wave - waveform analyzer, viewer, and editor
wave -r record[+record
...] [ options ... ]
wave can be used to view the specified WFDB record
or records on any display controlled by an X11 server. It includes facilities
for interactive annotation editing. The keyboard and mouse are used to control
the display interactively. First-time users should read the WAVE User’s Guide,
available at http://physionet.org/physiotools/wug/
(or, while wave is running,
choose User’s Guide from the Help panel).
If you specify more than one record,
a separate wave process is started for each record. Note that all records
to be opened must be listed in a single command-line argument following
-r, with + characters (not spaces) between the record names. See ‘Running
two or more WAVE processes’ below.
Use the left mouse button to make selections,
and the right mouse button to open menus (indicated by triangular glyphs
at the right end of some buttons). See the Guide or choose Annotation Editing
from the Help panel).
- -a annotator
- Open the specified annotation
file for the previously specified record or records.
- -dpi xx[xyy]
wave for use with a display having a resolution of xx (by yy) dots per
- -f time
- Open the record(s) beginning at the specified time.
- Use shades
of grey only, even on a color monitor.
- Read the signal files in high-resolution
mode (default: standard mode). These modes are identical for ordinary records.
For multifrequency records, the standard decimation of oversampled signals
to the frame rate is suppressed in high-resolution mode (rather, all other
signals are resampled at the highest sampling frequency).
- Use monochrome
(usually black and white) only, even on a color or greyscale monitor. The
line styles selected by the -m option may be easier to distinguish on some
greyscale monitors than the default shades of grey.
- Use overlay graphics
for maximum speed and display quality if possible. This is the usual default
if the X server supports a PseudoColor or GrayScale visual. This option
exists only to force use of overlay graphics if a different mode has been
chosen as the default.
- -s signal-list
- Initialize the signal list. By default,
the signal list includes all available signals, in numerical order.
the standard (shared) color palette, even if it is possible to modify the
palette. Using this option conserves color resources if you have other
applications that use non-standard colors, at the expense of some speed
in redrawing the display. The -S option may be used in combination with
the -g option if desired.
- Set display option x. See ‘Display Options’ below
Note that wave queries the X server to determine the display
capabilities and resolution; it is not necessary to use the -g, -m, or -S
options unless you wish to restrict wave’s use of the available capabilities.
Use the -dpi option to override the server’s default resolution if it is
incorrect and cannot be changed otherwise (see comments below under ‘Resources’).
The system on which wave runs (the ‘‘host’’ system) need not be the same as
the system to which your keyboard, mouse and display are connected (the
‘‘local’’ system), provided only that the host and local systems are on the
same network. If you wish to run wave remotely, simply log in to the host
using ssh, which normally handles display redirection automatically. If
you use some other method to log in remotely, such as rlogin (not recommended)
or telnet (not recommended), it is usually necessary to grant permission
for the host system to open windows on the local system’s display (generally,
this is accomplished using xhost on the local system; see the documentation
for your X server for details), and to set the DISPLAY environment variable
on the host system appropriately (if the local system runs UNIX, the value
of DISPLAY should be local-hostname:0.0 in most cases; again, consult your
X server documentation).
wave uses many environment variables;
they are listed in this section roughly in order of importance. Many of
them need not be set at all, since wave uses reasonable default values
in most cases. Those that are set must be set on the host system.
- The name of the X server and display you are using (see above). If you
are using wave locally, or if you are logged in via ssh, DISPLAY should
be set automatically and should not need to be changed.
- The database
path (see setwfdb(1)
). If not set, wave can find database files only in
the builtin WFDB path. If you edit annotation files and wish to reopen
them later, be sure that the current directory (in which wave writes any
edited annotation files) is the first directory in your database path.
- The WFDB calibration file (see setwfdb(1)
). If not set,
wave reads the builtin default calibration file; if this is not accessible,
wave may not scale signals other than ECGs correctly.
- The name
of the analysis menu file (see below); if not set, wave uses wavemenu
if it exists in the current directory, or $MENUDIR/wavemenu.def otherwise.
- The command interpreter used within the Analysis Commands window;
if not set, wave uses /bin/sh (the Bourne shell). Other shell-related variables,
such as PATH, are also significant when wave is running commands within
the Analysis Commands window.
- The name of the text editor to be used
for modifying the analysis menu file and the log file. If not set, wave
uses textedit (a simple editor included with the XView toolkit).
- The name of a printer to be used for paper output; if not set, wave uses
the default printer.
- The command used to print PostScript data from
the standard input; if not set, wave uses ‘lpr -P$PRINTER’.
command used to print text from the standard input; if not set, wave uses
- The name of a file that contains custom annotation
definitions (see ‘Resources’, below, for details). If not set, wave uses
standard annotation definitions only.
The environment variables below are
not needed unless the wave binary distribution, or XView, has been installed
in non-standard directories:
- The path for XView spot help; if
not set, wave initializes it to /usr/lib/help. wave’s own spot help is in
$HELPDIR/wave, which is appended to the end of HELPPATH by wave.
- The directory in which wave’s help directory is located; if not set, wave
- The name of the directory that contains the
default analysis menu file; if not set, wave uses /usr/local/lib.
- The name of the directory in which system-wide default X11 resource files
are kept; if not set, wave uses /usr/lib/X11/app-defaults. XUSERFILESEARCHPATH,
XAPPLRESDIR, and XENVIRONMENT are also used, together with HOME and USER,
to locate resource files (see X(1)
You can control many aspects
of wave’s appearance and behavior by setting its resources. If you are not
familiar with this concept, refer to an introductory book on using the
X Window System, such as Darwin, Quercia, and O’Reilly’s X User’s Guide: Open
Look Edition (see the link below). Since wave is built using the XView toolkit,
all of the resources listed in xview(7)
can be used with wave. In addition,
the following wave-specific resources may also be set:
Initial values for the settings controlled
from wave’s View window can be specified using either X resources or command-line
options. Once suitable settings have been selected, use the ‘Save as new
defaults’ button in wave’s View window to record them in your .Xdefaults file.
In this section, the X resource name is specified first, and the command-line
- This resource specifies if wave is allowed to render dotted lines. wave
normally draws annotation marker bars as dotted lines, and may use dotted
lines for other display elements on black-and-white displays for clarity.
Some X servers do not properly render dotted lines, however; if you observe
irregular or missing annotation marker bars, change the value of this resource
from True to False.
- This resource specifies the name of a file
that contains a table of annotation definitions. The environment variable
ANNTAB can also be used to specify this filename; the resource overrides
the environment variable if both are set. The file contains one-line entries
of the form
15 % Funny looking beat
in which the first field specifies the (numeric) annotation code in the
range between 1 and ACMAX inclusive (see /usr/include/wfdb/ecgcodes.h for
a list of predefined codes and for the definition of ACMAX); the second
field (‘%’ in the example) is a mnemonic (used in annotation display and
entry), and the remainder of the entry is a description of the intended
use of the annotation code (which appears next to the mnemonic in the ‘Type’
field and menu of ‘Annotation Template’ windows). Lines in the annotation
table that begin with ‘#’ are treated as comments and ignored. It is not
necessary to specify an annotation table when editing an existing annotation
file unless previously undefined annotation types are to be added to it
during the editing process, although it is generally harmless to do so.
- This resource specifies the display resolution in dots per inch
in the form MMxNN, where MM is the horizontal resolution and NN is the
vertical resolution. Normally, the resolution is known to the X server,
and it is unnecessary to specify this resource. If your X server is misinformed,
wave’s calibrated display scales will be incorrect; the best solution is
to specify the resolution using a server option such as the -dpi option
supported by MIT’s X11 servers, since this will solve problems common to
any other applications that require calibrated scales as well. Not all
X11 servers support such an option, so this resource is available as a
work-around. The command-line option -dpi overrides the resource if both
are specified. (If you don’t know the resolution, use xdpyinfo(1)
what your X server thinks it is. Then run wave, enable the grid display,
and measure the grid squares with a ruler. If they are larger than 5 mm,
the number of dots per inch returned by xdpyinfo is too large; adjust
the Wave.Dpi resource proportionally, and repeat the process until the grid
squares measure 5 mm in each direction.)
- This resource
specifies the graphics mode used by wave; it can be overridden using the
-g, -m, -O, or -S options. The legal values are 1 (monochrome mode), 2 (overlay
greyscale mode), 4 (shared color mode), 6 (shared grey mode), and 8 (overlay
- These resources specify
the colors to be used on greyscale or color displays. The ‘Color.*’ resources
are used only if the display is color-capable and neither greyscale nor
monochrome mode has been specified. The defaults are:
- In monochrome mode, the background is normally white, and all other display
elements are normally black. The reverse can be obtained by setting this
resource to black. (There is at least one server for which this fails.)
- These resources specify the
colors to be used in the Scope window on greyscale or color displays. The
Foreground color is used for the waveform and the time display; by default,
it matches the color used for signals in the signal window (see the previous
item). Some X servers do not allow the background color of the Scope window
to be set, because of the color map animation and stippled erasing techniques
- This resource can be used to invert the foreground
and background of the Scope window when WAVE is running in monochrome mode.
This does not work for all X servers.
- These resources specify the preferred dimensions (in millimeters) for the
signal window. The defaults are 120 and 250 respectively.
- This resource specifies the font used to display annotations and time marks
in the signal window. The default is fixed.
- This resource
specifies the name of the text editor invoked by wave to permit you to
edit wave’s log and analysis menu files. The default is textedit (the OpenLook
visual editor). You may override this resource by using the environment
variable EDITOR, which is also used by many other UNIX applications that
By default, all of the display options in the first group
are off (False); set any of these X resources to True to enable these options,
or use the command-line options to do so.
- Wave.View.Subtype (-Vs)
- Display annotation
- Wave.View.Chan (-Vc)
- Display annotation chan fields.
- Display annotation num fields.
- Wave.View.Aux (-Va)
- Display annotation
- Wave.View.Markers (-Vm)
- Display annotation marker bars.
- Display signal names along the left edge of the signal window.
- Display baselines for any DC-coupled signals, and label the zero levels
and the units along the right edge of the signal window.
- Wave.View.Level (-Vl)
- While the pointer is in the signal window and any mouse button is depressed,
track the intersections of the marker bar with the signals and draw horizontal
marker bars across the signal window at the levels of these intersections.
The remaining resources and command-line display options correspond to the
menu buttons in wave’s View window. The value of each resource, or the numeric
argument that immediately follows the command-line option, should match
the position of the desired menu choice, where the top item on each menu
is in position 0, the one below it is in position 1, etc. For example,
to set the initial amplitude scale to 5 mm/mV (the item at position 2 in
the ‘Amplitude scale’ menu), add -Vv 2 to the command line, or Wave.View.AmplitudeScale:2
to the X11 resource database.
- Wave.View.TimeScale (-Vt)
- Set the time scale
(0: 50 mm/min; 1: 125 mm/min; 2: 250 mm/min; 3: 500 mm/min; 4: 12.5 mm/sec;
5: 25 mm/sec (default); 6: 50 mm/sec; 7: 125 mm/sec; 8: 250 mm/sec).
- Set the amplitude scale (0: 1 mm/mV; 1: 2.5 mm/mV; 2: 5 mm/mV; 3: 10
mm/mV (default); 4: 20 mm/mV; 5: 40 mm/mV; 6: 100 mm/mV).
- Set the choice on the ‘Draw’ menu (0: all signals (default); 1: listed
- Wave.View.AnnotationMode (-VA)
- Set the choice on the ‘Show annotations’
menu (0: centered (default); 1: attached to signals; 2: as a signal).
- Set the choice on the ‘Time display’ menu (0: elapsed (default); 1:
absolute; 2: in sample intervals).
- Wave.View.GridMode (-VG)
- Set the choice
on the ‘Grid’ menu (0: none; 1: 0.2 s; 2: 0.5 mV; 3: 0.2s x 0.5 mV (default)).
In addition to the usual ways of setting X resources, it is possible to
set any of those listed above, as well as any of the generic XView resources,
by using the -xrm or -default options on the command line when starting wave.
For example, you can set the background color of the signal window using
a command such as
wave -r 100s -xrm Wave.SignalWindow.Color.Background:lightblue
By specifying two or more record names,
separated by ‘+’ characters, in the command-line argument that follows ‘-r’ (see
above), you may open separate WAVE signal windows (processes) for each
record. These processes are almost completely independent: from any signal
window, you may navigate within the record, change display settings, edit
annotations, run external analysis programs, quit the process, etc., without
affecting any other signal windows.
For example, you may open two signal
windows for the same record by:
wave -r 100+100 -a atr
You can now move about the record freely in either window. This facility
makes it easy to compare different segments of the record. Note that whenever
two or more windows are displaying the same set of annotations, as in this
case, only one should be editing the annotations at any given time.
window associated with the last record named on the command line has a
special status: it is designated the master signal window, and an extra
button (labelled ‘Sync’) appears at the top of this window. Clicking on this
button causes all of the other signal windows to be redrawn so that the
times shown in their lower left corners match that in the master signal
window. (Note, however, that if you have quit a signal window from the
middle of the list, any signal windows from earlier in the list will no
longer respond to sync requests.)
By default, all command-line arguments
apply to all signal windows. You may specify an argument that is to apply
to only one signal window, however, by prefixing the argument with ‘+n/’,
where n is the signal window number. (The first signal window, corresponding
to the first record named on the command line, is signal window number
0; the next is number 1, etc.)
This facility has many applications. For
example, you may wish to open two copies of the same record, with two different
wave -r 100+100 -a +0/atr +1/qrs
In this case, record 100 is opened in two windows, with annotator ‘atr’ in
window 0 and annotator ‘qrs’ in window 1. (The ‘-a’ option applies to both windows
since it does not have a ‘+n/’ prefix.)
As another example, you may wish to
discuss a record with colleagues at other locations:
wave -r 200+200+200 -a qrs +0/-display +0/atlantic.bigu.edu:0 \
Here, record 200 is opened in three windows. Window 0 is opened on display
0 of atlantic.bigu.edu, window 1 on display 0 of pacific.widget.com, and window
2 (the master window) on the local display. (For this to work, your colleagues
must first allow your computer to open windows on their displays, typically
using xhost. See xview(7)
for information about the -display option. Notice
that the ‘+n/’ prefix must be attached to both the ‘-display’ option and to
its argument in order to apply both of these arguments to the same signal
window.) Your colleagues can freely move about the record, but you can direct
the discussion at any time by using the Sync button in your signal window.
In a case such as this one, anyone can enable editing; you should do so
only after making sure that no one else has. Once you have saved your work
(by selecting ‘Save’ from the File menu), your changes become visible to
your colleagues if they reload the annotations (by clicking on ‘Reload’ from
the Load window).
As a final example, the MIMIC Database includes both high-resolution
waveform records and medium-resolution (roughly 1 sample per second) computed
measurement records. You may view both of these at the same time using
a command such as:
wave -r 237+237n -a all
Typically, you will wish to view the high-resolution and low-resolution data
at different time scales. Although wave attempts to choose reasonable defaults,
you can adjust the scales independently if you wish:
wave -r 237+237n -a all +1/-Vt +1/2
If you use wavescript or wave-remote to control the master signal window
(this happens by default unless you use the -pid option of these programs
to control a different signal window), the other signal windows are kept
synchronized with the master window.
Note that you cannot increase the number
of signal windows in a group once you have started a wave process group,
although you can run more than one process group at a time if you wish.
wave uses a simple menu file to allow you to set up analysis
options. Each line in the file corresponds to a button in the Analyze window
(except for empty lines and lines that begin with ‘#’, which are ignored).
Within each line, the syntax is label<tab>action, where <tab> is one or more
tab characters. The label field is used to identify a command button in
the Analyze window, and the action field is any command acceptable to your
shell. button-label and action may include spaces if needed; if necessary,
a ‘\’ may be used at the end of a line to indicate that it is continued on
the next line. Before the command is executed, wave replaces certain tokens
with appropriate strings; these include:
- The name of the current
- The name of the current input annotator.
- The currently
selected ‘start analysis’ time.
- The currently selected ‘end analysis’ time.
- The time interval between $END and $START.
- The time corresponding
to the left edge of the signal window.
- The time corresponding to
the right edge of the signal window.
- The time interval between $RIGHT
- The currently selected signal number (as shown in the
- The current signal list (as shown in the Analyze
- The name of the current log file (as shown in the Log window).
- The WFDB path (from the Load window).
- The name of the WFDB
calibration file (from the Load window).
- The time scale, in mm/sec.
- The amplitude scale, in mm/mV.
- The annotation display
mode (0: annotations displayed in center, no marker bars; 1: annotations
displayed in center, long marker bars; 2: annotations attached to signals,
no bars; 3: annotations attached to signals, short bars; 4: annotations
displayed as a signal, no bars; 5: annotations displayed as a signal, long
- The command for printing PostScript data from the standard
input, as specified in the Print Setup window.
- The command for
printing text from the standard input, as specified in the Print Setup
- The URL specified by the most recently selected link.
tokens that begin with ‘$’ are passed to the shell unchanged.
menu file includes the following lines (among others):
| Mark QRS complexes||sqrs -r $RECORD -f $START -t $END -s $SIGNAL|
-r $RECORD -f $START -t $END -s $SIGNALS|
| Extract segment||snip -i $RECORD -f $START
-t $END -n n_$RECORD \ |
| -a $ANNOTATOR|
| List annotations||rdann -r $RECORD -a $ANNOTATOR
-f $START -t $END|
| List samples||rdsamp -r $RECORD -f $START -t $END -s $SIGNALS|
Print chart||echo $RECORD $START-$END | \ |
| pschart -a $ANNOTATOR -g -l -R -s $SIGNALS
- | $PSPRINT|
| Print full disclosure||echo $RECORD $START-$END | \ |
| psfd -a $ANNOTATOR
-g -l -R -s $SIGNALS - | $PSPRINT|
Whenever the pointer is in
the signal window, the normal arrow pointer is replaced by a crosshair
pointer. At these times, the numeric keypad and several of the function
keys may be used for many annotation editing and display operations, and
the normal alphanumeric and punctuation keys can be used to select single-character
annotation mnemonics (displayed in the Annotation Template window). ‘Num
Lock’ must be off if you wish to use the keypad for editing operations.
Some of the function and numeric keypad commands work on Sun keyboards
only; in these cases, alternate keyboard commands for use with PC and
other keyboards are shown in parentheses. Most of these alternate commands
also work on Sun keyboards.
- <Help> (<F1>)
- Open XView spot help for the item
under the pointer. (Unlike most of the other keyboard commands, this command
is available at any time, not only when the pointer is in the signal window.)
- <left arrow>
- Select the annotation to the left of the pointer. (Click left
to do this using the mouse. These actions also work when the pointer is
in the scope window.)
- <right arrow>
- Select the annotation to the right of
the pointer. (Click right to do this using the mouse. These actions also
work when the pointer is in the scope window.)
- <up arrow> Move the selected
annotation up one signal (i.e.,
- decrement its chan field). This command works
in multi-edit mode only (enter multi-edit mode by choosing ‘attached to signals’
from the ‘Show annotations’ menu in wave’s View window).
- <down arrow>
- Move the
selected annotation down one signal (i.e., increment its chan field). This
command works in multi-edit mode only.
- keypad <5> (<F2>)
- Insert an annotation
at the current position of the pointer. (Click the middle button to do
this using the mouse. Annotation editing must be enabled for this action
to be successful.)
- keypad <=> (<F3>)
- Move the pointer toward the left.
- Move the pointer toward the right.
- <Copy> (<F6>)
- Copy the selected annotation
to the Annotation Template.
- <Find> (<F9>)
- Search forward.
- <ctrl><Find> (<ctrl><F9>)
- <End> (<shift><F9>)
- Advance to the end of the record.
- <Home> (<ctrl><shift><F9>)
- Move to the beginning of the record.
- <PgDn> (<F10>)
- Advance half a screen.
- Advance a full screen.
- <PgUp> (<shift><F10>)
- Move back half a screen.
- <ctrl><PgUp> (<ctrl><shift><F10>)
- Move back a full screen.
- <Enter> (<Return>)
- (Only if
a link annotation has been selected.) Show the external data specified
by the link using a Web browser; start the Web browser first if necessary.
Under SunOS, once you have opened the Analyze window or have selected
Print from the File menu, do not attempt to suspend wave (for example,
by typing control-Z in the controlling terminal window). Under these circumstances,
wave may exit immediately (without quit confirmation) and any unsaved edits
may be lost. This problem is the result of a bug in the XView termsw package
used for the Analysis Commands window. To avoid this bug, always run wave
in the background under SunOS. The Linux, Mac OS X, MS Windows, and Solaris
2.x versions of the XView library do not have this bug.
If wave opens with
an empty signal window, this may mean that the X server’s backing store
is disabled. wave versions 6.8 and later incorporate a workaround that avoids
this problem. If you must use an earlier version of wave, enable backing
store and restart the X server. (Using the X servers from the x.org or XFree86
projects, backing store can be enabled by inserting the line ‘Option "backingstore"’
in the ‘Device’ section(s) of the xorg.conf or XF86Config-4 file. If your X
server is normally started by a display manager such as xdm, close all
windows and restart the server with <ctrl><alt><backspace>. Otherwise, log out,
log in, and restart the X server manually if necessary.)
If this doesn’t
solve the problem, use any of wave’s navigation controls, or resize the
signal window, to make the signals visible. On some 24-bit displays, this
problem may be the result of an X server bug, and these methods will work
around the problem. On some of these displays, text in the signal window
may be invisible using overlay graphics mode; if this happens, use the
No more than one piped record (see the WFDB Programmer’s Guide)
can be viewed in a single invocation of wave. If the signal file is a pipe,
it is possible only to search forward through it (although wave caches
several of the most recently displayed windows, which can be reviewed in
any case). Using the ‘>’ button to move by half a frame does not work properly
with piped input, nor does changing the display scales, since these actions
require rereading the signals.
There appears to be a subtle incompatibility
between XView-based applications such as wave and at least some X servers.
The symptom of this problem is that wave’s View panel may be blank, and
many warning messages from the notifier may appear in the controlling terminal
window. This problem appears to occur only when all of the following are
true: the X server is running on a multi-head display with Xinerama enabled,
the user does not have root privileges, a .Xdefaults file exists, and wave
or another XView application has run at least once since the X server was
A more serious incompatibility (which may be related to the subtle
incompatibility noted above) appeared with the release in 2009 of the X.org
version 1.6.3 X server, which freezes when any application that uses the
XView library (such as wave) ’grabs’ the mouse pointer. By default, XView
applications do so in response to a left button click on any XView control.
’Grabs’ can be disabled, and this behavior avoided, by using the -Wfsdb option
available in wave and in other XView applications. In wave version 6.10 and
later versions, the default behavior of XView has been changed to disable
’grabs’, and this problem does not occur.
WAVE User’s Guide (http://www.physionet.org/physiotools/wug/)
X Window System User’s Guide: Open Look Edition (http://www.oreilly.com/openbook/openlook/)
wave currently runs under FreeBSD, GNU/Linux, Mac OS X, MS-Windows
with Cygwin/X, Solaris, and SunOS. It should be easily portable to any
POSIX-compliant OS that can support X11 and XView. If you would like to use
wave on a system other than those listed above, you will need to port XView
to your system first (or purchase a commercial port if one is available).
Sources for XView are available from PhysioNet (www.physionet.org, where
the sources for wave itself are also available), www.ibiblio.org, and their
mirrors. We cannot offer assistance in porting XView; if you wish to try
this, you are on your own. If you successfully port the cmdtool terminal
emulator application included in the XView sources, we will assist you
in porting wave (this is much simpler than the XView port).
B. Moody (email@example.com)
Table of Contents
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Updated 28 May 2015