# ExecX

Computes convolution or correlation for multidimensional case with the fixed first operand vector.

## Syntax

Fortran:

status = vslsconvexecx(task, y, ystride, z, zstride)

status = vsldconvexecx(task, y, ystride, z, zstride)

status = vslscorrexecx(task, y, ystride, z, zstride)

status = vsldcorrexecx(task, y, ystride, z, zstride)

C:

status = vslsConvExecX(task, y, ystride, z, zstride);

status = vsldConvExecX(task, y, ystride, z, zstride);

status = vslsCorrExecX(task, y, ystride, z, zstride);

status = vsldCorrExecX(task, y, ystride, z, zstride);

## Description

Each of the ExecX routines computes convolution or correlation of the data provided by the arrays x and y and then stores the results in the array z. These routines represent a special version of the operation, which assumes that the first operand vector was set on the task construction stage and the task object keeps the pointer to the array x.

Parameters of the operation are read from the task descriptor created previously by a corresponding NewTaskX constructor and pointed to by task. If task is NULL, no operation is done.

Using this form of execution routines is recommended when you need to compute multiple convolutions or correlations with the same data vector in array x against different vectors in array y. This helps improve performance by eliminating unnecessary overhead in repeated computation of intermediate data required for the operation.

## Input Parameters

Name | Type | Description
--- | --- | ---
task | FORTRAN: TYPE(VSL_CONV_TASK) for vslsconvexecx and vsldconvexecx TYPE(VSL_CORR_TASK) for vslscorrexecx and vsldcorrexecx C: VSLConvTaskPtr for vslsConvExecX and vsldConvExecX VSLCorrTaskPtr for vslsCorrExecX and vsldCorrExecX | Pointer to the task descriptor.
x ,y | FORTRAN: REAL(KIND=4), DIMENSION(*) for vslsconvexecx and vslscorrexecx REAL(KIND=8), DIMENSION(*) for vsldconvexecx and vsldcorrexecx C: float[] for vslsConvExecX and vslsCorrExecX double[] for vsldConvExeX and vsldCorrExecX | Pointer to array containing input data (for the second operand vector). See Data Allocation for more information.
ystride ,zstride | FORTRAN: INTEGER, DIMENSION(*) C: int[] | Strides for input and output data. For more information, see stride parameters.

## Output Parameters

Name | Type | Description
--- | --- | ---
z | FORTRAN: REAL(KIND=4), DIMENSION(*) for vslsconvexecx and vslscorrexecx REAL(KIND=8), DIMENSION(*) for vsldconvexecx and vsldcorrexecx C: float[] for vslsConvExecX and vslsCorrExecX double[] for vsldConvExecX and vsldCorrExecX | Pointer to the array that stores output data. See Data Allocation for more information.
status | FORTRAN: INTEGER C: int | Set to VSL_STATUS_OK if the task is executed successfully or set to non-zero error code otherwise.

Parent topic: Task Execution Routines