Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
?dotc
Computes a dot product of a conjugated vector with another vector.
Syntax
res = cdotc(n, x, incx, y, incy)
res = zdotc(n, x, incx, y, incy)
res = dotc(x, y)
Include Files
mkl.fi, mkl_blas.f90
Description
The ?dotc routines perform a vector-vector operation defined as:
\[\sum_{i=1}^n \mathrm{conjg}(x_i) \, y_i \,, \]
where \(x_i\) and \(y_i\) are elements of vectors x and y.
Input Parameters
- n
-
INTEGER. Specifies the number of elements in vectors x and y.
- x
-
COMPLEX array for cdotc
DOUBLE COMPLEX array for zdotc
The size is at least 1 + (n - 1) * abs(incx).
- incx
-
INTEGER. Specifies the increment for the elements of x.
- y
-
COMPLEX array for cdotc
DOUBLE COMPLEX array for zdotc
The size is at least 1 + (n - 1) * abs(incy).
- incy
-
INTEGER. Specifies the increment for the elements of y.
Return Values
- res
-
COMPLEX for cdotc
DOUBLE COMPLEX for zdotc
Contains the result of the dot product of the conjugated x and unconjugated y, if n is positive. Otherwise, it contains 0.
BLAS 95 Interface Notes
Routines in Fortran 95 interface have fewer arguments in the calling sequence than their FORTRAN 77 counterparts. For general conventions applied to skip redundant or reconstructible arguments, see BLAS 95 Interface Conventions.
Specific details for the routine dotc interface are the following:
- x
-
Holds the vector with the number of elements n.
- y
-
Holds the vector with the number of elements n.