# sNewAbstractStream

Creates and initializes an abstract random stream for single precision floating-point arrays.

## Syntax

Fortran:

status = vslsnewabstractstream( stream, n, sbuf, a, b, scallback )

C:

status = vslsNewAbstractStream( &stream, n, sbuf, a, b, scallback );

## Description

This function creates a new abstract stream for single precision floating-point arrays with random numbers of the uniform distribution over interval (a,b). The function associates the stream with a single precision array sbuf and user’s callback function scallback that is intended for updating of sbuf content.

## Input Parameters

Name | Type | Description
--- | --- | ---
n | FORTRAN: INTEGER, INTENT(IN) C: int | Size of the array sbuf
sbuf | FORTRAN: REAL, INTENT(IN) C: float* | Array of n single precision floating-point random numbers with uniform distribution over interval (a,b)
a | FORTRAN: REAL, INTENT(IN) C: float | Left boundary a
b | FORTRAN: REAL, INTENT(IN) C: float | Right boundary b
scallback | FORTRAN: See Note below C: See Note below | FORTRAN: Address of the callback function used for update of the array sbuf C: Pointer to the callback function used for update of the array sbuf

## Output Parameters

Name | Type | Description
--- | --- | ---
stream | FORTRAN: TYPE(VSL_STREAM_STATE), INTENT(OUT) C: VSLStreamStatePtr* | Descriptor of the stream state structure

### Note

Format of the callback function in Fortran:
`INTEGER FUNCTION SUPDATEFUNC[C]( stream, n, sbuf, nmin, nmax, idx )`
`TYPE(VSL_STREAM_STATE),POINTER :: stream[reference]`
`INTEGER(KIND=4),INTENT(IN) :: n[reference]`
`REAL(KIND=4), INTENT(OUT) :: sbuf[reference](0:n-1)`
`INTEGER(KIND=4),INTENT(IN) :: nmin[reference]`
`INTEGER(KIND=4),INTENT(IN) :: nmax[reference]`
`INTEGER(KIND=4),INTENT(IN) :: idx[reference]`

Format of the callback function in C:
`int sUpdateFunc( VSLStreamStatePtr stream, int* n, float sbuf[], int* nmin, int* nmax, int* idx );`

The callback function returns the number of elements in the array actually updated by the function. Tablescallback Callback Function Parameters gives the description of the callback function parameters.

scallback Callback Function Parameters
Parameters | Short Description
--- | ---
stream | Abstract stream descriptor
n | Size of sbuf
sbuf | Array of random numbers associated with the stream stream
nmin | Minimal quantity of numbers to update
nmax | Maximal quantity of numbers that can be updated
idx | Position in cyclic buffer sbuf to start update `0 ≤ idx < n`.

## Return Values

VSL_ERROR_OK, VSL_STATUS_OK
  Indicates no error, execution is successful.
VSL_ERROR_BAD_ARG
  Parameter n is not positive.
VSL_ERROR_MEM_FAILURE

  System cannot allocate memory for stream.

VSL_ERROR_NULL_PTR

  Either buffer or callback function parameter is a NULL pointer.

Parent topic: Service Routines