SUBROUTINE SAXPY(N,SA,SX,INCX,SY,INCY)
 
adds a scalar multiple SA of one vector SX to another vector SY.
SY := SA*SX + SY
 
N      Input, INTEGER N, number of elements in the vectors.
 
SA     Input, REAL SA, scalar multiplier.
 
SX     Input, REAL SX(N), vector.
 
INCX   Input, INTEGER INCX, increment between elements of SX.  For contiguous
       elements, INCX = 1.
 
SY     Input/output, REAL SY(N).  On input, the vector to which SA*SX
       is to be added, on output, SY:=SY+SA*SX.
 
INCY   Input, INTEGER INCY, increment between elements of SY.  For contiguous
       elements, INCY = 1.