Silly question on Matrices
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From: Simon on 5 Aug 2010 07:00 This is such a common Mathematica gotcha that it should be documented properly. The MatrixForm documentation says: MatrixForm acts as a "wrapper", which affects printing, but not evaluation. Which is true provided you know your Mathematica operator ordering. Maybe the docs need a Possible Issues section?? On Aug 4, 7:51 pm, "Eduardo M. A. M.Mendes" <emammen...(a)gmail.com> wrote: > Hello there > > I am new to Mathematica. In one of my attempts to understand how it works, > I tried the following example > > A={{1,2,3},{4,5,6},{7,8,9}} //MatrixForm > > The result seems to be a matrix 3x3 but when I try A[[1][1]], the whole > first line shows up instead of just one element. If I don't use MatrixForm, > it works fine. How can I see a matrix in nice format without wrecking > everything? > > Many thanks > > Ed
From: Eduardo M. A. M.Mendes on 5 Aug 2010 07:01
Many thanks to all for the replies. Regards Ed -----Original Message----- From: Bob Hanlon [mailto:hanlonr(a)cox.net] Sent: Wednesday, August 04, 2010 9:18 AM Subject: Re: Silly question on Matrices Use parentheses to exclude MatrixForm from the definition of A (A = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}) // MatrixForm A[[1, 1]] 1 A[[1]][[1]] 1 Bob Hanlon ---- "Eduardo M. A. M.Mendes" <emammendes(a)gmail.com> wrote: ============= Hello there I am new to Mathematica. In one of my attempts to understand how it works, I tried the following example A={{1,2,3},{4,5,6},{7,8,9}} //MatrixForm The result seems to be a matrix 3x3 but when I try A[[1][1]], the whole first line shows up instead of just one element. If I don't use MatrixForm, it works fine. How can I see a matrix in nice format without wrecking everything? Many thanks Ed |