grepg [WP]: provide usage information for new options

src/green/grepg/grepg.f

@@ -247,6 +247,8 @@ c  give basic information
       print *,'               ',
      &'       [-E] [-p p] [-L] [-e limit] [-m limit]'
       print *,'               ',
+     &'       [-Xb l,u] [-Yb l,u]'
+      print *,'               ',
      &'       [-s] [-f n] [-st] [-N c,w] [-n value] [-M limit]'
       print *,'               ',
      &'       [-S] [-t n,m] [-Q] [-K o,t]'
@@ -346,6 +348,23 @@ c  give basic information
      &   ' that ist used to evaluate the normalizing'
         print *,'              factor for the whole dataset'
         print *,'              (default is ',optarg(16)(1:3),').'
+        print *,' '
+        print *,' set scale ranges'
+        print *,' '
+        print *,'  -Xb l,u    ',
+     &   ' set lower and upper boundary value for abscissa'
+        print *,'             ',
+     &   ' l: lower boundary value; smallest value on axis'
+        print *,'             ',
+     &   '    will not be smaller than ''l'' '
+        print *,'             ',
+     &   ' u: upper boundary value; largest value on axis'
+        print *,'             ',
+     &   '    will not be larger than ''u'' '
+        print *,'  -Yb l,u    ',
+     &   ' set lower and upper boundary value for ordinate'
+        print *,'             ',
+     &   ' see -Xb for a definition of parameters l and u'
         print *,' '
         print *,'  normalize data'
         print *,' '