add temporary comments for understanding

volgrid6d/volgrid6d_alchimia_class.F03

@@ -64,9 +64,10 @@ subroutine make_vg6d(mayvfn,mybin,mybout,vg6din,vg6dout,allvarcomputed)
 ntime=size(vg6din%time)
 ntimerange=size(vg6din%timerange)
 
-!we have to make a new volume with var required in input function plus var for output
-
-!star with input variables
+! we have to make a new volume with var required in input function plus var for output
+! start with input variables
+! deletenote: mybin() corresponds to vg6din%var()
+! deletenote: after 2 following big loops it is not guaranteed that all elements of mybin are in newbout
 newbout=cmiss
 
 do i=1, size(mayvfn%fnds)
@@ -104,7 +105,6 @@ subroutine make_vg6d(mayvfn,mybin,mybout,vg6din,vg6dout,allvarcomputed)
 
 ! create output volume
 call init(vg6dout, vg6din%griddim, vg6din%time_definition, categoryappend="generated by alchimia make")
-!call volgrid6d_alloc(vg6dout, vg6din%griddim%dim, ntime, nlevel, ntimerange, nvar)
 call volgrid6d_alloc(vg6dout, ntime=ntime, nlevel=nlevel, ntimerange=ntimerange, nvar=nvar)
 call volgrid6d_alloc_vol(vg6dout,inivol=.true.,decode=.true.)
 
@@ -115,13 +115,17 @@ subroutine make_vg6d(mayvfn,mybin,mybout,vg6din,vg6dout,allvarcomputed)
 ! now I copy the needed input variables from input volume to output 
 DO ivar=1, nvar
   ivarin  = index_c(mybin,newbout(ivar))
-  ivarout = ivar
+  ivarout = ivar ! why do i need to use ivarout as alias for ivar?
 
-  if (ivarin == 0) then
-    call l4f_log(L4F_debug,"variable to compute in make_vg6d: "//newbout(ivar))
-    cycle
-  end if
+  IF (ivarin == 0) THEN
+#ifdef DEBUG
+    CALL l4f_log(L4F_debug,"variable to compute in make_vg6d: "//newbout(ivar))
+#endif
+    CYCLE
+  ENDIF
 
+! delete note: varvg6d (future vg6dout%var? is filled in sparse mode? probably not because newbout
+! contains at the beginning only elements that are also in mybin
   varvg6d(ivarout)=vg6din%var(ivarin)
   call init(gaid_template)
 
@@ -148,6 +152,7 @@ subroutine make_vg6d(mayvfn,mybin,mybout,vg6din,vg6dout,allvarcomputed)
   ENDDO
 ENDDO
 
+! delete note: am i sure that up to now i have filled varvg6d exactly up to nvarin?
 CALL vargrib2varbufr(varvg6d(:nvarin), varv7d(:nvarin), c_funcgb)
 
 do ivar = nvarin+1, nvar