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:

Useful relations:

where
erfc
is the complementary error function.
where

is the cumulative normal distribution function.

where
and
and

erf-1(x)
are the inverses to 
erf(x)
, respectively.The following figure illustrates the relationships among
erf
family
functions (erf
, erfc
, cdfnorm
).erf Family Functions Relationship

Useful relations for these functions:


Argument | Result | Error Code |
---|---|---|
+ ![]() | +1 | |
- ![]() | -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 fora. See Data Types for a description of the oneMKL slice type.
- sy
- Slice selector fory. 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 ismode::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 fora. See Data Types for a description of the oneMKL slice type.
- sy
- Slice selector fory. 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 ismode::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