| 270 | /******************************************************************************/ |
| 271 | |
| 272 | void daxpy ( int n, double da, double dx[], int incx, double dy[], int incy ) |
| 273 | |
| 274 | /******************************************************************************/ |
| 275 | /* |
| 276 | Purpose: |
| 277 | |
| 278 | DAXPY computes constant times a vector plus a vector. |
| 279 | |
| 280 | Discussion: |
| 281 | |
| 282 | This routine uses unrolled loops for increments equal to one. |
| 283 | |
| 284 | Modified: |
| 285 | |
| 286 | 30 March 2007 |
| 287 | |
| 288 | Author: |
| 289 | |
| 290 | FORTRAN77 original by Jack Dongarra, Cleve Moler, Jim Bunch, Pete Stewart. |
| 291 | C version by John Burkardt |
| 292 | |
| 293 | Reference: |
| 294 | |
| 295 | Jack Dongarra, Cleve Moler, Jim Bunch, Pete Stewart, |
| 296 | LINPACK User's Guide, |
| 297 | SIAM, 1979. |
| 298 | |
| 299 | Charles Lawson, Richard Hanson, David Kincaid, Fred Krogh, |
| 300 | Basic Linear Algebra Subprograms for Fortran Usage, |
| 301 | Algorithm 539, |
| 302 | ACM Transactions on Mathematical Software, |
| 303 | Volume 5, Number 3, September 1979, pages 308-323. |
| 304 | |
| 305 | Parameters: |
| 306 | |
| 307 | Input, int N, the number of elements in DX and DY. |
| 308 | |
| 309 | Input, double DA, the multiplier of DX. |
| 310 | |
| 311 | Input, double DX[*], the first vector. |
| 312 | |
| 313 | Input, int INCX, the increment between successive entries of DX. |
| 314 | |
| 315 | Input/output, double DY[*], the second vector. |
| 316 | On output, DY[*] has been replaced by DY[*] + DA * DX[*]. |
| 317 | |
| 318 | Input, int INCY, the increment between successive entries of DY. |
| 319 | */ |
| 320 | { |
| 321 | int i; |
| 322 | int ix; |
| 323 | int iy; |
| 324 | int m; |
| 325 | |
| 326 | if ( n <= 0 ) |
| 327 | { |
| 328 | return; |
| 329 | } |