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Add "IntendedFor" field to BIDS field map jsons for the associated fMRI and DWI scans based on acquisition time.
import json
import bisect
from glob import glob
from os.path import join, splitext
from bids.grabbids import BIDSLayout
from dateutil.parser import parse
# subj_dir *must* have trailing /
subj_dir = '/scratch/tsalo006/dset/sub-01/'
sess = '01'
data_suffix = '.nii.gz'
layout = BIDSLayout(subj_dir)
def files_to_dict(file_list):
"""Convert list of BIDS Files to dictionary where key is
acquisition time (datetime.datetime object) and value is
the File object.
out_dict = {}
for f in file_list:
fn = f.filename
with open(fn, 'r') as fi:
data = json.load(fi)
dt = parse(data['AcquisitionDateTime'])
out_dict[dt] = f
return out_dict
# Get json files for field maps
fmap_jsons = layout.get(session=sess, modality='fmap', extensions='json')
for dir_ in ['AP', 'PA']:
# Run field map directions independently
dir_jsons = [fm for fm in fmap_jsons if '_dir-{0}_'.format(dir_) in fm.filename]
fmap_dict = files_to_dict(dir_jsons)
dts = sorted(fmap_dict.keys())
intendedfor_dict = {fmap.filename: [] for fmap in dir_jsons}
# Get all scans with associated field maps (bold + dwi)
func_jsons = layout.get(session=sess, type='bold', extensions='json') +\
layout.get(session=sess, type='dwi', extensions='json')
func_dict = files_to_dict(func_jsons)
for func in func_dict.keys():
fn, _ = splitext(func_dict[func].filename)
fn += data_suffix
fn = fn.split(subj_dir)[-1]
# Find most immediate field map before scan
idx = bisect.bisect_right(dts, func) - 1
fmap_file = fmap_dict[dts[idx]].filename
for fmap_file in intendedfor_dict.keys():
with open(fmap_file, 'r') as fi:
data = json.load(fi)
# No overwriting, for now
if 'IntendedFor' not in data.keys():
data['IntendedFor'] = intendedfor_dict[fmap_file]
with open(fmap, 'w') as fo:
json.dump(data, fo)
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utooley commented Feb 6, 2019

Updated a few things in my fork since it seems pybids has changed a bit.

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