Project MEG sensor location info to 2D plane


I am trying to use mne.viz.plot_topomap() to project data onto the brain. The second argument of the function is pos, whose shape ought to be (n_channel, 2), where 2 represents the x and y coordinates of data points. However, the location information for each channel in the raw data is an array of size 12, which is the position plus the normal given by a 3x3 rotation matrix (a description given by the documentation). I guess the location info from raw data is somehow 3D (though I don’t understand what is a rotation matrix), while the mne.viz.plot_topomap function plots sensor locations on a 2D plane. Is there a way to convert the raw location (represented by an array of 12 numbers) to something that can be accepted by the mne.viz.plot_topomap function (two numbers)? Thank you!

  • MNE version: 1.0.3
  • operating system: macOS