# How are reconstructions stored?

the `ea_reconstruction.mat` file inside the patient directory stores the data (if you use `lead group,` the `LEAD_groupanalysis.mat` file stores a copy of all patient reconstructions).

There is a single variable `reco` inside the file that stores the data.

For instance,

`reco.native.coords_mm{2}(3,:)`

will be the left (`{2}`) third lowest (`(3,:)`) contact coordinates (in x, y, z order) in native postoperative (i.e. `postop_tra.nii` , `postop_cor.nii`, `postop_sag.nii` or `rpostop_ct.nii`) space. This space is similar to the preop space except for brainshift effects. If brainshift is minimal, coordinates could thus also be used in `anat_*.nii` spaces. However, if you did run brainshift correction, there will be a fourth entry called `reco.scrf` which will be in more precisely in `anat_*.nii` space.

`reco.mni` are coordinates in MNI space.

Similarly, `reco.acpc` is an automatic (Horn et al. 2017, also see this summary) transform to AC/PC space.