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Strange behavior with comment

  • To: mathgroup at smc.vnet.net
  • Subject: [mg118655] Strange behavior with comment
  • From: Virgil Stokes <vs at it.uu.se>
  • Date: Fri, 6 May 2011 07:22:34 -0400 (EDT)

The following gives an error,

m = 4;
k = 3;
IntegerPartitions[ m, {k}]; (* Get all integer partitions that are exactly of 
length k *)
Permutations /@ %; (* Get all permutations of the integer partitions *)
Flatten[%, 1]  (* Flatten the list *)
Apply[Multinomial, %, {1}]  (* Apply Multinomial to each element of the list % *)
ns = Plus @@ %

Flatten::normal: Nonatomic expression expected at position 1 in Flatten[3,1]. >>

Flatten[3, 1]

However, if I remove the comment from the entry in the line before Flatten, then 
it gives the correct results,

m = 4;
k = 3;
IntegerPartitions[m, {k}]; (* Get all integer partitions that are exactly of 
length k *)
Permutations /@ %;
Flatten[%, 1]  (* Flatten the list *)
Apply[Multinomial, %, {1}] (* Apply Multinomial to each element of the list % *)
ns = Plus @@ %

{{2, 1, 1}, {1, 2, 1}, {1, 1, 2}}

{12, 12, 12}

36

Why does this happen?





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