[WP] (issue7 refract): fix variable in subroutine mpcfactors

- discard obsolete variables
- rename maxamp to refamp
- add version comment

src/ts/refract/sub/refract_mpc.f

@@ -31,6 +31,8 @@ c                      offset for scaling mode 3 as the actual offset
 c                      dependency is unknown
 c    20/11/12   V1.2   use field offset for scaling purposes, not plot
 c                      offset
+c    07/12/15   V1.3   mode 2 and 3 now refer scaling to average scaled
+c                      amplitude in defined offset range
 c
 c==============================================================================
 cS
@@ -45,8 +47,8 @@ c
       include 'refract_para.inc'
 c
 cE
-      integer i,j,tref
-      real trefoff, refmpc, maxamp, thisamp
+      integer i,j
+      real refmpc, refamp
       real refract_avgamp
 c
 c scaling mode 1: individual scaling
@@ -54,13 +56,13 @@ c ----------------------------------
       if (plpar_mode.eq.1) then
         do j=1,ntraces
           if (plpar_remav) then
-            maxamp=max(abs(maxval(j)-average(j)),abs(minval(j)-average(j)))
+            refamp=max(abs(maxval(j)-average(j)),abs(minval(j)-average(j)))
           else
-            maxamp=max(abs(maxval(j)),abs(minval(j)))
+            refamp=max(abs(maxval(j)),abs(minval(j)))
           endif
-          trv_mpc(j)=plpar_amp/maxamp
+          trv_mpc(j)=plpar_amp/refamp
           if (debug) print *,'DEBUG (mpcfactors): trace, mpc ',j,trv_mpc(j)
-          if (debug) print *,'DEBUG (mpcfactors): maxamp ',maxamp
+          if (debug) print *,'DEBUG (mpcfactors): refamp ',refamp
           if (debug) print *,'DEBUG (mpcfactors): maxval ',maxval(j)
           if (debug) print *,'DEBUG (mpcfactors): minval ',minval(j)
         enddo
@@ -69,8 +71,8 @@ c scaling mode 2: least offset trace is reference
 c -----------------------------------------------
       elseif (plpar_mode.eq.2) then
         j=1
-        maxamp=refract_avgamp(j, .true.)
-        refmpc=plpar_amp/(fieldoffset(tref)**plpar_expo)/maxamp
+        refamp=refract_avgamp(j, .true.)
+        refmpc=plpar_amp/refamp
 c set mpc factors
         do j=1,ntraces
           trv_mpc(j)=refmpc*(fieldoffset(j)**plpar_expo)
@@ -82,8 +84,8 @@ c -------------------------------------------------------------------
       elseif (plpar_mode.eq.3) then
 c go for files
         do i=1,nfiles
-          maxamp=refract_avgamp(i, .false.)
-          refmpc=plpar_amp/maxamp
+          refamp=refract_avgamp(i, .false.)
+          refmpc=plpar_amp/refamp
 c set mpc factors within file
           do j=1,ntraces
             if (fileindex(j).eq.i) then