dasumf.f

double precision function dasumf(n,dx,incx)
c
c takes the sum of the absolute values.
c jack dongarra, linpack, 3/11/78.
c modified 3/93 to return if incx .le. 0.
c modified 12/3/93, array(1) declarations changed to array(*)
c
double precision dx(*),dtemp
integer i,incx,m,mp1,n,nincx
c
 dasumf =0.0d0
 dtemp =0.0d0
if( n.le.0.or. incx.le.0 )return
if(incx.eq.1)go to20
c
c code for increment not equal to 1
c
 nincx = n*incx
do10 i =1,nincx,incx
 dtemp = dtemp + dabs(dx(i))
10continue
 dasumf = dtemp
return
c
c code for increment equal to 1
c
c
c clean-up loop
c
20 m =mod(n,6)
if( m .eq.0 ) go to40
do30 i =1,m
 dtemp = dtemp + dabs(dx(i))
30continue
if( n .lt.6 ) go to60
40 mp1 = m +1
do50 i = mp1,n,6
 dtemp = dtemp + dabs(dx(i)) + dabs(dx(i +1)) + dabs(dx(i +2))
*+ dabs(dx(i +3)) + dabs(dx(i +4)) + dabs(dx(i +5))
50continue
60 dasumf = dtemp
return
 end