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.TH HPL_dger 3 "September 10, 2008" "HPL 2.0" "HPL Library Functions"
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.SH NAME
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HPL_dger \- A := alpha * x * y^T + A.
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.SH SYNOPSIS
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\fB\&#include "hpl.h"\fR
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\fB\&void\fR
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\fB\&HPL_dger(\fR
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\fB\&const enum HPL_ORDER\fR
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\fI\&ORDER\fR,
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\fB\&const int\fR
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\fI\&M\fR,
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\fB\&const int\fR
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\fI\&N\fR,
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\fB\&const double\fR
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\fI\&ALPHA\fR,
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\fB\&const double *\fR
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\fI\&X\fR,
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\fB\&const int\fR
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\fI\&INCX\fR,
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\fB\&double *\fR
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\fI\&Y\fR,
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\fB\&const int\fR
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\fI\&INCY\fR,
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\fB\&double *\fR
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\fI\&A\fR,
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\fB\&const int\fR
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\fI\&LDA\fR
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\fB\&);\fR
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.SH DESCRIPTION
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\fB\&HPL_dger\fR
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performs the rank 1 operation
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    A := alpha * x * y^T + A,
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where alpha is a scalar,  x is an m-element vector, y is an n-element
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vector and A is an m by n matrix.
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.SH ARGUMENTS
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.TP 8
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ORDER   (local input)           const enum HPL_ORDER
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On entry, ORDER  specifies the storage format of the operands
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as follows:
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   ORDER = HplRowMajor,
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   ORDER = HplColumnMajor.
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.TP 8
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M       (local input)           const int
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On entry,  M  specifies  the number of rows of  the matrix A.
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M must be at least zero.
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.TP 8
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N       (local input)           const int
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On entry, N  specifies the number of columns of the matrix A.
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N must be at least zero.
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.TP 8
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ALPHA   (local input)           const double
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On entry, ALPHA specifies the scalar alpha.   When  ALPHA  is
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supplied as zero then  X and Y  need not be set on input.
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.TP 8
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X       (local input)           const double *
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On entry,  X  is an incremented array of dimension  at  least
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( 1 + ( m - 1 ) * abs( INCX ) )  that  contains the vector x.
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.TP 8
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INCX    (local input)           const int
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On entry, INCX specifies the increment for the elements of X.
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INCX must not be zero.
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.TP 8
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Y       (local input)           double *
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On entry,  Y  is an incremented array of dimension  at  least
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( 1 + ( n - 1 ) * abs( INCY ) )  that  contains the vector y.
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.TP 8
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INCY    (local input)           const int
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On entry, INCY specifies the increment for the elements of Y.
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INCY must not be zero.
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.TP 8
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A       (local input/output)    double *
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On entry,  A  points  to an array of size equal to or greater
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than LDA * n.  Before  entry, the leading m by n part  of the
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array  A  must contain the matrix coefficients. On exit, A is
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overwritten by the updated matrix.
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.TP 8
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LDA     (local input)           const int
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On entry,  LDA  specifies  the  leading  dimension  of  A  as
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declared  in  the  calling  (sub) program.  LDA  must  be  at
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least MAX(1,m).
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.SH EXAMPLE
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\fI\&#include "hpl.h"\fR
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int main(int argc, char *argv[])
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.br
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{
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.br
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   double a[2*2], x[2], y[2];
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.br
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   a[0] = 1.0; a[1] = 2.0; a[2] = 3.0; a[3] = 3.0;
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.br
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   x[0] = 2.0; x[1] = 1.0; y[2] = 1.0; y[3] = 2.0;
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.br
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   HPL_dger( HplColumnMajor, 2, 2, 2.0, x, 1, y, 1,
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.br
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             a, 2 );
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.br
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   printf("y=[%f,%f]\en", y[0], y[1]);
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.br
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   exit(0); return(0);
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.br
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}
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.SH SEE ALSO
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.BR HPL_dgemv \ (3),
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.BR HPL_dtrsv \ (3).