# Function Naming Conventions

Full names of all VML functions include only lowercase letters for Fortran-interface, whereas for C-interface names the lowercase letters are mixed with uppercase.

VML mathematical and pack/unpack function full names have the following structure:

`v<p><name><mod>`

The initial letter v is a prefix indicating that a function belongs to VML.

The `<p>` field is a precision prefix that indicates the data type:

s

  REAL for Fortran-interface, or float for C-interface

d

  DOUBLE PRECISION for Fortran-interface, or double for C-interface.

c

  COMPLEX for Fortran-interface, or MKL_Complex8 for C-interface.

z

  DOUBLE COMPLEX for Fortran-interface, or MKL_Complex16 for C-interface.

The <name> field indicates the function short name, with some of its letters in uppercase for C-interface (see for example Table “VML Mathematical Functions” or Table “VML Service Functions”).

The <mod> field (written in uppercase for C-interface) is present in pack/unpack functions only; it indicates the indexing method used:

i

  indexing with positive increment

v

  indexing with index vector

m

  indexing with mask vector.

VML service function full names have the following structure:

vml<name>

where vml is a prefix indicating that a function belongs to VML, and <name> is the function short name, which includes some uppercase letters for C-interface (see Table “VML Service Functions”). To call VML functions from an application program, use conventional function calls. For example, the VML exponential function for single precision real data can be called as

`call vsexp ( n, a, y )` for Fortran-interface, or

`vsExp ( n, a, y );` for C-interface.

- Functions Interface

Parent topic: Vector Mathematical Functions