**r8gb**,
a MATLAB code which
carries out some basic linear algebra operations on R8GB matrices
(real 64 bit precision general banded format).

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

**r8gb** is available in
a C version and
a C++ version and
a FORTRAN90 version and
a MATLAB version and
a Python version

linear_algebra, MATLAB codes which carry out various linear algebra operations for matrices stored in a variety of formats.

- 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;
- r8gb_det.m, computes the determinant of an R8GB matrix factored by R8GB_FA or R8GB_TRF;
- r8gb_dif2.m, returns the second difference matrix in R8GB format.
- r8gb_fa.m, performs a LINPACK style PLU factorization of an R8GB matrix;
- r8gb_indicator.m, returns an R8GB indicator matrix;
- r8gb_ml.m, computes A*x or A'*x after A has been factored by R8GB_FA;
- r8gb_mtv.m, multiplies a vector times an R8GB matrix;
- r8gb_mu.m, computes A*x or A'*x after A has been factored by R8GB_TRF;
- r8gb_mv.m, multiplies an R8GB matrix times a vector;
- r8gb_nz_num.m, counts the nonzeroes in an R8GB matrix;
- r8gb_print.m, prints an R8GB matrix.;
- r8gb_print_some.m, prints some of an R8GB matrix;
- r8gb_random.m, randomizes an R8GB matrix;
- r8gb_sl.m, solves a system factored by R8GB_FA;
- r8gb_to_r8ge.m, copies an R8GB matrix to an R8GE matrix;
- r8gb_to_r8s3.m, copies an R8GB matrix to an R8S3 matrix;
- r8gb_to_r8sp.m, copies an R8GB matrix to an R8SP matrix;
- r8gb_to_r8vec.m, copies an R8GB matrix to an R8VEC;
- r8gb_trf.m, performs a LAPACK style PLU factorization of an R8GB matrix;
- r8gb_trs.m, solves a linear system factored by R8GB_TRS;
- r8gb_zeros.m, zeros an R8GB matrix;
- r8ge_det.m, computes the determinant of a factored R8GE matrix;
- r8ge_fa.m, factors an R8GE matrix;
- r8ge_print.m, prints an R8GE matrix;
- r8ge_print_some.m, prints some of an R8GE matrix;
- r8ge_random.m, returns a random R8GE matrix;
- r8ge_to_r8gb.m, converts an R8GE matrix to an R8GB matrix;
- r8ge_to_r8vec.m, converts an R8GE matrix to an R8VEC;
- r8s3_print.m, prints an R8S3 matrix;
- r8s3_print_some.m, prints some of an R8S3 matrix;
- r8sp_print.m, prints an R8SP matrix;
- r8sp_print_some.m, prints some of an R8SP matrix;
- r8vec_indicator1.m, sets an R8VEC to the indicator1 vector;
- r8vec_print.m, prints an R8VEC;
- r8vec_to_r8gb.m, converts an R8VEC to an R8GB matrix;
- r8vec_to_r8ge.m, converts an R8VEC to an R8GE matrix;
- r8vec2_print.m, prints a pair R8VEC's;