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Re: Sorting Rows of a Matrix


Hi Greg,
you can solve thhis problem by using the second argument of Sort (see 
the manual). E.g. r will choose the sorting row:

m={{1,3},{2,2},{3,1}};
r=1;
Sort[m, #1[[r]] < #2[[r]] &]

with r=2 we get: {{1, 3}, {2, 2}, {3, 1}}
with r=2 we get: {{3, 1}, {2, 2}, {1, 3}}

Daniel

Gregory Lypny wrote:
> Hello everyone,
> 
> How can I sort the rows of a matrix by using one or more of the  
> columns as sort keys just like in a spreadsheet?  For example, if  
> matrix M is 12 x 2 with numbers in the first column and unordered  
> month numbers in the second, how would I order the rows by month?
> 
> 	Regards,
> 
> 		Greg
> 


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