On Feb 17, 8:24 pm, John Posner <jjpos...@optimum.net> wrote: > On 2/17/2010 1:10 PM, 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... > > The lines above show that you are using two different series of index > values. Each function call (more properly, "method call") has the form: > > frames[INDEX_FROM_FIRST_SERIES].func(INDEX_FROM_SECOND_SERIES) > > (I've dropped the underscores in the names, for simplicity.) You're > getting hung up trying to keep the two series of index values in sync. > But you don't really need to. More below ... > > > > > > > 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! > > As you've shown above, a "for" loop takes care of the first series of > index values: > > for index in xrange(num_frames): # "0" arg unnecessary > frames[index].func(INDEX_FROM_SECOND_SERIES) > > The second series of index values needs to look like this: > > 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3 ... > > The trick is not to worry about matching the second series to the first > series. Instead, create an "infinite" second series using a Python > generator, and use as many of its values as you need. Don't worry about > the unused values, because the series isn't *really* infinite. :-) > > Here's an easy way to create the generator > > import itertools > second_series_gen = (i/4 for i in itertools.count()) > > Now, every time you need another number from this series, use its next() > method. So the above code becomes: > > for index in xrange(num_frames): > frames[index].func(second_series_gen.next()) > > -John
That's a cool trick, but maybe I wasn't specific enough. The values series are the range of values that the frames.func() function should use, it should not overflow, and I would want the function to use as evenly distributed number of values as possible from the first series. The "0000,1111" was just an example. Let me see if I can be more specific: values = [2, 3, 4] frames = [obj1, obj2, obj3, obj4, obj5, obj6] And the calls: frames[0].func(values[0]) # func.(values[2]) frames[1].func(values[0]) # func.(values[2]) frames[2].func(values[1]) # func.(values[3]) frames[3].func(values[1]) # func.(values[3]) frames[4].func(values[2]) # func.(values[4]) frames[5].func(values[2]) # func.(values[4]) However the values list might have an uneven number of items. I would like to make it as evenly distributed as possible, e.g.: values = [-2, -1, 0] frames = [obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8] frames[0].func(values[0]) # func.(values[-2]) frames[1].func(values[0]) # func.(values[-2]) frames[2].func(values[1]) # func.(values[-2]) frames[3].func(values[1]) # func.(values[-1]) frames[4].func(values[1]) # func.(values[-1]) frames[5].func(values[2]) # func.(values[-1]) frames[6].func(values[2]) # func.(values[0]) frames[7].func(values[2]) # func.(values[0]) I'll be even more specific. I have a Minimum and Maximum value that the user enters. The frame.func() function is a "translate" function, it basically moves a frame in the application in one direction or another depending on the argument value. So frame[0].func(2) would move the frame[0] 2 pixels to the right. So what I want is the function to create a smooth transition of all the frames from the Minimum to the Maximum value. If minimum was 0, and maximum was 10, I'd want the first frame moved 0 pixels (it stays in place), the last frame to move 10 pixels, and the frames between are gradually moved from 1 pixels to 9 pixels relative from their positions. Perhaps I'm just overcomplicating. I'll have a look at some drawing apps and see how they've implemented drawing straight lines under an angle, I guess that could be called a gradual change of values. Thanks for all the suggestions everyone, I'll have a look at the rest shortly. -- http://mail.python.org/mailman/listinfo/python-list
