lexicographic matrix rows sorting
[N, [k]]=lex_sort(M [,sel] [,'unique'])
real matrix
real matrix
column vector of integers
the lex_sort
function is now obsolete. It can be
replaced by functions gsort and unique.
N=lex_sort(M)
sorts the rows (as a group) of the
matrix M
in ascending order. If required the output
argument k
contains the ordering:
[N,k]=lex_sort(M)
returns k
such as
N
is equal to M(k,:)
.
N=lex_sort(M,sel [,'unique'])
produces the same
result as the following sequence of instructions:
The 'unique'
flag has to be given if one wants to
retain only unique rows in the result. Note that
lex_sort(M,sel,'unique')
retains only rows such that
M(:,sel) are unique.