diff --git a/src/yapsut/nearly_even_split.py b/src/yapsut/nearly_even_split.py new file mode 100644 index 0000000000000000000000000000000000000000..2f9229e7074300b33ce6a4b6d1cd92c1043d852d --- /dev/null +++ b/src/yapsut/nearly_even_split.py @@ -0,0 +1,48 @@ +def nearly_even_split(idx,nblocks,strict=False) : + """ splits a list of indexes idx into nblocks + if len(idx) can not be integer divided into nblocks + a further, shorter block is appended to accomodate the remainder samples + + keyword: strict + if True the array the remainder is appended at the last block + + Example: + x=np.arange(113) + out=nearly_even_split(x,7) + print(len(out)) + > 8 + # this is a test to check proper partition + print(abs(np.concatenate(out)-x).ptp()) + > 0 + print(out) + [array([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]), + array([16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31]), + array([32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47]), + array([48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63]), + array([64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79]), + array([80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95]), + array([ 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, + 109, 110, 111]), + array([112])] + + V 1.0 - 2023 Jan 12 - M.Maris + """ + # + import numpy as np + # + rembloc=int(np.mod(len(idx),nblocks)) + + if strict and rembloc > 0 and nblocks>1: + rembloc=np.mod(len(idx),nblocks-1) + dblock=len(idx)//(nblocks-1) + EVEN=dblock*(nblocks-1) + out=list(np.split(idx[:EVEN],(nblocks-1))) + if rembloc > 0 : + out.append(idx[EVEN:]) + else : + dblock=len(idx)//nblocks + EVEN=dblock*nblocks + out=list(np.split(idx[:EVEN],nblocks)) + if rembloc > 0 : + out.append(idx[EVEN:]) + return out