### ML_DLANGE – Computes one of the matrix norms of a general matrix

Block SymbolLicensing group: STANDARD

Function Description
The output references yA and yWORK are always set to the corresponding input references uA and uWORK. If HLD = on then nothing is computed otherwise the LAPACK function DLANGE is called internally:

value = DLANGE(sNORM, M, N, uA, LDA, uWORK;

where parameters of DLACPY are set in the following way:

• Integer input norm is mapped to the string sNORM: $\left\{0,1\right\}\to \mathtt{\text{"F"}}$ (Frobenius norm), $\left\{2\right\}\to \mathtt{\text{"M"}}$ (max(abs(A(i,j)))), $\left\{3\right\}\to \mathtt{\text{"1"}}$ (one norm) and $\left\{4\right\}\to \mathtt{\text{"I"}}$ (infinity norm).
• 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 the matrix referenced by uA.
• uWORK is the working vector of dimension $\mathtt{\text{LWORK}}\ge \mathtt{\text{M}}$. uWORK is used only for infinity norm, otherwise it is not referenced.

The error flag E is set to on if:

• the reference uA is not defined (i.e. input uA is not connected),
• the reference uWORK is not defined for $\mathtt{\text{norm}}=4$ (i.e. input uWORK is not connected).

See LAPACK documentation [7] for more details.
Use the block MB_DNRM2 for computation of Frobenius norm of a vector.

Inputs

 uA Input reference to matrix A Reference uWORK Input reference to working vector WORK Reference norm The selected matrix norm  $↓$0 $↑$4 $\odot$0.00E+00 Long (I32) HLD Hold Bool

Outputs

 yA Output reference to matrix A Reference yWORK Output reference to working vector WORK Reference value Return value of the function Double (F64) E Error indicator Bool

2020 © REX Controls s.r.o., www.rexygen.com