# CBLAS Interface to the BLAS

This appendix presents CBLAS, the C interface to the Basic Linear Algebra Subprograms (BLAS) implemented in Intel® MKL.

Similar to BLAS, the CBLAS interface includes the following levels of functions:

- “Level 1 CBLAS” (vector-vector operations)

- “Level 2 CBLAS” (matrix-vector operations)

- “Level 3 CBLAS” (matrix-matrix operations).

- “Sparse CBLAS” (operations on sparse vectors).

To obtain the C interface, the Fortran routine names are prefixed with `cblas_` (for example, dasum becomes cblas_dasum). Names of all CBLAS functions are in lowercase letters.

Complex functions ?dotc and ?dotu become CBLAS subroutines (void functions); they return the complex result via a void pointer, added as the last parameter. CBLAS names of these functions are suffixed with _sub. For example, the BLAS function cdotc corresponds to cblas_cdotc_sub.

In the descriptions of CBLAS interfaces, links provided for each function group lead to the descriptions of the respective Fortran-interface BLAS functions.