next up previous contents
Next: Maximum Absolute Value in Up: Norms of Vectors Previous: PLAPACK FORTRAN-C interface

PLAPACK calls

The PLAPACK calling sequences are given by place HR here

figure6553

figure6557

figure6560

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 x and alpha. Instead of returning the result as the function value, it is returned in alpha.

Local call:

When a node calls PLA_Local_nrm2 or PLA_Local_asum, the operation is equivalent to extracting the local information (data type, length, and pointer to the buffers) and locally performing the appropriate operation. The local dimensions of alpha must be tex2html_wrap_inline13941 , but it can be of any object type. The local dimensions of x 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_Nrm2 or PLA_Asum, which performs the BLAS call on the distributed objects. Parameter alpha must be a tex2html_wrap_inline13943 multiscalars. Parameter x must be of object type vector or (duplicated) projected vector. The global dimensions of the different objects must be such that the operation is well-defined.


next up previous contents
Next: Maximum Absolute Value in Up: Norms of Vectors Previous: PLAPACK FORTRAN-C interface

rvdg@cs.utexas.edu