### MB_DNRM2 – Euclidean norm of a vector

Block SymbolLicensing group: STANDARD

Function Description
The output reference yX is always set to the input reference uX. If HLD = on then nothing is computed otherwise the BLAS function DNRM2 is called internally:

value = DNRM2(N, uX, INCX);

where the values N and INCX 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 CNT referenced by uX.
• If the input $\mathtt{\text{incx}}>0$ then INCX is set to incx else INCX is set to $1$.

The error flag E is set to on if:

• the reference uX is not defined (i.e. input uX is not connected),
• $\mathtt{\text{n}}<0$ or $\mathtt{\text{incx}}<0$,
• $\left(\mathtt{\text{N}}-1\right)\ast \mathtt{\text{|INCX|}}+1>\mathtt{\text{CNT}}$.

See BLAS documentation [6] for more details.

Use the block ML_DLANGE for computation of various norms of a matrix.

Inputs

 uX Input reference to vector x Reference n Number of processed vector elements  $\odot$0.00E+00 Long(I32) incx Index increment of vector x  $\odot$0.00E+00 Long(I32) HLD Hold Bool

Outputs

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

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