LAPACK 3.12.0 LAPACK: Linear Algebra PACKage
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## ◆ sscal()

 subroutine sscal ( integer n, real sa, real, dimension(*) sx, integer incx )

SSCAL

Purpose:
```    SSCAL scales a vector by a constant.
uses unrolled loops for increment equal to 1.```
Parameters
 [in] N ``` N is INTEGER number of elements in input vector(s)``` [in] SA ``` SA is REAL On entry, SA specifies the scalar alpha.``` [in,out] SX ` SX is REAL array, dimension ( 1 + ( N - 1 )*abs( INCX ) )` [in] INCX ``` INCX is INTEGER storage spacing between elements of SX```
Further Details:
```     jack dongarra, linpack, 3/11/78.
modified 3/93 to return if incx .le. 0.
modified 12/3/93, array(1) declarations changed to array(*)```

Definition at line 78 of file sscal.f.

79*
80* -- Reference BLAS level1 routine --
81* -- Reference BLAS is a software package provided by Univ. of Tennessee, --
82* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
83*
84* .. Scalar Arguments ..
85 REAL SA
86 INTEGER INCX,N
87* ..
88* .. Array Arguments ..
89 REAL SX(*)
90* ..
91*
92* =====================================================================
93*
94* .. Local Scalars ..
95 INTEGER I,M,MP1,NINCX
96* ..
97* .. Parameters ..
98 REAL ONE
99 parameter(one=1.0e+0)
100* ..
101* .. Intrinsic Functions ..
102 INTRINSIC mod
103* ..
104 IF (n.LE.0 .OR. incx.LE.0 .OR. sa.EQ.one) RETURN
105 IF (incx.EQ.1) THEN
106*
107* code for increment equal to 1
108*
109*
110* clean-up loop
111*
112 m = mod(n,5)
113 IF (m.NE.0) THEN
114 DO i = 1,m
115 sx(i) = sa*sx(i)
116 END DO
117 IF (n.LT.5) RETURN
118 END IF
119 mp1 = m + 1
120 DO i = mp1,n,5
121 sx(i) = sa*sx(i)
122 sx(i+1) = sa*sx(i+1)
123 sx(i+2) = sa*sx(i+2)
124 sx(i+3) = sa*sx(i+3)
125 sx(i+4) = sa*sx(i+4)
126 END DO
127 ELSE
128*
129* code for increment not equal to 1
130*
131 nincx = n*incx
132 DO i = 1,nincx,incx
133 sx(i) = sa*sx(i)
134 END DO
135 END IF
136 RETURN
137*
138* End of SSCAL
139*