cortex.polyutils.Surface¶

class
cortex.polyutils.
Surface
(pts, polys)[source]¶ Represents a single cortical hemisphere surface. Can be the white matter surface, pial surface, fiducial (midcortical) surface, inflated surface, flattened surface, etc.
Implements some useful functions for dealing with functions across surfaces.
 Parameters
 pts2D ndarray, shape (total_verts, 3)
Location of each vertex in space (mm). Order is x, y, z.
 polys2D ndarray, shape (total_polys, 3)
Indices of the vertices in each triangle in the surface.
Methods
__init__
(pts, polys)Initialize self.
approx_geodesic_distance
(verts[, m])Computes approximate geodesic distance (in mm) from each vertex in the surface to any vertex in the collection verts.
call_vtp_geodesic
(vertex)Compute geodesic distance using VTP method
create_biharmonic_solver
(boundary_verts[, …])Set up biharmonic equation with Dirichlet boundary conditions on the cortical mesh and precompute Cholesky factorization for solving it.
create_subsurface
([vertex_mask, polygon_mask])Create subsurface for efficient operations on subset of Surface
edge_collapse
(p1, p2, target)exact_geodesic_distance
(vertex)Compute exact geodesic distance along surface
extract_chunk
([nfaces, seed, auxpts])Extract a chunk of the surface using breadth first search, for testing purposes
extract_geodesic_chunk
(origin, radius)Extract a chunk of the surface that is within radius of the origin by geodesic distance.
geodesic_distance
(verts[, m, fem])Minimum mesh geodesic distance (in mm) from each vertex in surface to any vertex in the collection verts.
geodesic_path
(a, b[, max_len, d])Finds the shortest path between two points a and b.
get_connected_vertices
(vertex, mask[, …])return vertices connected to vertex that satisfy mask
get_euclidean_ball
(xyz, radius)return vertices within some 3d euclidean distance of an xyz coordinate
get_euclidean_patch
(vertex, radius[, …])return connected vertices within some 3d euclidean distance of a vertex
get_geodesic_patch
(vertex, radius[, …])return vertices within some 2d geodesic distance of a vertex (or vertices)
get_geodesic_patches
(radius[, seeds, …])create patches of cortex centered around each vertex seed
get_geodesic_strip_patch
(v0, v1, radius[, …])return patch that includes v0, v1, their geodesic path, and all points within some radius
get_strip_coordinates
(v0, v1[, …])get 2D coordinates of surface from v0 to v1
interp
(verts, vals)Interpolates a function between N knot points verts with the values vals.
lift_subsurface_data
(data[, vertex_mask])expand vertex dimension of data to original surface’s size
Compute mean curvature of this surface using the LaplaceBeltrami operator.
patches
([auxpts, n])plot_subsurface_rotating_gif
(path[, …])create a rotating gif of subsurface
polyhedra
(wm)Iterates through the polyhedra that make up the closest volume to a certain vertex
smooth
(scalars[, factor, iterations])Smooth vertexwise function given by scalars across the surface using mean curvature flow method (see http://brickisland.net/cs177fa12/?p=302).
surface_gradient
(scalars[, at_verts])Gradient of a function with values scalars at each vertex on the surface.
Attributes
Sparse vertex adjacency matrix.
Average length of all edges in the surface.
return mask of boundary vertices
Sparse matrix of vertexface associations.
Cotangent of angle opposite each vertex in each face.
return vector of edge lengths
Area of each face.
Normal vector for each face.
return pair of points on surface border that have largest pairwise geodesic distance
NetworkX undirected graph representing this Surface.
iterate through edges
LaplaceBeltrami operator for this surface.
3D matrix of points in each face: n faces x 3 points per face x 3 coords per point.
Normal vector for each vertex (average of normals for neighboring faces).