Data Set I. Swiss rolls

Swiss roll (Donoho-Grimes)

n = 1000;

tt = (3*pi/2)*(1+2*rand(1,n)); height = 21*rand(1,n);

X = [tt.*cos(tt); height; tt.*sin(tt)];

Swiss roll with a rectangular hole

N=400;

tt1 = (pi/2)*(1+2*rand(1,1.2*N));

height1 = 21*rand(1,1.2*N);

tt2 = pi*(1+2*rand(1,N));

height2 = 7*rand(1,N);

tt3 = pi*(1+2*rand(1,N));

height3 = 7*(2+rand(1,N));

tt4 = pi*(3+2*rand(1,3*N));

height4 = 21*rand(1,3*N);

X1 = [tt1.*cos(tt1); height1; tt1.*sin(tt1)];

X2 = [tt2.*cos(tt2); height2; tt2.*sin(tt2)];

X3 = [tt3.*cos(tt3); height3; tt3.*sin(tt3)];

X4 = [tt4.*cos(tt4); height4; tt4.*sin(tt4)];

X = [X1 X2 X3 X4];

n = size(X,2);