NAG C Library Function Document

nag_dload (f16fbc)

1
Purpose

nag_dload (f16fbc) broadcasts a scalar into a real vector.

2
Specification

#include <nag.h>
#include <nagf16.h>
void  nag_dload (Integer n, double alpha, double x[], Integer incx, NagError *fail)

3
Description

nag_dload (f16fbc) performs the operation
x α,α,,αT ,  
where x is an n-element real vector and α is a real scalar.

4
References

Basic Linear Algebra Subprograms Technical (BLAST) Forum (2001) Basic Linear Algebra Subprograms Technical (BLAST) Forum Standard University of Tennessee, Knoxville, Tennessee http://www.netlib.org/blas/blast-forum/blas-report.pdf

5
Arguments

1:     n IntegerInput
On entry: n, the number of elements in x.
Constraint: n0.
2:     alpha doubleInput
On entry: the scalar α.
3:     x[dim] doubleOutput
Note: the dimension, dim, of the array x must be at least max1,1+n-1incx.
On exit: the scalar α is scattered with a stride of incx in x. Intermediate elements of x are unchanged.
4:     incx IntegerInput
On entry: the increment in the subscripts of x between successive elements of x.
Constraint: incx0.
5:     fail NagError *Input/Output
The NAG error argument (see Section 3.7 in How to Use the NAG Library and its Documentation).

6
Error Indicators and Warnings

NE_ALLOC_FAIL
Dynamic memory allocation failed.
See Section 2.3.1.2 in How to Use the NAG Library and its Documentation for further information.
NE_BAD_PARAM
On entry, argument value had an illegal value.
NE_INT
On entry, incx=value.
Constraint: incx0.
On entry, n=value.
Constraint: n0.
NE_NO_LICENCE
Your licence key may have expired or may not have been installed correctly.
See Section 2.7.5 in How to Use the NAG Library and its Documentation for further information.

7
Accuracy

The BLAS standard requires accurate implementations which avoid unnecessary over/underflow (see Section 2.7 of Basic Linear Algebra Subprograms Technical (BLAST) Forum (2001)).

8
Parallelism and Performance

nag_dload (f16fbc) is not threaded in any implementation.

9
Further Comments

None.

10
Example

This example initializes four elements of a real vector, x, with increment 2, with the value α=0.3.

10.1
Program Text

Program Text (f16fbce.c)

10.2
Program Data

Program Data (f16fbce.d)

10.3
Program Results

Program Results (f16fbce.r)