#! /bin/sh
# file: hrfft		G. Moody	14 June 1995
#			Last revised:   16 June 2003
#
# -----------------------------------------------------------------------------
# Derive a heart rate power spectrum (using tach and fft) and plot it
# Copyright (C) 2003 George B. Moody
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, see <http://www.gnu.org/licenses/>.
#
# You may contact the author by e-mail (wfdb@physionet.org) or postal mail
# (MIT Room E25-505A, Cambridge, MA 02139 USA).  For updates to this software,
# please visit PhysioNet (http://www.physionet.org/).
# _____________________________________________________________________________

X=2
XL="Frequency (Hz)"
XOPT="0 1"
Y=3
YL="Power"
YOPT=""

while [ $# -gt 1 ]
do
  case $1 in
    -a) ANNOTATOR=$2 ;;
    -f) START=$2 ;;
    -l) case $2 in
         x|X) X=0; XL="log Frequency (Hz)"; XOPT="-4 1 -lx" ;;
         y|Y) Y=1; YL="log Power"; YOPT="-ly" ;;
	 *)   X=0; XL="log Frequency (Hz)" ; XOPT="-4 1 -lx";
              Y=1; YL="log Power"; YOPT="-ly";;
	esac ;;
    -p) PLOT=$2 ;;
    -r) RECORD=$2 ;;
    -t) END=$2 ;;
    -T) DEVICE=$2 ;;
  esac
  shift
  shift
done

if [ x$PLOT = x ]; then
  if [ -x BINDIR/plt ]; then
    PLOT=BINDIR/plt
  elif [ -x /usr/local/bin/plt ]; then
    PLOT=/usr/local/bin/plt
  elif [ -x /usr/bin/plt ]; then
    PLOT=/usr/bin/plt
  elif [ -x BINDIR/plot2d ]; then
    PLOT=BINDIR/plot2d
  elif [ -x /usr/local/bin/plot2d ]; then
    PLOT=/usr/local/bin/plot2d
  elif [ -x /usr/bin/plot2d ]; then
    PLOT=/usr/bin/plot2d
  else
    echo "No plot utility found -- exiting"
    exit 1
  fi
fi

echo -n >/tmp/echo.$$
if [ -s echo.$$ ]
then
   P1=""
   P2="\\c"
else
   P1="-n"
   P2=""
fi
rm -f /tmp/echo.$$

if [ x$RECORD = x ]; then
  echo $P1 "Enter the record name: " $P2
  read RECORD
fi

if [ x$ANNOTATOR = x ]; then
  echo $P1 "Enter the annotator name: " $P2
  read ANNOTATOR
fi

if [ x$START = x ]; then
  START=0
fi

if [ x$END = x ]; then
  END=e
fi

if [ x$DEVICE = x ]; then
  PLOTOUT=""
else
  PLOTOUT="-T $DEVICE"
fi

tach -r $RECORD -a $ANNOTATOR -f $START -t $END -F 4 | \
 fft -f 4 -P -w Welch -Z - | log10 | \
 $PLOT $X $Y -x "$XL" -X $XOPT -y "$YL" $YOPT \
 -t "Record $RECORD ($START - $END): Heart rate spectrum (FFT)" $PLOTOUT