===========================
First BLAS Level 2 Function                                          [TOC]
===========================

- In a first approach we will implement the BLAS Level 2 functions by
  using Level 1 functions as building blocks.
- Each function should distinguish the cases that a matrix is row or column
  major.


`ger`: General Matrix Rank 1 Update
===================================

   +--------------------------------+---------------------------------------------------------+
   | Operation                      | Signature                                               |
   +--------------------------------+---------------------------------------------------------+
   | $\alpha xy^T+A\rightarrow A$   | ==== CODE(Type=c)====================================== |
   |                                | void                                                    |
   |                                | dger(size_t m, size_t n, double alpha,                  |
   |                                |      const double *x, ptrdiff_t incX,                   |
   |                                |      const double *y, ptrdiff_t incY,                   |
   |                                |      double *A, ptrdiff_t incRowA, ptrdiff_t incColA);  |
   |                                | ======================================================= |
   +--------------------------------+---------------------------------------------------------+

In the special case $\alpha = 0$ or $m=0$ or $n=0$ this is a NOP.


# `gemv`: General Matrix Vector Product
# =====================================
# 
#    +--------------------------------------+---------------------------------------------------------------+
#    | Operation                            | Signature                                                     |
#    +--------------------------------------+---------------------------------------------------------------+
#    | $\alpha A x + \beta y \rightarrow y$ | ==== CODE(Type=c)============================================ |
#    |                                      | void                                                          |
#    |                                      | dgemv(size_t m, size_t n, double alpha,                       |
#    |                                      |       const double *A, ptrdiff_t incRowA, ptrdiff_t incColA,  |
#    |                                      |       const double *x, ptrdiff_t incX,                        |
#    |                                      |       double beta,                                            |
#    |                                      |       double *y, ptrdiff_t incY);                             |
#    |                                      | ============================================================= |
#    +--------------------------------------+---------------------------------------------------------------+
# 
# 
# - In the special case $\beta = 0$ vector $y$ must not be multiplied by $0$ but overwritten with zeros.  So
#   in this case $y$ might contain `NaN` entries.
# - In the special case 

Exercise
========

Complete the following code

:import: session04/blas2_ex.c

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