r83_np

r83_np, an Octave code which carries out some basic linear algebra operations on R83_NP matrices (real 64 bit precision tridiagonal 3xN format, nonpivoting factorization).

These utilities are distinguished by the fact that an LU factorization is attempted without the use of pivoting. Such an approach will fail if a zero pivot is encountered, and will generally not be as accurate as a pivoting factorization. It is only recommended in cases where pivoting is known to be unnecessary, such as for a symmetric positive definite matrix.

Licensing:

The information on this web page is distributed under the MIT license.

Languages:

r83_np is available in a C version and a C++ version and a Fortran90 version and a MATLAB version and an Octave version and a Python version.

Related Data and Programs:

r83_np_test

linear_algebra, an Octave code which carries out various linear algebra operations for matrices stored in a variety of formats.

Source Code:

• r8_uniform_01.m, is a uniform random number generator;
• r83_dif2.m, returns the second difference matrix as an R83.
• r83_mtv.m, multiplies a vector times an R83 matrix;
• r83_mv.m, multiplies an R83 matrix times a vector;
• r83_print.m, prints an R83 matrix;
• r83_print_some.m, prints some of an R83 matrix;
• r83_random.m, randomizes an R83 matrix;
• r83_np_det.m, returns the determinant of a system factored by R83_NP_FA;
• r83_np_fa.m, factors an R83 linear system with no pivoting;
• r83_np_fs.m, factors and solves an R83 linear system with no pivoting;
• r83_np_ml.m, computes A * x or x * A, where A has been factored by R83_NP_FA;
• r83_np_sl.m, solves an R83 linear system factored by R83_NP_FA;
• r8vec_indicator1.m, sets an R8VEC to the indicator1 vector;
• r8vec_print.m, prints an R8VEC;