Re: Partition a list based on columns

*To*: mathgroup at smc.vnet.net*Subject*: [mg119681] Re: Partition a list based on columns*From*: Heike Gramberg <heike.gramberg at gmail.com>*Date*: Fri, 17 Jun 2011 00:09:24 -0400 (EDT)*References*: <201106160802.EAA13329@smc.vnet.net>

For the first part of your question you could use Transpose[Partition[Sort[Flatten[{{3,1},{2,4}}]]],2]] For the second part you could do something like diag[list_, k_, l_] := With[{order = Flatten[Table[{i, j - i + 1}, {j, 1, k + l - 1}, {i, Max[j + 1 - l, 1], Min[j, k]}], 1]}, ReplacePart[ConstantArray[0, {k, l}], Thread[order -> PadRight[list, k l]]]] then diag[list,k,l] would order list into a k-by-l matrix in a diagonal way (truncating or extending list if necessary), so for example diag[Range[12], 3, 4] gives {{1, 2, 4, 7}, {3, 5, 8, 10}, {6, 9, 11, 12}} Heike. On 16 Jun 2011, at 09:02, StatsMath wrote: > Hi All, > > I am looking for help in partition a list based on columns. For ex, > given a list {{3,1},{2,4}}, I want to sort it and then partition it > along columns. > > So for the given example, I want the answer to be, {{1,3},{2,4}}. > > Right now If I try, Partition[Sort[Flatten[{{3,1},{2,4}}]]],2], I get > {{1,2},{3,4}}. > > Looking at doc for Partition[], it doesn't seem to support aligning > rows on columns. I can do it in a For[] loop, but that seems un- > mathematica like, is there a good functional way to do this?? > > ------------ > > What would be a good way to line up elements in a list in a diagonal > fashion, for ex: from Range[9] want to create the follwing matrix: > > 1 2 4 > 3 5 7 > 6 8 9 > > Thanks in advance! >

**References**:**Partition a list based on columns***From:*StatsMath <stats.math8@gmail.com>