# BLAS and Sparse BLAS Routines

This chapter contains descriptions of the BLAS and Sparse BLAS routines of the Intel® Math Kernel Library. The routine descriptions are arranged in several according to the BLAS level of operation:

- BLAS Level 1 Routines (vector-vector operations)

- BLAS Level 2 Routines (matrix-vector operations)

- BLAS Level 3 Routines (matrix-matrix operations)

- Sparse BLAS Level 1 Routines (vector-vector operations).

- Sparse BLAS Level 2 and Level 3 Routines (matrix-vector and matrix-matrix operations)

Each section presents the routine and function group descriptions in alphabetical order by routine or function group name; for example, the ?asum group, the ?axpy group. The question mark in the group name corresponds to different character codes indicating the data type (`s`, `d`, `c`, and `z` or their combination); see Routine Naming Conventions.

When BLAS or Sparse BLAS routines encounter an error, they call the error reporting routine xerbla.

In BLAS Level 1 groups i?amax and i?amin, an “`i`” is placed before the character code and corresponds to the index of an element in the vector. These groups are placed in the end of the BLAS Level 1 section.

- Sparse BLAS Level 1 Routines
- Sparse BLAS Level 2 and Level 3 Routines