Re: Looking for module for shrinking a list with n-point means
Thanks John, The code u provided works for me. Indeed it is a simple requirement and I am a complete novice to Python. -Yash -- http://mail.python.org/mailman/listinfo/python-list
Re: Looking for module for shrinking a list with n-point means
On 2009-05-22 08:50, Scott David Daniels wrote: Yash Ganthe wrote: I would like to shrink a large list in the following way: If the List has 1000 integers, we need only 100 averages such that the 1000 points are average for every 10 consecutive values. So p0 to p9 will be averaged to obtain t0. p10 to p19 will be averaged to obtain t1 and so on. This is a 10-point mean. We are doing this as we collect a lot of data and plot it on a graph. Too many samples makes the graph cluttered. So we need to reduce the number of values in the way described above. Does this give you a clue? import numpy as np v = np.arange(128) v.shape = (16, 8) sum(v.transpose()) / 8. Or even: import numpy as np v = np.arange(1000).reshape((-1, 10)) ten_point_mean = v.mean(axis=1) -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco -- http://mail.python.org/mailman/listinfo/python-list
Re: Looking for module for shrinking a list with n-point means
Yash Ganthe wrote: I would like to shrink a large list in the following way: If the List has 1000 integers, we need only 100 averages such that the 1000 points are average for every 10 consecutive values. So p0 to p9 will be averaged to obtain t0. p10 to p19 will be averaged to obtain t1 and so on. This is a 10-point mean. We are doing this as we collect a lot of data and plot it on a graph. Too many samples makes the graph cluttered. So we need to reduce the number of values in the way described above. Does this give you a clue? import numpy as np v = np.arange(128) v.shape = (16, 8) sum(v.transpose()) / 8. --Scott David Daniels scott.dani...@acm.org -- http://mail.python.org/mailman/listinfo/python-list
Re: Looking for module for shrinking a list with n-point means
On May 22, 8:03 pm, Yash Ganthe wrote: > Hi, > > I would like to shrink a large list in the following way: > If the List has 1000 integers, we need only 100 averages such that the > 1000 points are average for every 10 consecutive values. So p0 to p9 > will be averaged to obtain t0. p10 to p19 will be averaged to obtain > t1 and so on. This is a 10-point mean. > > We are doing this as we collect a lot of data and plot it on a graph. > Too many samples makes the graph cluttered. So we need to reduce the > number of values in the way described above. > > Does SciPy or NumPy What do their docs say? > or any other module have functions for achieving > this? > > Which function can be used for doing this? Perhaps one like this: | >>> def n_point_means(alist, n): | ... blist = alist[:] | ... blist.sort() | ... size = len(blist) | ... assert 1 <= n <= size | ... assert size % n == 0 | ... clist = [] | ... fn = float(n) | ... for i in xrange(0, size, n): | ... clist.append(sum(blist[i:i+n]) / fn) | ... return clist | ... | >>> aaa = [9,8,7,6,5,4,3,2,0] | >>> n_point_means(aaa,2) | Traceback (most recent call last): | File "", line 1, in | File "", line 6, in n_point_means | AssertionError | >>> aaa = [9,8,7,6,5,4,3,2,1,0] | >>> n_point_means(aaa,2) | [0.5, 2.5, 4.5, 6.5, 8.5] | >>> n_point_means(aaa,5) | [2.0, 7.0] | >>> Does that do what you want? If your requirement is so simple, why not write it yourself? -- http://mail.python.org/mailman/listinfo/python-list
