r83

r83, an Octave code which carries out some basic linear algebra operations on R83 matrices (real 64 bit precision tridiagonal 3xN format).

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

r83 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_test

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

Source Code:

• i4_log_10.m, returns the integer part of the logarithm base 10 of abs(X);
• r8_uniform_01.m, returns a pseudorandom R8.
• r83_cg.m, solves an R83 system using the conjugate gradient method.
• r83_cr_fa.m, factors an R83 system using cyclic reduction;
• r83_cr_sl.m, solves an R83 system factored by r83_cr_fa;
• r83_cr_sls.m, solves several R83 systems factored by r83_cr_fa;
• r83_dif2.m, returns the second difference matrix as an R83.
• r83_jac_sl.m, solves an R83 system using Gauss-Seidel iteration;
• r83_indicator.m, sets up an R83 indicator matrix;
• r83_jac_sl.m, solves an R83 system using Jacobi iteration;
• 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_res.m, returns the residual of an R83 linear system.
• r83_to_r8ge.m, copies an R83 matrix to an R8GE matrix;
• r83_zeros.m, zeros an R83 matrix;
• r8ge_indicator.m, returns the indicator R8GE matrix.
• r8ge_mtv.m, multiplies an R8GE matrix transposed times a vector.
• r8ge_mv.m, multiplies an R8GE matrix times a vector.
• r8ge_print.m, prints an R8GE matrix;
• r8ge_print_some.m, prints some of an R8GE matrix;
• r8vec_indicator1.m, sets an R8VEC to the indicator1 vector;
• r8vec_print.m, prints an R8VEC;
• r8vec_uniform_01.m, returns a random R8VEC;
• r8vec2_print.m, prints a pair R8VEC's;