#!/usr/bin/python
#
# File: example10.py I. Henry March 30 2005
#
# Python translation of example10.c from the WFDB Programmer's Guide
#
# Copyright (C) 2005 Isaac C. Henry (ihenry@physionet.org)
import wfdb, sys
def main(argv):
time = maxslope = nslope = scmin = 0
a = wfdb.WFDB_Anninfo()
annot = wfdb.WFDB_Annotation()
if len(argv) < 2:
print "usage:", argv[0], "record [threshold]"
sys.exit(1)
a.name = "qrs"
a.stat = wfdb.WFDB_WRITE
nsig = wfdb.isigopen(argv[1], None, 0)
if nsig < 1: sys.exit(2)
s = wfdb.WFDB_SiginfoArray(nsig)
v = wfdb.WFDB_SampleArray(nsig)
if wfdb.wfdbinit(argv[1], a, 1, s.cast(), nsig) != nsig: sys.exit(2)
if wfdb.sampfreq(None) < 240. or wfdb.sampfreq(None) > 260.:
wfdb.setifreq(250.)
if len(argv) > 2: scmin = wfdb.muvadu(0, argv[2])
if scmin < 1: scmin = wfdb.muvadu(0, 1000)
slopecrit = scmax = 10 * scmin
ms160 = wfdb.strtim("0.16")
ms200 = wfdb.strtim("0.2")
s2 = wfdb.strtim("2")
annot.subtyp = annot.chan = annot.num = 0
annot.aux = None
wfdb.getvec(v.cast())
t9 = t8 = t7 = t6 = t5 = t4 = t3 = t2 = t1 = v[0]
while 1:
t0 = v[0]
filter = t0 + 4*t1 + 6*t2 + 4*t3 + t4 - t5 - 4*t6 - 6*t7 - 4*t8 - t9
if time % s2 == 0:
if nslope == 0:
slopecrit -= slopecrit >> 4
if slopecrit < scmin: slopecrit = scmin
elif nslope >= 5:
slopecrit += slopecrit >> 4
if slopecrit > scmax: slopecrit = scmax
if nslope == 0 and abs(filter) > slopecrit:
nslope = 1
maxtime = ms160
if filter > 0:
sign = 1
else:
sign = -1
qtime = time
if nslope != 0:
if filter * sign < -slopecrit:
sign = -sign
nslope = nslope + 1
if nslope > 4:
maxtime = ms200
else:
maxtime = ms160
elif filter * sign > slopecrit and \
abs(filter) > maxslope:
maxslope = abs(filter)
if maxtime < 0:
if 2 <= nslope and nslope <= 4:
slopecrit += ((maxslope>>2) - slopecrit) >> 3
if slopecrit < scmin:
slopecrit = scmin
elif slopecrit > scmax:
slopecrit = scmax
annot.time = wfdb.strtim("i") - (time - qtime) - 4
annot.anntyp = wfdb.NORMAL
wfdb.putann(0, annot)
time = 0
elif nslope >= 5:
annot.time = wfdb.strtim("i") - (time - qtime) - 4
annot.anntyp = wfdb.ARFCT
wfdb.putann(0, annot)
nslope = 0
maxtime = maxtime - 1
t9 = t8
t8 = t7
t7 = t6
t6 = t5
t5 = t4
t4 = t3
t3 = t2
t2 = t1
t1 = t0
time = time + 1
if not wfdb.getvec(v.cast()) > 0: break
wfdb.wfdbquit()
if __name__ == "__main__":
main(sys.argv)