[12] | 1 | MODULE spherical_geom_mod |
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| 2 | USE genmod |
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| 3 | |
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| 4 | |
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| 5 | |
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| 6 | CONTAINS |
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| 7 | |
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| 8 | |
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| 9 | |
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| 10 | |
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| 11 | SUBROUTINE lonlat2xyz(lon,lat,xyz) |
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| 12 | IMPLICIT NONE |
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| 13 | REAL(rstd),INTENT(IN) :: lon |
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| 14 | REAL(rstd),INTENT(IN) :: lat |
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| 15 | REAL(rstd),INTENT(OUT) :: xyz(3) |
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| 16 | |
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| 17 | xyz(1)=cos(lon)*cos(lat) |
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| 18 | xyz(2)=sin(lon)*cos(lat) |
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| 19 | xyz(3)=sin(lat) |
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| 20 | |
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| 21 | END SUBROUTINE lonlat2xyz |
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| 22 | |
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| 23 | |
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| 24 | SUBROUTINE xyz2lonlat(xyz,lon,lat) |
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| 25 | IMPLICIT NONE |
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| 26 | REAL(rstd),INTENT(IN) :: xyz(3) |
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| 27 | REAL(rstd),INTENT(OUT) :: lon |
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| 28 | REAL(rstd),INTENT(OUT) :: lat |
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| 29 | |
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| 30 | REAL(rstd) :: coslat |
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| 31 | REAL(rstd) :: xyzn(3) |
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| 32 | |
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| 33 | xyzn(:)=xyz(:)/sqrt(sum(xyz(:)**2)) |
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| 34 | |
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| 35 | lat=asin(xyzn(3)) |
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| 36 | coslat=cos(lat) |
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| 37 | IF (abs(coslat)<1e-15) THEN |
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| 38 | lon=0. |
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| 39 | ELSE |
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| 40 | lon=acos(MAX(MIN((xyzn(1)/coslat),1.),-1.)) |
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| 41 | IF (xyzn(2)/coslat<0) lon=-lon |
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| 42 | ENDIF |
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| 43 | |
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| 44 | END SUBROUTINE xyz2lonlat |
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| 45 | |
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| 46 | |
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| 47 | SUBROUTINE dist_cart(A,B,d) |
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| 48 | USE vector |
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| 49 | IMPLICIT NONE |
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| 50 | REAL(rstd),INTENT(IN) :: A(3) |
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| 51 | REAL(rstd),INTENT(IN) :: B(3) |
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| 52 | REAL(rstd),INTENT(OUT) :: d |
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| 53 | |
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| 54 | REAL(rstd) :: n(3) |
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| 55 | CALL cross_product2(A,B,n) |
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| 56 | d=asin(sqrt(sum(n**2))) |
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| 57 | |
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| 58 | END SUBROUTINE dist_cart |
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| 59 | |
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| 60 | |
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| 61 | SUBROUTINE dist_lonlat(lonA,latA,lonB,latB,d) |
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| 62 | IMPLICIT NONE |
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| 63 | REAL(rstd),INTENT(IN) :: lonA |
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| 64 | REAL(rstd),INTENT(IN) :: latA |
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| 65 | REAL(rstd),INTENT(IN) :: lonB |
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| 66 | REAL(rstd),INTENT(IN) :: latB |
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| 67 | REAL(rstd),INTENT(OUT) :: d |
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| 68 | |
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| 69 | d=acos(MAX(MIN(sin(latA)*sin(latB)+cos(latA)*cos(latB)*cos(lonA-lonB),1.),-1.)) |
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| 70 | |
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| 71 | END SUBROUTINE dist_lonlat |
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| 72 | |
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| 73 | SUBROUTINE surf_triangle(A,B,C,surf) |
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| 74 | REAL(rstd),INTENT(IN) :: A(3) |
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| 75 | REAL(rstd),INTENT(IN) :: B(3) |
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| 76 | REAL(rstd),INTENT(IN) :: C(3) |
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| 77 | REAL(rstd),INTENT(OUT) :: Surf |
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| 78 | |
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| 79 | REAL(rstd) :: AB,AC,BC |
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[15] | 80 | REAL(rstd) :: s,x |
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[12] | 81 | |
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| 82 | CALL dist_cart(A,B,AB) |
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| 83 | CALL dist_cart(A,C,AC) |
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| 84 | CALL dist_cart(B,C,BC) |
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| 85 | |
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| 86 | s=(AB+AC+BC)/2 |
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[15] | 87 | x=tan(s/2) * tan((s-AB)/2) * tan((s-AC)/2) * tan((s-BC)/2) |
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| 88 | IF (x<0) x=0. |
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| 89 | surf=4*atan(sqrt( x)) |
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[12] | 90 | |
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| 91 | END SUBROUTINE surf_triangle |
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| 92 | |
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| 93 | |
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| 94 | SUBROUTINE div_arc(A,B,frac,C) |
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| 95 | IMPLICIT NONE |
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| 96 | REAL(rstd),INTENT(IN) :: A(3) |
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| 97 | REAL(rstd),INTENT(IN) :: B(3) |
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| 98 | REAL(rstd),INTENT(IN) :: frac |
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| 99 | REAL(rstd),INTENT(OUT) :: C(3) |
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| 100 | |
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| 101 | REAL(rstd) :: d |
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| 102 | REAL(rstd) :: M(3,3) |
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| 103 | REAL(rstd) :: alpha(3,3) |
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| 104 | INTEGER :: IPIV(3) |
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| 105 | INTEGER :: info |
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| 106 | REAL(rstd) :: xa,xb,xc |
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| 107 | REAL(rstd) :: ya,yb,yc |
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| 108 | REAL(rstd) :: za,zb,zc |
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| 109 | REAL(rstd) :: alpha_A,alpha_B,alpha_C |
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| 110 | REAL(rstd) :: x,y,z |
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| 111 | REAL(rstd) :: a1,a2,a3 |
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| 112 | REAL(rstd) :: b1,b2,b3 |
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| 113 | |
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| 114 | |
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| 115 | xa=A(1) ; ya=A(2) ; za=A(3) |
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| 116 | xb=B(1) ; yb=B(2) ; zb=B(3) |
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| 117 | |
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| 118 | CALL dist_cart(A,B,d) |
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| 119 | |
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| 120 | C(1)=cos(frac*d) |
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| 121 | C(2)=cos((1-frac)*d) |
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| 122 | C(3)=0. |
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| 123 | |
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| 124 | xc=ya*zb-yb*za ; yc=-(xa*zb-xb*za) ; zc=xa*yb-xb*ya |
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| 125 | |
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| 126 | M(1,1)=xa ; M(1,2)=ya ; M(1,3)=za |
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| 127 | M(2,1)=xb ; M(2,2)=yb ; M(2,3)=zb |
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| 128 | M(3,1)=xc ; M(3,2)=yc ; M(3,3)=zc |
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[13] | 129 | stop 'STOP' |
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| 130 | ! CALL DGESV(3,1,M,3,IPIV,C,3,info) |
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[12] | 131 | |
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| 132 | END SUBROUTINE div_arc |
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| 133 | |
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| 134 | SUBROUTINE div_arc_bis(A,B,frac,C) |
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| 135 | IMPLICIT NONE |
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| 136 | REAL(rstd),INTENT(IN) :: A(3) |
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| 137 | REAL(rstd),INTENT(IN) :: B(3) |
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| 138 | REAL(rstd),INTENT(IN) :: frac |
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| 139 | REAL(rstd),INTENT(OUT) :: C(3) |
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| 140 | |
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| 141 | C=A*(1-frac)+B*frac |
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| 142 | C=C/sqrt(sum(C**2)) |
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| 143 | END SUBROUTINE div_arc_bis |
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| 144 | |
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| 145 | |
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[15] | 146 | SUBROUTINE circumcenter(A0,B0,C0,Center) |
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[12] | 147 | USE vector |
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| 148 | IMPLICIT NONE |
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| 149 | REAL(rstd), INTENT(IN) :: A0(3),B0(3),C0(3) |
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| 150 | REAL(rstd), INTENT(OUT) :: Center(3) |
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| 151 | |
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| 152 | REAL(rstd) :: a(3),b(3),c(3) |
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| 153 | |
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| 154 | a=A0/sqrt(sum(A0**2)) |
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| 155 | b=B0/sqrt(sum(B0**2)) |
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| 156 | c=C0/sqrt(sum(C0**2)) |
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| 157 | |
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| 158 | CALL Cross_product2(b-a,c-b,center) |
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| 159 | center=center/sqrt(sum(center**2)) |
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| 160 | |
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[15] | 161 | END SUBROUTINE circumcenter |
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[12] | 162 | |
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| 163 | |
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[15] | 164 | SUBROUTINE compute_centroid(points,n,centr) |
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| 165 | USE vector |
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[12] | 166 | IMPLICIT NONE |
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[15] | 167 | INTEGER :: n |
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| 168 | REAL(rstd), INTENT(IN) :: points(3,n) |
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| 169 | REAL(rstd), INTENT(OUT) :: Centr(3) |
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[12] | 170 | |
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[15] | 171 | REAL(rstd) :: p1(3),p2(3),cross(3) |
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| 172 | REAL(rstd) :: norm_cross |
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| 173 | INTEGER :: i,j |
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| 174 | |
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| 175 | Centr(:)=0 |
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| 176 | DO i=1,n |
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| 177 | j=MOD(i,n)+1 |
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| 178 | p1=points(:,i)/norm(points(:,i)) |
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| 179 | p2=points(:,j)/norm(points(:,j)) |
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| 180 | CALL cross_product2(p1,p2,cross) |
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| 181 | norm_cross=norm(cross) |
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| 182 | if (norm_cross<1e-10) CYCLE |
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| 183 | |
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| 184 | Centr(:)=centr(:)+asin(norm_cross)*cross(:)/norm_cross |
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| 185 | ENDDO |
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| 186 | |
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| 187 | Centr(:)=centr(:)/norm(centr(:)) |
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[12] | 188 | |
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[15] | 189 | END SUBROUTINE compute_centroid |
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[12] | 190 | |
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| 191 | END MODULE spherical_geom_mod |
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| 192 | |
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| 193 | |
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