================
Using FLENS-BLAS                                                        [TOC]
================

__FLENS-BLAS__ is built on top of __CXXBLAS__ and utilizes FLENS matrix/vector
types.  Main benefits are:

- It is easier to use as functions from FLENS-BLAS require less arguments
- Technical details like are encapsulated in the implementation and hidden
  from the user.  You pass complete matrix/vector types instead of things like
  pointers and dimensions.  This makes your code less error prone.


Toy Example
===========
We use the same example as before, i.e. we compute $y = \beta y + \alpha\,A^T x
+ z$ where $\alpha, \beta$ are scalars, $x, y, z$ are (dense) vectors and $A$
is a (general) matrix (with full storage).

Using FLENS-BLAS for this task we

- first call __mv__ which internally calls __gemv__ from CXXBLAS
- and subsequently __axpy__ which internnaly calls __axpy[1]__ from CXXBLAS.

As long as you do not compile with `-DNDEBUG` the FLENS-BLAS layer also does
some error-checking on its arguments.

Example Code
============
:import: flens/examples/tut02-page02-example.cc [stripped, downloadable]

Comments on Example Code
========================
:import: flens/examples/tut02-page02-example.cc [brief]


Compile and Run
===============

 *--[SHELL]-------------------------------------------------------------------*
 |                                                                            |
 |  cd flens/examples                                                         |
 |  g++ -Wall -std=c++11 -I../.. tut02-page02-example.cc                      |
 |  ./a.out                                                                   |
 |                                                                            |
 *----------------------------------------------------------------------------*


:links: __FLENS-BLAS__  -> doc:flens/blas/blas
        __CXXBLAS__     -> dir:cxxblas/
        __axpy__        -> file:flens/blas/level1/axpy.h
        __mv__          -> file:flens/blas/level2/mv.h
        __axpy\[1\]__   -> file:cxxblas/level1/axpy.h
        __gemv__        -> file:cxxblas/level2/gemv.h

:navigate: __up__    -> doc:flens/examples/tutorial
           __back__  -> doc:flens/examples/tut02-page01
           __next__  -> doc:flens/examples/tut02-page03