### MB_DGEMV – Performs y := alpha*A*x + beta*y or y := alpha*A^T*x + beta*y

Block SymbolLicensing group: STANDARD

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

DGEMV(sTRANS, M, N, alpha, uA, LDA, uX, INCX, beta, uY, INCY);

where parameters of DGEMV are set in the following way:

• Integer input trans is mapped to the string sTRANS: $\left\{0,1\right\}\to \mathtt{\text{"N"}}$, $\left\{2\right\}\to \mathtt{\text{"T"}}$ and $\left\{3\right\}\to \mathtt{\text{"C"}}$.
• M is number of rows of the matrix referenced by uA.
• N is number of columns of the matrix referenced by uA.
• LDA is the leading dimension of matrix referenced by uA.
• 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 uA or uX or uY is not defined (i.e. input uA or uX or uY is not connected),
• trans is less than 0 or greater than 3
• the call of the function DGEMV returns error using the function XERBLA, see the system log.

See BLAS documentation [6] for more details.

Inputs

 uA Input reference to matrix A Reference uX Input reference to vector x Reference uY Input reference to vector y Reference trans Transposition of the input matrix  $↓$0 $↑$3 $\odot$0.00E+00 Long (I32) incx Index increment of vector x  $\odot$0.00E+00 Long(I32) incy Index increment of vector y  $\odot$0.00E+00 Long(I32) alpha Scalar coefficient alpha  $\odot$0.0 Double (F64) beta Scalar coefficient beta Double (F64) HLD Hold Bool

Outputs

 yA Output reference to matrix A Reference yX Output reference to vector x Reference yY Output reference to vector y Reference E Error indicator Bool

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