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).

If either n or incx are not positive, the routine returns 0.

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>

Note

The index is zero-based.

iamin (Buffer Version)

Syntax

namespace oneapi::mkl::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)
}
namespace oneapi::mkl::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)
}

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.

Output Parameters

result

Buffer where the zero-based 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::mkl::invalid_argument

oneapi::mkl::unsupported_device

oneapi::mkl::host_bad_alloc

oneapi::mkl::device_bad_alloc

oneapi::mkl::unimplemented

iamin (USM Version)

Syntax

namespace oneapi::mkl::blas::column_major {
    sycl::event iamin(sycl::queue &queue,
                      std::int64_t n,
                      const T *x,
                      std::int64_t incx,
                      T_res *result,
                      const std::vector<sycl::event> &dependencies = {})
}
namespace oneapi::mkl::blas::row_major {
    sycl::event iamin(sycl::queue &queue,
                      std::int64_t n,
                      const T *x,
                      std::int64_t incx,
                      T_res *result,
                      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 vector x must be of size at least (1 + (n - 1)*abs(incx)). See Matrix Storage for more details.

incx

Stride of vector x.

Output Parameters

result

Pointer to where the zero-based 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::mkl::invalid_argument

oneapi::mkl::unsupported_device

oneapi::mkl::host_bad_alloc

oneapi::mkl::device_bad_alloc

oneapi::mkl::unimplemented

Parent topic: BLAS Level 1 Routines