Re: Convert nxn matrix to a column vector with (n^2) elements
- To: mathgroup at smc.vnet.net
- Subject: [mg83731] Re: Convert nxn matrix to a column vector with (n^2) elements
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Thu, 29 Nov 2007 06:26:05 -0500 (EST)
- Organization: The Open University, Milton Keynes, UK
- References: <fiji4u$ijb$1@smc.vnet.net>
Tara.Ann.Lorenz at gmail.com wrote:
> Any ideas how to convert an nxn matrix to a column vector with n^2
> elements?
Beware that Mathematica does not have any special construct to
distinguish row vectors from column vectors. A vector can be represented
by a one dimensional list made of numeric or/and symbolic elements.
Depending on the context and the operation in use, Mathematica
interprets the vector as a column or a row vector. (More generally,
vectors are tensors of rank 1.)
Having said that, I believe that what you are looking for is a command
of the form Flatten@Transpose@m (m being your square matrix) as
illustrated in the following example:
Mathematica 6.0 for Microsoft Windows (32-bit)
Copyright 1988-2007 Wolfram Research, Inc.
In[1]:= m = Array[a, {2, 2}]
Out[1]= {{a[1, 1], a[1, 2]}, {a[2, 1], a[2, 2]}}
In[2]:= %//MatrixForm
Out[2]//MatrixForm= a[1, 1] a[1, 2]
a[2, 1] a[2, 2]
In[3]:= Flatten@Transpose@m
Out[3]= {a[1, 1], a[2, 1], a[1, 2], a[2, 2]}
In[4]:= %//MatrixForm
Out[4]//MatrixForm= a[1, 1]
a[2, 1]
a[1, 2]
a[2, 2]
In[5]:= Flatten@m
Out[5]= {a[1, 1], a[1, 2], a[2, 1], a[2, 2]}
In[6]:= %//MatrixForm
Out[6]//MatrixForm= a[1, 1]
a[1, 2]
a[2, 1]
a[2, 2]
Regards,
--
Jean-Marc