Re: How to concatenate matrices?

*To*: mathgroup at smc.vnet.net*Subject*: [mg113098] Re: How to concatenate matrices?*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Wed, 13 Oct 2010 12:39:01 -0400 (EDT)

On 10/12/10 at 1:49 PM, emammendes at gmail.com (Eduardo M. A. M.Mendes) wrote: >Although I read the help on matrices, I could not figure out how to >concatenate two matrices. >What I have is: >B1 - (vector) - as a result of P21.x1 (product of a matrix and a >vector) >B2 - (vector) - as a result of P22.x2 >B=[B1,B2] - that is, a matrix with two columns. Mathematica syntax 101 states square brackets are *always* used to group arguments to a function. And since the notation B=[B1,B2] doesn't use any defined function, this cannot possibly be correct. You should have gotten an error message if that is what you tried. >Join, Append, and all sort of funny functions return even funnier >results (elements with {}). From your description above, the result you want should be achieved by doing Transpose[{B1, B2}] If this doesn't work for you, try posting an example of what you did and what it is you want to achieve and you will likely get a better answer.