| Symbolic Math Toolbox | |
Syntax
tril(X) tril(X,K)
Description
tril(X) is the lower triangular part of X.
tril(X,K) returns a lower triangular matrix that retains the elements of X on and below the k-th diagonal and sets the remaining elements to 0. The values k=0, k>0, and k<0 correspond to the main, superdiagonals, and subdiagonals, respectively.
A = [ a, b, c ] [ 1, 2, 3 ] [ a+1, b+2, c+3 ]Then
tril(A) returns
[ a, 0, 0 ] [ 1, 2, 0 ] [ a+1, b+2, c+3 ]
tril(A,1) returns
[ a, b, 0 ] [ 1, 2, 3 ] [ a+1, b+2, c+3 ]
triu(A,-1) returns
[ 0, 0, 0 ] [ 1, 0, 0 ] [ a+1, b+2, 0 ]
| | taylortool | triu | |