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Triangular matrices:
In mathematics, a triangular matrix is a special kind of square matrix. A square matrix is called lower triangular if all the entries above the main diagonal are zero. Similarly, a square matrix is called upper triangular if all the entries below the main diagonal are zero... Wikipedia: Triangular matrix
Multiplying lower triangular matrices
Multiplying upper triangular matrices
The inverse of a lower triangular matrix:
The inverse of an upper triangular matrix:
Eigenvalues and eigenvectors of a diagonal matrix:
Eigenvalues and eigenvectors of a lower triangular matrix:
Eigenvalues and eigenvectors of a upper triangular matrix:
Code study
Diagonal matrix:
- rdiag_mR(); ... ... ... ... ... ... ... ... . Octave version
Lower triangular matrix:
- rlower_mR(); ... ... ... ... ... ... ... ... Octave version
Upper triangular matrix:
- rupper_mR(); ... ... ... ... ... ... ... ... Octave version
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