#!/bin/sh

Usage() {
    echo "  Usage: to-two-tailed <name> [vmc]"
    echo "  <name> is the out_root given to randomise"
    echo "  e.g. if name is 'test_a' we combine single-tailed"
    echo "  test_a_vox_tstat1 and test_a_vox_tstat2 into"
    echo "  two-tailed test_a_vox_tstat (and/or the same for max, maxc)"
    echo ""
    echo "  vmc is an optional flag selecting which correction:"
    echo "  v = vox (uncorrected); m = max; c = cluster;"
    echo "  C = cluster-mass; a = all (default)."
    exit 1
}

Setup() {
    echo "Can't find avwmaths; please set-up FSL"
    exit 1
}

[ "$1" = "" ] && Usage
[ -x $FSLDIR/bin/avwmaths ] || Setup

imglob="imglob -oneperimage"

fnm=$1
vmc=$2

[ "$vmc" = "v" ] && VM="vox"
[ "$vmc" = "m" ] && VM="max"
[ "$vmc" = "c" ] && VM="maxc"
[ "$vmc" = "C" ] && VM="maxcmass"
# default to all if unspecified
[[ "$vmc" = "a" || "$vmc" = "" ]] && VM="vox max maxc maxcmass"
# print usage if mis-specified
[ "$VM" = "" ] && Usage

for vm in $VM
do
  t1=${fnm}_${vm}_tstat1
  t2=${fnm}_${vm}_tstat2
  t1g=`$imglob $t1`
  t2g=`$imglob $t2`
  if [[ -r $t1g && -r $t2g ]]
  then avwmaths $t1 -max $t2 -mul 2 -sub 1 -thr 0 ${fnm}_${vm}_tstat
  else echo "  WARNING: one of $t1 or $t2 unreadable, skipping"
  fi
done