Intel® oneAPI Math Kernel Library (oneMKL) - Data Parallel C++ Developer Reference

Developer Reference

Contents

erf

Computes the element-wise error function of vector elements.

Description

The
erf
 function computes the error function values for elements of the input vector
a
 and writes them to the output vector
y
.
The error function is defined as given by:
LaTex Math image.
Useful relations:
LaTex Math image.
where
erfc
 is the complementary error function.
LaTex Math image.
where
LaTex Math image.
is the cumulative normal distribution function.
LaTex Math image.
where LaTex Math image. and
erf-1(x)
 are the inverses to LaTex Math image. and
erf(x)
, respectively.
The following figure illustrates the relationships among
erf
 family functions (
erf
,
erfc
,
cdfnorm
).
erf Family Functions Relationship
erf Family Functions Relationship
Useful relations for these functions:
LaTex Math image.
LaTex Math image.
Argument
Result
Error Code
+LaTex Math image.
+1
-LaTex Math image.
-1
QNAN
QNAN
SNAN
QNAN

API

Syntax
Buffer API
namespace oneapi::mkl::vm {

sycl::event erf(sycl::queue & exec_queue,
      std::int64_t n,
      sycl::buffer<T> & a,
      sycl::buffer<T> & y,
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}
namespace oneapi::mkl::vm {

sycl::event erf(sycl::queue & exec_queue,
      sycl::buffer<T> & a,
      oneapi::mkl::slice sa,
      sycl::buffer<T> & y,
      oneapi::mkl::slice sy,
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}
USM API
namespace oneapi::mkl::vm {

sycl::event erf(sycl::queue & exec_queue,
      std::int64_t n,
      T const * a,
      T * y,
      std::vector<sycl::event> const & depends = {},
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}
namespace oneapi::mkl::vm {

sycl::event erf(sycl::queue & exec_queue,
      T const * a,
      oneapi::mkl::slice sa,
      T * y,
      oneapi::mkl::slice sy,
      std::vector<sycl::event> const & depends = {},
      oneapi::mkl::vm::mode mode = oneapi::mkl::vm::mode::not_defined);

}
erf
 supports the following precisions and devices:
T
Devices supported
float
CPU and GPU
double
CPU and GPU
Input Parameters
Buffer API
exec_queue
The queue where the routine should be executed.
n
Specifies the number of elements to be calculated.
a
The buffer containing the input vector.
sa
Slice selector for
a
. See Data Types for a description of the oneMKL slice type.
sy
Slice selector for
y
. See Data Types for a description of the oneMKL slice type.
mode
Overrides the global VM mode setting for this function call. See the set_mode function for possible values and their description. This is an optional parameter. The default value is
mode::not_defined
.
USM API
exec_queue
The queue where the routine should be executed.
n
Specifies the number of elements to be calculated.
a
Pointer to the input vector.
sa
Slice selector for
a
. See Data Types for a description of the oneMKL slice type.
sy
Slice selector for
y
. See Data Types for a description of the oneMKL slice type.
depends
Vector of dependent events (to wait for input data to be ready). This is an optional parameter. The default is an empty vector.
mode
Overrides the global VM mode setting for this function call. See the set_mode function for possible values and their description. This is an optional parameter. The default value is
mode::not_defined
.
Output Parameters
Buffer API
y
The buffer containing the output vector.
return value (event)
Computation end event.
USM API
y
Pointer to the output vector.
return value (event)
Computation end event.

Examples

An example of how to use
erf
 can be found in the oneMKL installation directory, under:
examples/dpcpp/vml/source/verf.cpp

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.