Extract lower or upper triangle from input matrices
Math Functions / Matrices and Linear Algebra / Matrix Operations
dspmtrx3
The Extract Triangular Matrix block creates a triangular matrix output from the upper or lower triangular elements of an MbyN input matrix. The block treats lengthM unoriented vector inputs as an Mby1 matrix.
The Extract parameter selects between the two components of the input:
Upper
— Copies the
elements on and above the main diagonal of the input matrix to an
output matrix of the same size. The first row of
the output matrix is therefore identical to the first row of
the input matrix. The elements below the main diagonal of the output
matrix are zero.
Lower
— Copies the
elements on and below the main diagonal of the input matrix to an
output matrix of the same size. The first column of
the output matrix is therefore identical to the first column of
the input matrix. The elements above the main diagonal of the output
matrix are zero.
The ex_extracttriang_ref model below shows the extraction of upper and lower triangles from a 5by3 input matrix.
The component of the matrix to copy to the output: upper triangle or lower triangle.
Port  Supported Data Types 

A 

U 

L 

Autocorrelation LPC  DSP System Toolbox 
Cholesky Factorization  DSP System Toolbox 
Extract Diagonal  DSP System Toolbox 
Forward Substitution  DSP System Toolbox 
LDL Factorization  DSP System Toolbox 
LU Factorization  DSP System Toolbox 
tril  MATLAB 
triu  MATLAB 