To get a cylindrical noise field in Wilbur, use Filter>>Calculate Height Field. Select Type=Math Function and enter "ridged(1*cos(2*pi*ix/ixsize),1*sin(2*pi*ix/ixsize),4*iy/iysize)" as the expression. The 1* terms are the radius of the cylinder in noise space (larger values will get smaller noise) and the 4* term is the height of the cylinder in noise space. "ridged(x,y,z)" is the ridged fractal noise function ( "fbm(x,y,z)" is the fractional brownian motion function ). The "ix/ixsize" term computes a function from 0 to 1 horizontally in the image; the "iy/iysize" term computes a function from 0 to 1 vertically in the image. 2*pi*t converts a number from 0 to 1 into one ranging from o to two*pi (in other words, an angle). The cos(t),sin(t) item computes x and y from an angle t.