`delta_out` and `delta_in` should not increase

Bug fix in procedure overlap: `delta_out` and `delta_in` should not increase.

Documentation_texfol/Graphiques/.gitignore

@@ -8,3 +8,4 @@ window.pdf
 periodicity.pdf
 copy.pdf
 set_all_outerm.pdf
+overlap.pdf

Documentation_texfol/Graphiques/GNUmakefile

-sources = window processes m3 call_graph input_output degeneracy periodicity copy set_all_outerm
+sources = window processes m3 call_graph input_output degeneracy periodicity copy set_all_outerm overlap
 
 objects := $(addsuffix .pdf, ${sources})
 

candidate_overlap.f90

@@ -6,8 +6,9 @@ contains
 
   function candidate_overlap(extr_map, list_vis, cyclone, delta_out, delta)
 
-    ! Find the eddies in extr_map that are valid and have a given
-    ! cyclonicity.
+    ! Find the eddies in extr_map that are valid, have a given
+    ! cyclonicity. Also, if delta_out < delta then the eddies should
+    ! not have a predecessor at time distance < delta.
 
     use derived_types, only: eddy
 
@@ -18,11 +19,17 @@ contains
     ! extremum. 0 at other points.
 
     type(eddy), intent(in):: list_vis(:)
-    ! Visible eddies at a given date. We need components valid and
-    ! cyclone to be defined.
+    ! Visible eddies at a given date. We need components valid,
+    ! cyclone and delta_in to be defined. Arriving in this subroutine,
+    ! list_vis%delta_in could be <= delta or huge(0).
 
     logical, intent(in):: cyclone ! cyclonicity of the target extremum
-    integer, intent(in):: delta_out, delta
+
+    integer, intent(in):: delta_out
+    ! Arriving in this subroutine, delta_out could be <= delta or
+    ! huge(0).
+
+    integer, intent(in):: delta
 
     !---------------------------------------------------------------------
 

derived_types.f90

@@ -27,12 +27,12 @@ module derived_types
      logical interpolated
      
      integer:: delta_in = huge(0)
-     ! Maximum difference in time subscript where there is a direct
-     ! predecessor. huge means there is no direct predecessor.
+     ! Minimum difference in time subscript where there is a direct
+     ! predecessor. Huge means there is no direct predecessor.
      
      integer:: delta_out = huge(0)
-     ! Maximum difference in time subscript where there is a direct
-     ! successor. huge means there is no direct succcessor.
+     ! Minimum difference in time subscript where there is a direct
+     ! successor. Huge means there is no direct succcessor.
 
      integer radius4
      ! ind_extr + radius4 - 1 in all four directions is inside outermost

overlap.f90

@@ -52,7 +52,9 @@ contains
 
     ! Local:
 
-    integer i1, i2, l, n_select, m
+    integer i1 ! eddy index of predecessor
+    integer i2 ! eddy index of successor
+    integer l, n_select, m
     type(polyline) polyline_1, polyline_2
     type(polygon) res_pol
 
@@ -80,10 +82,12 @@ contains
              urc(1) = min(urc(1), nlon)
           end if
 
+          ! Pre-select potential successors:
           selection = candidate_overlap(flow(j)%extr_map(llc(1):urc(1), &
                llc(2):urc(2)), flow(j)%list_vis, &
                flow(j - delta)%list_vis(i1)%cyclone, &
                flow(j - delta)%list_vis(i1)%delta_out, delta)
+          
           n_select = size(selection)
           if (n_select /= 0) polyline_1 &
                = merge(flow(j - delta)%list_vis(i1)%speed_cont%polyline, &
@@ -92,6 +96,8 @@ contains
 
           DO l = 1, n_select
              i2 = selection(l)
+             ! assertion {flow(j - delta)%list_vis(i1)%delta_out >=
+             ! delta .or. flow(j)%list_vis(i2)%delta_in >= delta}
              polyline_2 = merge(flow(j)%list_vis(i2)%speed_cont%polyline, &
                   flow(j)%list_vis(i2)%out_cont%polyline, &
                   flow(j)%list_vis(i2)%speed_cont%n_points /= 0)
@@ -127,8 +133,10 @@ contains
                         flow(j)%list_vis(i2)%ssh_extr, &
                         weight(flow(j - delta)%list_vis(i1), &
                         flow(j)%list_vis(i2)))
-                   flow(j - delta)%list_vis(i1)%delta_out = delta
-                   flow(j)%list_vis(i2)%delta_in = delta
+                   flow(j - delta)%list_vis(i1)%delta_out &
+                        = min(flow(j - delta)%list_vis(i1)%delta_out, delta)
+                   flow(j)%list_vis(i2)%delta_in &
+                        = min(flow(j)%list_vis(i2)%delta_in, delta)
                 end if
              end if
           end DO