Andrej Mitrovic wrote: > Hi, > > I couldn't figure out a better description for the Subject line, but > anyway, I have the following: > > _num_frames = 32 > _frames = range(0, _num_frames) # This is a list of actual objects, > I'm just pseudocoding here. > _values = [0, 1, 2, 3, 4] > > I want to call a function of _frames for each frame with a _values > argument, but in a way to "spread out" the actual values. > > I would want something similar to the following to be called: > > _frames[0].func(_values[0]) > _frames[1].func(_values[0]) > _frames[2].func(_values[0]) > _frames[3].func(_values[0]) > _frames[4].func(_values[1]) > _frames[5].func(_values[1]) > _frames[6].func(_values[1]) > _frames[7].func(_values[1]) > _frames[8].func(_values[2]) > ...etc... > > Both the _values list and _frames list can be of variable and uneven > size, which is what is giving me the problems. I'm using Python 2.6. > > I've tried the following workaround, but it often gives me inaccurate > results (due to integer division), so I had to add a safety check: > > num_frames = 32 > values = [0, 1, 2, 3, 4] > offset_step = num_frames / len(values) > for index in xrange(0, num_frames): > offset = index / offset_step > if offset > offset_values[-1]: > offset = offset_values[-1] > frames[index].func(values[offset]) > > There has to be a better way to do this. I'd appreciate any help. > Cheers!
I tried to apply http://en.wikipedia.org/wiki/Bresenham's_line_algorithm on the problem: def bresenham(xitems, yitems): x1 = len(xitems) y1 = len(yitems) assert y1 <= x1 assert x1 > 0 deltax = x1-1 deltay = y1-1 error = deltax // 2 yitems = iter(yitems) y = next(yitems) for x in xitems: yield x, y error -= deltay if error < 0: y = next(yitems) error += deltax if __name__ == "__main__": def make_f(i): def f(v): return "%d --> %s" % (i, v) return f functions = [make_f(i) for i in range(11)] values = ["b%s" % k for k in range(5)] for f, v in bresenham(functions, values): print f(v) The implementation is derived from the code on the wikipedia page and untested. Peter -- http://mail.python.org/mailman/listinfo/python-list
