horizontal slider	Shift + Cmd (Ctrl) + J
Place an array	Cmd + Shift + A
Delete an object	Select → Backspace
Object help	Right-click → Help

Sound Generation

Object	Description	Usage
osc~	Sine wave oscillator	[osc~ frequency]
phasor~	Sawtooth wave	[phasor~ frequency]
noise~	White noise	[noise~]
else/tri~	Triangle wave (ELSE library)	[else/tri~ frequency]
else/square~	Square wave (ELSE library)	[else/square~ frequency]

Audio I/O

Object	Description	Usage
output~	Audio output	Set volume with level value message
else/out~	Audio output (with DSP on/off switch)	ELSE library
dac~	Digital-to-analog converter (audio output)	[dac~ channel_numbers]
adc~	Analog-to-digital converter (audio input)	[adc~]

Volume & Envelopes

Object	Description	Usage
*~	Signal multiplication (used for volume control)	signal x signal or number
line~	Automatic value change (signal)	[target_value time(ms)] message
vline~	Continuous value change	[value1 time1, value2 time2 start_time, ...]
delay	Output a bang after a delay	[delay time(ms)]
else/asr~	ASR envelope	ELSE library
else/adsr~	ADSR envelope	ELSE library
else/envgen~	Custom envelope generator	[else/envgen~ -curve]

Arithmetic

Object	Description	Usage
+, -, *, /	Basic arithmetic (values)	[+ number]
expr	Expression evaluation	[expr $f1 * 2 + $f2]
mtof	MIDI note → frequency (Hz)	Middle C = 60

Data Routing

Object	Description	Usage
s (send)	Send a value	[s destination_name]
r (receive)	Receive a value	[r destination_name]
sel	Route by matching values	[sel value1 value2 ...]
route	Route by first element	[route address1 address2]
change	Output only when the value changes	[change]
t (trigger)	Send values right-to-left	[t f b] (f: float, b: bang, a: symbol)

Filters

Object	Description	Usage
lop~	Low-pass filter	[lop~ cutoff_frequency]
hip~	High-pass filter	[hip~ cutoff_frequency]
bp~	Band-pass filter	Center: cutoff, Right inlet: Q value

Filter Notes

• Filters other than lop~ cannot accept vline~ output directly on their right inlet
• Pay attention to the difference between value (thin) and signal (thick) lines

Delay

Object	Description	Usage
delwrite~	Write to a delay buffer	[delwrite~ $0-delay buffer_size(ms)]
delread~	Read from a delay buffer	[delread~ $0-delay delay_time(ms)]
cyclone/delay~	Delay (cyclone library)	cyclone library

About $0

$0 is a unique ID number assigned to each Pd patch. Using it in buffer names like $0-delay prevents name collisions when duplicating patches.

Signal-Value Conversion

Object	Description	Usage
sig~	Value → signal conversion	[sig~]
snapshot~	Signal → value conversion	Outputs the signal value when it receives a bang
metro	Periodic bang output	[metro period(ms)]
else/s2f~	Signal → value (automatic)	Continuous output without needing bangs
else/f2s~	Value → signal	ELSE library
else/numbox~	Display signal values	Display GUI

DSP Must Be On

Signal-related objects will not work unless DSP is turned on. Enable it via the checkbox in the top-right of the console, or raise the volume on output~.

Audio File Processing

Object	Description	Usage
else/play.file~	Audio file playback	[else/play.file~ filename loop(0/1) autoplay(0/1)]
else/stretch.shift~	Pitch shift / time stretch	Pitch: 0=original, 1200=1 octave; Tempo: 100=original
else/xselect~	Crossfade selection	[else/xselect~ num_channels fade_time(ms)]
else/xfade~	Crossfade	ELSE library
else/rec.file~	Record to file	[else/rec.file~ filename]
soundfiler	Load WAV data into an array	read filename array_name
tabplay~	Play audio from an array	[tabplay~ array_name]

Automated Playback

Object	Description	Usage
text define	Define text data	[text define -k filename]
text sequence	Sequential text output	auto: automatic, bang: one step, line 0: go to start
else/drum.seq	Rhythm machine GUI	[else/drum.seq rows columns]
else/tempo	BPM tempo output	[else/tempo BPM -mul multiplier]
random	Random integer output	[random max_value]

micro:bit Integration (OSC)

Object	Description	Usage
else/osc.receive	Receive OSC data	[else/osc.receive port_number]
else/osc.route	Route by OSC address	[else/osc.route /address1 /address2]
cyclone/scale	Value mapping	[scale input_min input_max output_min output_max]
clip	Value clipping	[clip lower_limit upper_limit]
else/smooth~	Smoothing (signal)	ELSE library

GUI

Object	Description	Operation
bang	Trigger output	Click to send
toggle	0/1 switch	Click to toggle
Number box	Numeric display/input	Drag to change value
Horizontal slider	Continuous value input	Right-click → Properties to set upper/lower limits

Miscellaneous

Object	Description	Usage
print	Print to console	For debugging
comport	Serial communication	[comport device_number baud_rate]
pd subpatch_name	Subpatch	Create a subpatch within a patch
clone patch_name	Clone a patch	Generate multiple copies of the same patch

Useful Facts

Weber-Fechner Law

Human subjective perception of intensity is proportional to the logarithm of the physical stimulus. To make volume changes feel natural, raise the volume value to the 4th power.

Structure of Musical Tones

Instrument-like sounds consist of a fundamental frequency (the lowest tone) combined with harmonics at integer multiples. By combining multiple osc~ objects, you can create a variety of timbres (additive synthesis).