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%% Exponentiate vector field % Changed: Dec 31st, 2011 % function [vx,vy,vz] = expfield(vx, vy, vz) % Find n, scaling parameter normv2 = vx.^2 + vy.^2 + vz.^2; m = sqrt(max(normv2(:))); n = ceil(log2(m/0.5)); % n big enough so max(v * 2^-n) < 0.5 pixel) n = max(n,0); % avoid null values % Scale it (so it's close to 0) vx = vx * 2^-n; vy = vy * 2^-n; vz = vz * 2^-n; % square it n times for i=1:n [vx,vy,vz] = compose(vx,vy,vz, vx,vy,vz); end end