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MathGroup Archive 2007

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Ordering function weird?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg82645] Ordering function weird?
  • From: Claus <claus.haslauer at web.de>
  • Date: Sat, 27 Oct 2007 05:59:25 -0400 (EDT)
  • Organization: Comp.Center (RUS), U of Stuttgart, FRG

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]?
Thanks,
Claus


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}


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