Developer Reference for Intel® oneAPI Math Kernel Library for C
i?amax
Finds the index of the element with maximum absolute value.
Syntax
CBLAS_INDEX cblas_isamax(const MKL_INT n, const float *x, const MKL_INT incx);
CBLAS_INDEX cblas_idamax(const MKL_INT n, const double *x, const MKL_INT incx);
CBLAS_INDEX cblas_icamax(const MKL_INT n, const void *x, const MKL_INT incx);
CBLAS_INDEX cblas_izamax(const MKL_INT n, const void *x, const MKL_INT incx);
Include Files
mkl.h
Description
Given a vector x, the cblas_i?amax functions return the index of the vector element x[i] that has the largest absolute value for real flavors, or the largest sum |Re(x[i])| + |Im(x[i])| for complex flavors.
If any of n and incx are not positive, the routine returns 0.
If more than one vector element is found with the same largest 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.
Input Parameters
- n
-
Specifies the number of elements in vector x.
- x
-
Array, size at least 1 + (n - 1) * abs(incx).
- incx
-
Specifies the increment for the elements of x.
Return Values
The index of vector element that has the largest absolute value.
BLAS 95 Interface Notes
Not applicable.