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psb_gedot -- Dot Product

This function computes dot product between two vectors $x$ and $y$.
If $x$ and $y$ are real vectors it computes dot-product as:

\begin{displaymath}dot \leftarrow x^T y\end{displaymath}

Else if $x$ and $y$ are complex vectors then it computes dot-product as:

\begin{displaymath}dot \leftarrow x^H y\end{displaymath}

psb_gedot(x, y, desc_a, info)

Table 2: Data types
$dot$, $x$, $y$ Function
Short Precision Real psb_gedot
Long Precision Real psb_gedot
Short Precision Complex psb_gedot
Long Precision Complex psb_gedot


Type:
Synchronous.
On Entry
x
the local portion of global dense matrix $x$.
Scope: local
Type: required
Intent: in.
Specified as: an array of rank one or two containing numbers of type specified in Table 2. The rank of $x$ must be the same of $y$.
y
the local portion of global dense matrix $y$.
Scope: local
Type: required
Intent: in.
Specified as: an array of rank one or two containing numbers of type specified in Table 2. The rank of $y$ must be the same of $x$.
desc_a
contains data structures for communications.
Scope: local
Type: required
Intent: in.
Specified as: a structured data of type descdatapsb_desc_type.

On Return
Function value
is the dot product of subvectors $x$ and $y$.
Scope: global
Specified as: a number of the data type indicated in Table 2.
info
Error code.
Scope: local
Type: required
Intent: out.
An integer value; 0 means no error has been detected.


next up previous contents
Next: psb_gedots Generalized Up: Computational routines Previous: psb_geaxpby General   Contents