--- trunk/libf/dyn3d/coefpoly.f	2008/02/27 13:16:39	3
+++ trunk/dyn3d/coefpoly.f	2015/01/28 16:10:02	121
@@ -1,40 +1,47 @@
-!
-! $Header: /home/cvsroot/LMDZ4/libf/dyn3d/coefpoly.F,v 1.1.1.1 2004/05/19 12:53:05 lmdzadmin Exp $
-!
-      SUBROUTINE coefpoly ( Xf1, Xf2, Xprim1, Xprim2, xtild1,xtild2 ,
-     ,                                          a0,a1,a2,a3         )
-      IMPLICIT NONE
-c
-c   ...  Auteur :   P. Le Van  ...
-c
-c
-c    Calcul des coefficients a0, a1, a2, a3 du polynome de degre 3 qui
-c      satisfait aux 4 equations  suivantes :
-
-c    a0 + a1*xtild1 + a2*xtild1*xtild1 + a3*xtild1*xtild1*xtild1 = Xf1
-c    a0 + a1*xtild2 + a2*xtild2*xtild2 + a3*xtild2*xtild2*xtild2 = Xf2
-c               a1  +     2.*a2*xtild1 +     3.*a3*xtild1*xtild1 = Xprim1
-c               a1  +     2.*a2*xtild2 +     3.*a3*xtild2*xtild2 = Xprim2
-
-c  On en revient a resoudre un systeme de 4 equat.a 4 inconnues a0,a1,a2,a3
-
-      REAL*8 Xf1, Xf2,Xprim1,Xprim2, xtild1,xtild2, xi 
-      REAL*8 Xfout, Xprim
-      REAL*8 a1,a2,a3,a0, xtil1car, xtil2car,derr,x1x2car
-
-      xtil1car = xtild1 * xtild1
-      xtil2car = xtild2 * xtild2 
-
-      derr= 2. *(Xf2-Xf1)/( xtild1-xtild2)
-
-      x1x2car = ( xtild1-xtild2)*(xtild1-xtild2)
-
-      a3 = (derr + Xprim1+Xprim2 )/x1x2car
-      a2     = ( Xprim1 - Xprim2 + 3.* a3 * ( xtil2car-xtil1car ) )    /
-     /           (  2.* ( xtild1 - xtild2 )  )
+module coefpoly_m
 
-      a1     = Xprim1 -3.* a3 * xtil1car     -2.* a2 * xtild1
-      a0     =  Xf1 - a3 * xtild1* xtil1car -a2 * xtil1car - a1 *xtild1
+  IMPLICIT NONE
 
-      RETURN
-      END
+contains
+
+  SUBROUTINE coefpoly(xf1, xf2, xprim1, xprim2, xtild1, xtild2, a0, a1, a2, a3)
+
+    ! From LMDZ4/libf/dyn3d/coefpoly.F, version 1.1.1.1 2004/05/19 12:53:05
+
+    ! Author: P. Le Van
+
+    ! Calcul des coefficients a0, a1, a2, a3 du polynôme de degré 3 qui
+    ! satisfait aux 4 équations suivantes :
+
+    ! a0 + a1 * xtild1 + a2 * xtild1**2 + a3 * xtild1**3 = Xf1
+    ! a0 + a1 * xtild2 + a2 * xtild2**2 + a3 * xtild2**3 = Xf2
+    ! a1 + 2. * a2 * xtild1 + 3. * a3 * xtild1**2 = Xprim1
+    ! a1 + 2. * a2 * xtild2 + 3. * a3 * xtild2**2 = Xprim2
+
+    ! On en revient à resoudre un système de 4 équations à 4 inconnues
+    ! a0, a1, a2, a3.
+
+    DOUBLE PRECISION, intent(in):: xf1, xf2, xprim1, xprim2, xtild1, xtild2
+    DOUBLE PRECISION, intent(out):: a0, a1, a2, a3
+
+    ! Local:
+    DOUBLE PRECISION xtil1car, xtil2car, derr, x1x2car
+
+    !------------------------------------------------------------
+
+    xtil1car = xtild1 * xtild1
+    xtil2car = xtild2 * xtild2
+
+    derr = 2. * (xf2-xf1)/(xtild1-xtild2)
+
+    x1x2car = (xtild1-xtild2) * (xtild1-xtild2)
+
+    a3 = (derr+xprim1+xprim2)/x1x2car
+    a2 = (xprim1-xprim2+3. * a3 * (xtil2car-xtil1car))/(2. * (xtild1-xtild2))
+
+    a1 = xprim1 - 3. * a3 * xtil1car - 2. * a2 * xtild1
+    a0 = xf1 - a3 * xtild1 * xtil1car - a2 * xtil1car - a1 * xtild1
+
+  END SUBROUTINE coefpoly
+
+end module coefpoly_m