This is documentation for Mathematica 7, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)

LowerTriangularize

LowerTriangularize[m]
gives a matrix in which all but the lower triangular elements of m are replaced with zeros.
LowerTriangularize[m, k]
replaces with zeros only the elements above the k^(th)subdiagonal of m.
  • In LowerTriangularize[m, k] positive k refers to subdiagonals above the main diagonal and negative k refers to subdiagonals below the main diagonal.
Get the lower triangular part of a matrix:
Get the strictly lower triangular part of a matrix:
Get the lower triangular part of a matrix:
In[1]:=
Click for copyable input
Out[1]//MatrixForm=
 
Get the strictly lower triangular part of a matrix:
In[1]:=
Click for copyable input
Out[1]//MatrixForm=
Get the lower triangular part of nonsquare matrices:
The number of rows or columns limits the meaningful values of the parameter k:
New in 7