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PLAPACK calls

For the triangular matrix-vector multiply, the calling sequences are given by place HR here

figure7897

figure7901

figure7904

place HR here Parameters UPLO, TRANS, and DIAG have been replaced by integer parameters uplo, trans, and diag, which can take on the values indicated in Table gif. All other parameters are now passed as part of linear algebra objects a and x

Local call:

When a node calls PLA_Local_trmv, the operation is equivalent to extracting the local information (datatype, dimensions, and pointer to the buffer) and locally performing a triangular matrix-vector multiply. The local dimension of a and x must be such that the operation is well-defined. The local matrix associated with a must be lower triangular. All objects must have the same datatype. Notice: no communication is performed as part of this call. Thus, all information must be locally available.

Global call:

All nodes must simultaneously call PLA_Trmv, which performs the BLAS call on the distributed objects. Parameters uplo, trans, and diag still have the same meaning. Parameter a must be an object of type matrix and x of type vector, projected vector, or duplicated projected vector. The global dimensions of the different objects must be such that the operation is well-defined.


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Next: Triangular Solve Up: Triangular Matrix-Vector Multiplication Previous: PLAPACK FORTRAN-C interface

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