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