Visible to Intel only — GUID: GUID-37592AC2-01E4-4209-B582-BF29B7ECAFB4
Visible to Intel only — GUID: GUID-37592AC2-01E4-4209-B582-BF29B7ECAFB4
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:
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/A90EC24B-2ED2-4996-A5FF-19C6CC818D59-low.png)
Useful relations:
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/BE2B9A16-0C5C-4109-9616-4BAEC9594776-low.png)
where erfc is the complementary error function.
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/149EF2D6-CC15-440F-8E87-1E6D13CE85BA-low.png)
where
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/93FB610B-5472-4BD4-A34D-9493B6B68FE9-low.png)
is the cumulative normal distribution function.
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/30149249-4516-4FF2-A2BF-153D6426EA6B-low.png)
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).
![erf Family Functions Relationship](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/93677649-F584-4617-A9E0-BF40C83276CE-low.png)
Useful relations for these functions:
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/1EEC3772-FF08-4608-B4F9-E0A9D74BBDBD-low.png)
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/23164C6F-E757-4A59-8DDE-8A5BCEAAF909-low.png)
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 |
---|---|
sycl::half |
GPU |
_Float16 |
CPU |
float |
CPU and GPU |
double |
CPU and GPU |
Input Parameters
Buffer API
- exec_queue
-
The queue where the routine will 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 will 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:
share/doc/mkl/examples/sycl/vml/source/verf.cpp