r8but

r8but, an Octave code which carries out some basic linear algebra operations on R8BUT matrices (real 64 bit precision band upper triangular format).

Licensing:

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

Languages:

r8but 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:

r8but_test

linear_algebra, MATLAB codes which carry 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, is a uniform random number generator;
• r8but_det.m, returns the determinant of an R8BUT matrix;
• r8but_indicator.m, returns an R8BUT indicator matrix;
• r8but_mtv.m, multiplies a vector times an R8BUT matrix;
• r8but_mv.m, multiplies an R8BUT matrix times a vector;
• r8but_print.m, prints an R8BUT matrix;
• r8but_print_some.m, prints some of an R8BUT matrix;
• r8but_random.m, randomizes an R8BUT matrix;
• r8but_sl.m, solves A*x=b, where A is an R8BUT matrix;
• r8but_slt.m, solves A'*x=b, where A is an R8BUT matrix;
• r8but_to_r8ge.m, copies an R8BUT matrix to an R8GE matrix;
• r8but_zeros.m, zeros an R8BUT matrix;
• 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;