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re:sort pairs

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  • Subject: re:sort pairs
  • From: wmm at (Martin McClain)
  • Date: Mon, 15 Nov 93 10:55:13 EST

> How can I sort pairs of values -- basing the sort on the first value
> and then break ties on the second value in the pair.
> Let's say I have n pairs on numbers in the following matrix
> data = { {x1,y1}, .....{xi, yi}, .....{xn,yn} }
> Using the Sort function in Mma, I can easily sort on the xi values, but
> how can I do the secondary sort on the yi values??

I think this happens automatically.  I just tried

       Sort[ {{5,9},{2,7},{5,6},{7,1},{5,2}}]

with many permutations of the interior pairs, and the answer always comes 
out as

Isn't this exactly what you want?
Regards- Martin

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