What dataformats are supported?
FieldTrip has a flexible way of supporting data formats. It uses a number of functions that provide a common interface to all electrophysiological (EEG/MEG) file formats: ft_read_header, ft_read_data and ft_read_event. Where needed, these functions will call the appropriate low-level functions for each file format. Some of the low-level functions are written by ourselves, others are supplied by the manufacturers and again others are obtained from other open source toolboxes. You can find more technical information on the reading functions on this page.
Here is a summary of the data formats that are supported by FieldTrip. Below you can find more details on some of the formats, especially regarding the MEG systems and their auxiliary files (e.g. MRI and volume conduction models). We regularly implement new data formats and this documentation may be out of date, so if yours is not listed here, please check the code.
- CTF (.ds, .res4, .meg4)
- Neuromag/Elekta (.fif)
- BTi/4D (.m4d, .pdf, .xyz, and 4D’s raw data files)
- Yokogawa/Ricoh (.ave, .con, .raw)
- Tristan BabySquid
- ANT Neuro (.avr, .cnt, .trg)
- Biosemi BDF (.bdf)
- CED - Cambridge Electronic Design (. smr)
- Electrical Geodesics, Inc. (EGI) (.egis, .ave, .gave, .ses, .raw, Meta File Format (mff))
- BESA (.avr, .swf)
- EEGLAB (.set)
- NeuroScan (.eeg, .cnt, .avg)
- Nexstim (.nxe)
- BrainVision (.eeg, .seg, .dat, .vhdr, .vmrk)
- TMSi (.Poly5)
- generic standard formats (.edf, .gdf)
The following EEG/MEG sensor formats are supported by ft_read_sens
- ASA electrode file
- FCDC Polhemus
- FIL Polhemus
- BESA positions (numeric file with accompanying .elp and .ela)
- BESA sfp
- MEG systems (CTF, Neuromag/Elekta, Yokogawa, 4D/BTi)
- SPM8 EEG
- Plexon (.nex, .plx, .ddt)
- Neuralynx (.ncs, .nse, .nts, .nev, .nrd, .dma, .log)
- CED - Cambridge Electronic Design (.smr)
- MPI - Max Planck Institute (.dap)
- Windaq (.wdq)
- ASCII-formatted data from the NIRS system from Birkbeck college, London (.txt)
- Artinis Medical Systems (.oxy3)
- EyeLink - SR Research (.asc)
The following anatomical MRI data formats are supported by ft_read_mri
- nifti (.nii / .nii.gz), using the FreeSurfer toolbox
- mgz (.mgz), using the FreeSurfer toolbox
- Analzye (.hdr, .img), using the SPM toolbox
- MINC (.mnc), using the SPM toolbox
- CTF (.mri)
- ASA (.mri, .iso)
- DICOM (.ima)
The following surface and volume mesh formats are supported by ft_read_headshape
- Generic meshes (.stl, .off)
- Visualisation Toolkit (.vtk)
- Wavefront .obj
- What dataformats are supported?
- How are the various MATLAB data structures defined?
- How can I extend the reading functions with a new dataformat?
- How can I convert an anatomical MRI from DICOM into CTF format?
- How can I convert one dataformat into an other?
- How can I import my own data format?
- How can I merge two datasets that were acquired simultaneously with different amplifiers?
- I have problems reading in neuroscan .cnt files. How can I fix this?
- Reading is slow, can I write my raw data to a more efficient file format?