### MB_DDOT – Dot product of two vectors

Block SymbolLicensing group: STANDARD

Function Description
The output references yX and yY are always set to the corresponding input references uX and uY. If HLD = on then nothing is computed otherwise the BLAS function DDOT is called internally:

DDOT(N, uX, INCX, uY, INCY);

where the values N, INCX and INCY are set in the following way:

• If the input $\mathtt{\text{n}}>0$ then N is set to n else N is set to the current number of the vector or matrix elements CNTX referenced by uX.
• If the input $\mathtt{\text{incx}}\ne 0$ then INCX is set to incx else INCX is set to $1$.
• If the input $\mathtt{\text{incy}}\ne 0$ then INCY is set to incy else INCY is set to $1$.

The error flag E is set to on if:

• the reference uX or uY is not defined (i.e. input uX or uY is not connected),
• $\mathtt{\text{n}}<0$,
• $\left(\mathtt{\text{N}}-1\right)\ast \mathtt{\text{|INCX|}}+1>\mathtt{\text{CNTX}}$,
• $\left(\mathtt{\text{N}}-1\right)\ast \mathtt{\text{|INCY|}}+1>\mathtt{\text{CNTY}}$, where CNTY is a number of the vector or matrix elements referenced by uY.

See BLAS documentation [6] for more details.

Inputs

 uX Input reference to vector x Reference uY Input reference to vector y Reference n Number of processed vector elements Long (I32) incx Index increment of vector x Long (I32) incy Index increment of vector y Long (I32) HLD Hold Bool

Outputs

 yX Output reference to vector x Reference yY Output reference to vector y Reference value Return value of the function Double (F64) E Error indicator Bool

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