
Re: second largest element in a matrix
Posted:
May 5, 2013 12:12 AM


On 5/4/2013 9:59 PM, dpb wrote: > On 5/4/2013 7:54 PM, Nasser M. Abbasi wrote: >> On 5/4/2013 6:14 PM, tilindg1@gmail.com wrote: >> >>> IF for example, i have a matrix [3,1,1,0,2,0] >> >> this is not a matrix. it is a list of a vector. > > A vector is a 1D matrix... >
The correct definition of Matrix is
https://en.wikipedia.org/wiki/Matrix_%28mathematics%29
"In mathematics, a matrix (plural matrices) is a rectangular array of numbers, symbols, or expressions, arranged in rows and columns."
While a vector is a list. For example
http://en.wikipedia.org/wiki/Euclidean_vector
"The endpoint of a vector can be identified with an ordered list of n real numbers (ntuple). These numbers are the coordinates of the endpoint of the vector, with respect to a given Cartesian coordinate system"
ps. If one really wants to use one name for all of these objects, then may be tensor is the correct name to use and not "matrix".
A tensor of rank (or order) 1 can be represented as vector, while a tensor of rank 2 can be represented as a matrix. (these are the correct vector and matrix definitions as per above, not the matlab ones).
A tensor of rank 0 is a scalar and so on... (ps. a matrix is not always necessarily a tensor of rank 2 but a tensor of rank 2 can always be written as a matrix). i.e. tensor is a more general object.
Nasser

