Visible to Intel only — GUID: GUID-2A53F402-7BAD-443F-8CFA-62B190E2839E
Visible to Intel only — GUID: GUID-2A53F402-7BAD-443F-8CFA-62B190E2839E
erfc
Computes the element-wise complementary error function of vector elements.
Description
The erfc function computes the complementary error function values for elements of the input vector a and writes them to the output vector y.
The complementary error function is defined as follows:
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/38CC035E-B5C1-42D3-8F80-BB72BDAEE726-low.png)
Useful relations:
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/7D5A3140-94B6-446F-B6E3-A6CBD3DD418D-low.png)
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/1D20339E-EABE-4DAF-BBC2-99B8638B5578-low.png)
where
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/ECFCD118-FD78-4B7E-B4E3-C29C8A400F38-low.png)
is the cumulative normal distribution function.
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/832156EF-6408-45BC-97CE-CFA26C7DD5D6-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).
![erfc Family Functions Relationship](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/1CAA8CF7-C128-4AAE-AD9E-2F193530EADD-low.png)
Useful relations for these functions:
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/38BD9D18-D9E5-410B-A116-88FF8B6FCF8B-low.png)
![](/content/dam/docs/us/en/developer-reference-dpcpp/2024-2/1D425EFE-1376-407C-9621-064A3A06CB49-low.png)
Argument |
Result |
Error Code |
---|---|---|
a > underflow |
+0 |
status::underflow |
+ |
+0 |
|
- |
+2 |
|
QNAN |
QNAN |
|
SNAN |
QNAN |
API
Syntax
Buffer API
namespace oneapi::mkl::vm {
sycl::event erfc(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,
oneapi::mkl::vm::error_handler<T> errhandler = {});
}
namespace oneapi::mkl::vm {
sycl::event erfc(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,
oneapi::mkl::vm::error_handler<T> errhandler = {});
}
USM API
namespace oneapi::mkl::vm {
sycl::event erfc(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,
oneapi::mkl::vm::error_handler<T> errhandler = {});
}
namespace oneapi::mkl::vm {
sycl::event erfc(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,
oneapi::mkl::vm::error_handler<T> errhandler = {});
}
erfc 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.
- errhandler
-
Sets local error handling mode for this function call. See the create_error_handler function for arguments and their descriptions. This is an optional parameter. The local error handler is disabled by default.
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.
- errhandler
-
Sets local error handling mode for this function call. See the ref:create_error_handler function for arguments and their descriptions. This is an optional parameter. The local error handler is disabled by default.
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 erfc can be found in the oneMKL installation directory, under:
share/doc/mkl/examples/sycl/vml/source/verfc.cpp