// 28 Jun 2009
function y = circ(g)
// locates the vertices in the circle of radius 200
function y = k(n)
//complete graph on n vertices K_n
function y = w(n)
//wheel graph, W_n (a cycle with a central vertex added)
function y = prufer(code)
// prufer code to tree
function code = tree2prufer(a)
// tree to prufer code
function y = c(n)
//cycle graph on n vertices C_n
function y = p(n)
//path graph on n vertices P_n
function y = prism(n)
// prism from an n-polygon
function y = ladder(n)
// a ladder with n steps
function y = grid(n,m)
// an n x m 2d grid
function y = line(g)
// the line graph from g
function y = kp(n,m)
// the complete bipartite graph k_n,m
function y = q(n)
// hypercube of dimension n, Q_n (has 2^n vertices)
function y = dodecahedron
// the dodecahedron graph
function p = product(g,h)
// Graph product of g and h
function p = disjointunion(g,h)
// disjoint union of g and h
// see also graph_union
function g=book(m)
// a book with n pages P_2 x star K_1,m
function g = octahedral()
// octahedral graph (dual to cube)
function g = tetrahedral()
// grid of simplex
function g = cubial()
// cube is 3 - dimensional hypecube
function g = readedgelist(s)
// this is the format of that adj2edge translates to
function g = readadjlist(s)
// this is the format of that adj2edge translates from
// Eigenvalue / Eigenvector ploting routines
function y = ea(g)
// Eigenvector Adjacency, two largest eigenvalues
// largest eigenvector is useless in regular graphs
function y = eaxy(g,x,y)
// Eigenvector Adjacency, two eigenvalues, x and y
function y = scalegraph(g, s)
// Scales the display of g by the factor s
function y = translategraph(g, x, y)
// translates the display of g by the factor (x, y)
function y = rotategraph(g, theta)
// rotates the graph theta radians ccw
function y = el(g)
// Eigenvector Laplacian, small eigenvectors, 2 and 3
function y = elxy(g, x, y)
// Eigenvector Laplacian, eigenvectors $-x, $-y
// Smallest eigenvalue useless
function y = eld(g)
// not a good idea
function y = centriod(g)
// not a good idea
function y = spectraldraw(g, p)
// from  Yehuda Koren
// Drawing Graphs by Eigenvectors: Theory and Practice
// Something is wrong, it doesn't give the same answers
// I needed to add an escape counter 
// The test matrix was k_1,4???
function y = specdraw(g)
// 3d graphs drawings
function gplot3d(g)