sigfit [WP]: add debug option

problem: sigfit produces unreasonable data start time values upon output of
residuals file

src/ts/wf/sigfit.cc

@@ -43,11 +43,12 @@
  *  - 20/02/2012   V1.7   read and write any file format (damb)
  *                        trace selecttion requires skip trace (thof)
  *  - 22/11/2016   V1.8   make use of new output facilities in libtsxx
+ *  - 13/04/2018   V1.9 
  * 
  * ============================================================================
  */
 #define SIGFIT_VERSION \
-  "SIGFIT   V1.8   fit signal by trial-signals"
+  "SIGFIT   V1.9   fit signal by trial-signals"
 
 #include <fstream>
 #include <iostream>
@@ -82,7 +83,7 @@ using std::endl;
 
 // structure to store commandline options
 struct Options {
-  bool verbose;
+  bool verbose, debug;
   double Tdate;
   bool truncate;
   std::string residualname;
@@ -143,7 +144,7 @@ int main(int iargc, char* argv[])
   char usage_text[]=
   {
     SIGFIT_VERSION "\n"
-    "usage: sigfit [-v] [-Tdate v] [-truncate]" "\n"
+    "usage: sigfit [-v] [-DEBUG] [-Tdate v] [-truncate]" "\n"
     "              [-Sramp[=v]] [-Sconst[=v]] [-Sexp[=v]]" "\n"
     "              [-residual f]" "\n"
     "              [-searchrange[=r]] [-equalsearch] [-skip n]" "\n"
@@ -242,6 +243,8 @@ int main(int iargc, char* argv[])
     {"itype",arg_yes,"sff"},
     // 12: output file format
     {"otype",arg_yes,"sff"},
+    // 13: produce debug output
+    {"DEBUG",arg_no,"-"},
     {NULL}
   };
 
@@ -296,6 +299,7 @@ int main(int iargc, char* argv[])
   opt.tcexp=cmdline.double_arg(10);
   opt.itype=cmdline.string_arg(11);
   opt.otype=cmdline.string_arg(12);
+  opt.debug=cmdline.optset(13);
 
   /*----------------------------------------------------------------------*/