Re: Ordering function weird?

*To*: mathgroup at smc.vnet.net*Subject*: [mg82687] Re: Ordering function weird?*From*: Szabolcs Horvát <szhorvat at gmail.com>*Date*: Sun, 28 Oct 2007 04:06:55 -0500 (EST)*References*: <ffv29v$aph$1@smc.vnet.net>

Claus wrote: > Hi, > say I've got two sets of number, x and y, which I want to rank. See the > example below. I totally expect and want the result of Ordering[x]. But > I neiter understand nor expect the result of Ordering[y]. Both Sort[x] > and Sort[y] are ok. > Can anybody explain to me Ordering[y]? What do you find "weird" about it? It gives the result I expect: y[[Ordering[y]]] is the same as Sort[y]. > > > In[3]:= x = {1, 2, 3, 6, 10, 3, 4} > y = {1, 2, 7, 8, 9, 1, 2} > > Out[3]= {1, 2, 3, 6, 10, 3, 4} > > Out[4]= {1, 2, 7, 8, 9, 1, 2} > > In[5]:= Sort[x] > Sort[y] > > Out[5]= {1, 2, 3, 3, 4, 6, 10} > > Out[6]= {1, 1, 2, 2, 7, 8, 9} > > In[7]:= Ordering[x] > Ordering[y] > > Out[7]= {1, 2, 3, 6, 7, 4, 5} > > Out[8]= {1, 6, 2, 7, 3, 4, 5} > -- Szabolcs