#! /bin/bash

#Apply a band-pass filter to a real datacube.

if test $# -ne 4
then
    echo 'Usage:  '$0' Input_Datacube(FITS) Freq1 Freq2 Filtered_Datacube_Name'
    if test $# -eq 0
    then
        exit 0
    else
        exit 1
    fi
fi

INPUT=$1
FREQ1=$2
FREQ2=$3
OUTNAME=$4

#Transpose the input datacube so that the x-axis is time:

rm -f BPF_TMP01.fits
switch_y_z $INPUT BPF_TMP01.fits
rm -f BPF_TMP02.fits
switch_x_y BPF_TMP01.fits BPF_TMP02.fits

#Apply the Fourier transform in the x-direction:

rm -f BPF_TMP03.fits
rfourier_x BPF_TMP02.fits BPF_TMP03.fits

#Reverse the foregoing transpose on the Fourier transform.

rm -f BPF_TMP04.fits
switch_x_y BPF_TMP03.fits BPF_TMP04.fits
rm -f TFT.fits
switch_y_z BPF_TMP04.fits TFT.fits

#Write the band-pass profile:

NZ=`print_head TFT.fits | grep NAXIS3 | awk '{print $3;}'`
DZ=`print_head TFT.fits | grep DAXIS3 | awk '{print $3;}'`

echo 'NZ = '$NZ
echo 'DZ = '$DZ

rm -f ZPROFILE.txt
echo $FREQ1 $FREQ2 $DZ $NZ | awk '{
    ind1 = int($1/$3 + 0.5);
    ind2 = int($2/$3 + 0.5);
    for (i = 0; i < $4; i++)
        if (i < ind1 || i > ind2)
            print 0.0;
        else
            print 1.0;
}' > ZPROFILE.txt

#Apply the band-pass profile to the temporal Fourier transform:

zmult_datacube TFT.fits ZPROFILE.txt

rm -f BPF_TMP05.fits
switch_y_z TFT.fits BPF_TMP05.fits
rm -f BPF_TMP06.fits
switch_x_y BPF_TMP05.fits BPF_TMP06.fits
rm -f BPF_TMP07.fits
rfourier_x BPF_TMP06.fits BPF_TMP07.fits -i
rm -f BPF_TMP08.fits
switch_x_y BPF_TMP07.fits BPF_TMP08.fits
rm -f $OUTNAME
switch_y_z BPF_TMP08.fits $OUTNAME

#Cleanup

rm -f BPF_TMP0[1-8].fits ZPROFILE.txt
#rm -f TFT.fits