Allow field radius4 to be missing

Useful to read shapefiles from conversion of Matlab data.

Common/read_eddy.f90

@@ -63,8 +63,13 @@ contains
     
     call dbf_read_attribute_03(e%out_cont%ssh, hshp%outermost, hshp%out_ssh, &
          ishape)
-    call dbf_read_attribute_03(e%radius4, hshp%outermost, hshp%out_radius4, &
-         ishape)
+
+    if (hshp%out_radius4 /= - 1) then
+       call dbf_read_attribute_03(e%radius4, hshp%outermost, hshp%out_radius4, &
+            ishape)
+    else
+       e%radius4 = - 1
+    end if
 
     call shp_read_object_03(hshp%outermost, ishape, psobject)
     p = shpobj2pol(psobject)

Common/read_field_indices.F90

@@ -7,6 +7,7 @@ contains
   subroutine read_field_indices(hshp)
 
     ! Libraries:
+    use shapelib, only: dbfgetfieldindex
     use shapelib_03, only: dbf_get_field_index_03
 
     use derived_types, only: shpc
@@ -28,7 +29,9 @@ contains
     call dbf_get_field_index_03(hshp%outermost, "date", hshp%out_date)
     call dbf_get_field_index_03(hshp%outermost, "eddy_index", &
          hshp%out_eddy_index)
-    call dbf_get_field_index_03(hshp%outermost, "radius4", hshp%out_radius4)
+
+    ! We allow the field radius4 to be missing:
+    hshp%out_radius4 = dbfgetfieldindex(hshp%outermost, "radius4")
 
     call dbf_get_field_index_03(hshp%max_speed, "r_eq_area", &
          hshp%max_speed_r_eq_area)