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PLAPACK calls

The PLAPACK calling sequences for adding a scaled object to another object are place HR here

figure6466

figure6470

figure6473

place HR here The data type of the operands and parameters like vector length and stride are now passed as part of linear algebra objects alpha, x and y.

Local call:

When a node calls PLA_Local_axpy, the operation is equivalent to extracting the local information (data type, length, and pointer to the buffers) and locally performing the axpy. The object type can by any valid PLAPACK object type: the local axpy can also be used ``axpy'' two dimensional objects, like multiscalars, (duplicated) (projected) multivectors, and matrices. The local dimensions of alpha must be tex2html_wrap_inline13843 , but it can be of any object type. The local dimensions of x, and y must be such that the operation is well-defined. All objects must have the same data type. 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_Axpy, which performs the BLAS call on the distributed objects. Parameter alpha must be a tex2html_wrap_inline13845 multiscalar. Parameters x and y can be of any object type. The global dimensions of the different objects must be such that the operation is well-defined.


next up previous contents
Next: Inner Product of Vectors Up: Scaled Vector (Object) Addition Previous: PLAPACK FORTRAN-C interface

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