Hello, I submitted two functions to numpy that sum 2d matrices along angled cartesian or polar coordinates. https://github.com/numpy/numpy/pull/230 The two functions certainly have their main application in image processing and might be better suited for scipy of scikits-image. sum_angle() is not much more than the old scipy.misc.pilutils.radon() transform. But the later is deprecated and has several problems (floats, non-conserved sum(), interpolation, speed) as discussed in the pull request. The new scikits-image.transform.radon() appears to be more generic but a bit complicated and potentially even slower than the imrotate()-based version in scipy. Could sum_angle() and sum_polar() find a place in scipy or scikits-image or are they simple enough to be useful for numpy? -- Robert Jordens.