hrfft, hrlomb, hrmem - calculate and plot heart rate power spectra
hrplot - plot heart rate time series
hrfft [ options ... ]
hrlomb [ options ... ]
hrmem [ options ... ]
hrplot [ options ... ]
The first three of these UNIX shell scripts
are intended to illustrate the use of fft(1)
, lomb(1)
, and memse(1)
by
producing heart rate power spectra using the fast Fourier transform, the
Lomb periodogram, and the maximum entropy (all poles) method (also known
as autoregressive, or AR, power spectral density estimation). All four
programs derive heart rate time series from beat annotation files. hrfft
and hrmem use tach(1)
to obtain a uniformly resampled heart rate time series
from the annotation file, which is then used as input to fft or memse,
and the spectrum thereby obtained is then plotted. hrlomb and hrplot use
ihr(1)
to obtain an irregularly sampled heart rate time series. hrplot
plots this time series directly, and hrlomb uses it as input to lomb, and
then plots the spectrum.
All four programs accept the same options:
- -a annotator
- Read annotations from the specified annotator (default: the value of the
environment variable ANNOTATOR, if set).
- -f time
- Begin at the specified time
within the annotation file (default: the value of the environment variable
START, if set, or the beginning of the file otherwise).
- -l axes
- Log-transform
the specified axes (default: use linear axes). The axes can be specified
as x, y, or xy.
- -p plot-utility
- Use the specified plot-utility to generate
the output (default: the value of the environment variable PLOT, if set,
or plt(1)
, if it exists, or plot2d(1)
otherwise).
- -r record
- Produce a heart
rate power spectrum for the specified record (default: the value of the
environment variable RECORD, if set).
- -t time
- Stop at the specified time
within the annotation file (default: the value of the environment variable
END, if set, or the end of the file otherwise).
- -T device
- Produce output
on the specified device (default: the screen). The device must be among
those supported by the plot-utility (see above).
If annotator or record are
not specified using environment variables or command-line options, these
programs obtain values from the user interactively.
Although hrfft, hrlomb,
and hrmem all produce power spectra, the units of power differ among them.
Absolute comparisons can be made only between spectra produced using the
same method, from time series of the same length.
Note that these shell
scripts can be run under MS-DOS using a suitable set of UNIX-like utilities,
such as the MKS Toolkit or the GNUish MS-DOS utilities, and under MS-Windows
using the free Cygwin package.
In addition to the variables ANNOTATOR,
END, PLOT, RECORD, and START, it may be necessary to set WFDB (see setwfdb(1)
).
fft(1)
, ihr(1)
, lomb(1)
, memse(1)
, plot2d(1)
, plt(1)
, setwfdb(1)
,
tach(1)
George B. Moody (george@mit.edu)
http://www.physionet.org/physiotools/wfdb/psd/hrfft
http://www.physionet.org/physiotools/wfdb/psd/hrlomb
http://www.physionet.org/physiotools/wfdb/psd/hrmem
http://www.physionet.org/physiotools/wfdb/psd/hrplot
Table of Contents
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