iamin#
Finds the index of the element with the smallest absolute value.
Description
The iamin
routines return an index i
such that x[i]
has
the minimum absolute value of all elements in vector x
(real
variants), or such that (|Re(x[i]
)| + |Im(x[i]
)|) is minimal
(complex variants).
The index is zero-based if base
is set to oneapi::math::index_base::zero
(default)
or one-based if it is set to oneapi::math::index_base::one
.
If either n
or incx
is not positive, the routine returns
0
, regardless of the base of the index selected.
If more than one vector element is found with the same smallest absolute value, the index of the first one encountered is returned.
If the vector contains NaN
values, then the routine returns the
index of the first NaN
.
iamin
supports the following precisions.
T
float
double
std::complex<float>
std::complex<double>
iamin (Buffer Version)#
Syntax
namespace oneapi::math::blas::column_major {
void iamin(sycl::queue &queue,
std::int64_t n,
sycl::buffer<T,1> &x,
std::int64_t incx,
sycl::buffer<std::int64_t,1> &result,
oneapi::math::index_base base = oneapi::math::index_base::zero)
}
namespace oneapi::math::blas::row_major {
void iamin(sycl::queue &queue,
std::int64_t n,
sycl::buffer<T,1> &x,
std::int64_t incx,
sycl::buffer<std::int64_t,1> &result,
oneapi::math::index_base base = oneapi::math::index_base::zero)
}
Input Parameters
- queue
The queue where the routine should be executed.
- n
Number of elements in vector
x
.- x
Buffer holding input vector
x
. The buffer must be of size at least (1 + (n
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector x.
- base
Indicates how the output value is indexed. If omitted, defaults to zero-based indexing.
Output Parameters
- result
Buffer where the index
i
of the minimum element will be stored.
Throws
This routine shall throw the following exceptions if the associated condition is detected. An implementation may throw additional implementation-specific exception(s) in case of error conditions not covered here.
oneapi::math::invalid_argument
oneapi::math::unsupported_device
iamin (USM Version)#
Syntax
namespace oneapi::math::blas::column_major {
sycl::event iamin(sycl::queue &queue,
std::int64_t n,
const T *x,
std::int64_t incx,
std::int64_t *result,
oneapi::math::index_base base = oneapi::math::index_base::zero,
const std::vector<sycl::event> &dependencies = {})
}
namespace oneapi::math::blas::row_major {
sycl::event iamin(sycl::queue &queue,
std::int64_t n,
const T *x,
std::int64_t incx,
std::int64_t *result,
oneapi::math::index_base base = oneapi::math::index_base::zero,
const std::vector<sycl::event> &dependencies = {})
}
Input Parameters
- queue
The queue where the routine should be executed.
- n
Number of elements in vector
x
.- x
The pointer to input vector
x
. The array holding input vectorx
must be of size at least (1 + (n
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector x.
- base
Indicates how the output value is indexed. If omitted, defaults to zero-based indexing.
- dependencies
List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.
Output Parameters
- result
Pointer to where the index
i
of the minimum element will be stored.
Return Values
Output event to wait on to ensure computation is complete.
Throws
This routine shall throw the following exceptions if the associated condition is detected. An implementation may throw additional implementation-specific exception(s) in case of error conditions not covered here.
oneapi::math::invalid_argument
oneapi::math::unsupported_device
oneapi::math::device_bad_alloc
Parent topic: BLAS Level 1 Routines