43 lines
1.0 KiB
Fortran
43 lines
1.0 KiB
Fortran
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!
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! project "gravity field"
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!
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!-----------------------------------------------------------------------
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module realfield
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implicit none
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!-----------------------------------------------------------------------
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type massbody
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real :: posx, posy
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real :: mass
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integer :: serial
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end type
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!-----------------------------------------------------------------------
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contains
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function compute_gravity(ix, iy, body)
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integer, intent(in) :: ix, iy
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type(massbody), intent(in) :: body
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real :: compute_gravity
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real :: rx, ry, dist
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rx = real(ix) - body%posx
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ry = real(iy) - body%posy
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dist = sqrt( (rx*rx) + (ry*ry) )
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if (dist .LT. 0.15) then
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write (0, *) "dist too small ", dist
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compute_gravity = 0e0
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endif
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compute_gravity = body%mass * (dist ** 2)
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end function
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!-----------------------------------------------------------------------
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!-----------------------------------------------------------------------
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end module
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