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MatrixForm affects values instead of only printing ?????

  • To: mathgroup at smc.vnet.net
  • Subject: [mg100298] MatrixForm affects values instead of only printing ?????
  • From: summer <summertan at hotmail.com>
  • Date: Sun, 31 May 2009 06:35:42 -0400 (EDT)

Here is the example:

test1={-3, 7, 5}
test1[[3]]

returns the list and 5 as expected;

test2={-3, 7, 5}//MatrixForm
test2[[3]]

returns a column vector and error: "part 3 of blah blah doesn't exist". The actual list itself is test2[[1]]. To get the right 3rd element I have to do:

test2[[1,3]]

which returns 5 as expected.


The problem is MatrixForm is NOT supposed to change the expression it is applied on according to the manual. Is that a bug or there's logical explanation?


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