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| 2 | 1 | equemene | <HEAD>
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| 3 | 1 | equemene | <TITLE>HPL_daxpy HPL 2.0 Library Functions September 10, 2008</TITLE> |
| 4 | 1 | equemene | </HEAD>
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| 5 | 1 | equemene | |
| 6 | 1 | equemene | <BODY BGCOLOR="WHITE" TEXT = "#000000" LINK = "#0000ff" VLINK = "#000099" |
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| 8 | 1 | equemene | |
| 9 | 1 | equemene | <H1>Name</H1> |
| 10 | 1 | equemene | <B>HPL_daxpy</B> y := y + alpha * x. |
| 11 | 1 | equemene | |
| 12 | 1 | equemene | <H1>Synopsis</H1> |
| 13 | 1 | equemene | <CODE>#include "hpl.h"</CODE><BR><BR> |
| 14 | 1 | equemene | <CODE>void</CODE> |
| 15 | 1 | equemene | <CODE>HPL_daxpy(</CODE> |
| 16 | 1 | equemene | <CODE>const int</CODE> |
| 17 | 1 | equemene | <CODE>N</CODE>, |
| 18 | 1 | equemene | <CODE>const double</CODE> |
| 19 | 1 | equemene | <CODE>ALPHA</CODE>, |
| 20 | 1 | equemene | <CODE>const double *</CODE> |
| 21 | 1 | equemene | <CODE>X</CODE>, |
| 22 | 1 | equemene | <CODE>const int</CODE> |
| 23 | 1 | equemene | <CODE>INCX</CODE>, |
| 24 | 1 | equemene | <CODE>double *</CODE> |
| 25 | 1 | equemene | <CODE>Y</CODE>, |
| 26 | 1 | equemene | <CODE>const int</CODE> |
| 27 | 1 | equemene | <CODE>INCY</CODE> |
| 28 | 1 | equemene | <CODE>);</CODE> |
| 29 | 1 | equemene | |
| 30 | 1 | equemene | <H1>Description</H1> |
| 31 | 1 | equemene | <B>HPL_daxpy</B> |
| 32 | 1 | equemene | scales the vector x by alpha and adds it to y. |
| 33 | 1 | equemene | |
| 34 | 1 | equemene | <H1>Arguments</H1> |
| 35 | 1 | equemene | <PRE>
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| 36 | 1 | equemene | N (local input) const int |
| 37 | 1 | equemene | On entry, N specifies the length of the vectors x and y. N |
| 38 | 1 | equemene | must be at least zero. |
| 39 | 1 | equemene | </PRE>
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| 40 | 1 | equemene | <PRE>
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| 41 | 1 | equemene | ALPHA (local input) const double |
| 42 | 1 | equemene | On entry, ALPHA specifies the scalar alpha. When ALPHA is |
| 43 | 1 | equemene | supplied as zero, then the entries of the incremented array X |
| 44 | 1 | equemene | need not be set on input. |
| 45 | 1 | equemene | </PRE>
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| 46 | 1 | equemene | <PRE>
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| 47 | 1 | equemene | X (local input) const double * |
| 48 | 1 | equemene | On entry, X is an incremented array of dimension at least |
| 49 | 1 | equemene | ( 1 + ( n - 1 ) * abs( INCX ) ) that contains the vector x. |
| 50 | 1 | equemene | </PRE>
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| 51 | 1 | equemene | <PRE>
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| 52 | 1 | equemene | INCX (local input) const int |
| 53 | 1 | equemene | On entry, INCX specifies the increment for the elements of X. |
| 54 | 1 | equemene | INCX must not be zero. |
| 55 | 1 | equemene | </PRE>
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| 56 | 1 | equemene | <PRE>
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| 57 | 1 | equemene | Y (local input/output) double * |
| 58 | 1 | equemene | On entry, Y is an incremented array of dimension at least |
| 59 | 1 | equemene | ( 1 + ( n - 1 ) * abs( INCY ) ) that contains the vector y. |
| 60 | 1 | equemene | On exit, the entries of the incremented array Y are updated |
| 61 | 1 | equemene | with the scaled entries of the incremented array X. |
| 62 | 1 | equemene | </PRE>
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| 63 | 1 | equemene | <PRE>
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| 64 | 1 | equemene | INCY (local input) const int |
| 65 | 1 | equemene | On entry, INCY specifies the increment for the elements of Y. |
| 66 | 1 | equemene | INCY must not be zero. |
| 67 | 1 | equemene | </PRE>
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| 68 | 1 | equemene | |
| 69 | 1 | equemene | <H1>Example</H1> |
| 70 | 1 | equemene | <CODE>#include "hpl.h"</CODE><BR><BR> |
| 71 | 1 | equemene | <PRE>
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| 72 | 1 | equemene | int main(int argc, char *argv[]) |
| 73 | 1 | equemene | {
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| 74 | 1 | equemene | double x[3], y[3]; |
| 75 | 1 | equemene | x[0] = 1.0; x[1] = 2.0; x[2] = 3.0; |
| 76 | 1 | equemene | y[0] = 4.0; y[1] = 5.0; y[2] = 6.0; |
| 77 | 1 | equemene | HPL_daxpy( 3, 2.0, x, 1, y, 1 ); |
| 78 | 1 | equemene | printf("y=[%f,%f,%f]\n", y[0], y[1], y[2]);
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| 79 | 1 | equemene | exit(0); return(0); |
| 80 | 1 | equemene | } |
| 81 | 1 | equemene | </PRE>
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| 82 | 1 | equemene | |
| 83 | 1 | equemene | <H1>See Also</H1> |
| 84 | 1 | equemene | <A HREF="HPL_dcopy.html">HPL_dcopy</A>, |
| 85 | 1 | equemene | <A HREF="HPL_dscal.html">HPL_dscal</A>, |
| 86 | 1 | equemene | <A HREF="HPL_dswap.html">HPL_dswap</A>. |
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| 88 | 1 | equemene | </BODY>
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| 89 | 1 | equemene | </HTML> |