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iamin

Finds the index of the element with the smallest absolute value in a vector

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).

iamin supports the following precisions:

T

float

double

std::complex<float>

std::complex<double>

Note

The index is zero-based.

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 (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. Size of the buffer must be 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 is stored.

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. Size of the array holding input vector x must be 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 is stored.

Return Values

Output event to wait on to ensure computation is complete.

iamax nrm2