37 lines
918 B
Fortran
37 lines
918 B
Fortran
double complex function zdotcf(n,zx,incx,zy,incy)
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c
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c forms the dot product of a vector.
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c jack dongarra, 3/11/78.
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c modified 12/3/93, array(1) declarations changed to array(*)
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c
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double complex zx(*),zy(*),ztemp
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integer i,incx,incy,ix,iy,n
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ztemp = (0.0d0,0.0d0)
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zdotcf = (0.0d0,0.0d0)
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if(n.le.0)return
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if(incx.eq.1.and.incy.eq.1)go to 20
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c
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c code for unequal increments or equal increments
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c not equal to 1
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c
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ix = 1
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iy = 1
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if(incx.lt.0)ix = (-n+1)*incx + 1
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if(incy.lt.0)iy = (-n+1)*incy + 1
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do 10 i = 1,n
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ztemp = ztemp + dconjg(zx(ix))*zy(iy)
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ix = ix + incx
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iy = iy + incy
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10 continue
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zdotcf = ztemp
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return
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c
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c code for both increments equal to 1
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c
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20 do 30 i = 1,n
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ztemp = ztemp + dconjg(zx(i))*zy(i)
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30 continue
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zdotcf = ztemp
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return
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end
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