Graphmath.Quatern.from_rotation_matrix

You're seeing just the function from_rotation_matrix, go back to Graphmath.Quatern module for more information.
Link to this function

from_rotation_matrix(mat)

Specs

from_rotation_matrix(mat33()) :: quatern()

from_rotation_matrix(mat) creates a quatern from a rotation matrix.

mat is the matrix

It returns a quatern of the form {w,x,y,z}.