samer@4: function b=measure(x,l)
samer@4: % measure - returns vector in given direction but with a different length
samer@4: %
samer@4: % measure :: [[N]] -> [[N]] ~'unit vector of length 1'.
samer@4: % measure :: [[N]], L:nonneg -> [[N]] ~'vector of length L'.
samer@4: 
samer@4: if nargin<2, l=1; end
samer@4: b=(l/norm(x))*x;