[FEATURE] (libtfsxx): implement new filter GaussianNoise

The filter GaussianNoise is provided in tidofi through keyword noi.
It adds white Gaussian Noise of a given rms amplitude (specified through
filter parameter) to each time series.

The filter is implemented in libtsxx. tidofi is additionally linked against
libgsl to provide random number generator.

src/libs/libtsxx/filter.cc

@@ -4,11 +4,11 @@
  * ----------------------------------------------------------------------------
  * 
  * \author Thomas Forbriger
- * \date 31/07/2015
+ * \date 19/03/2016
  * 
  * some time series filter classes (implementation)
  * 
- * Copyright (c) 2005, 2015 by Thomas Forbriger (BFO Schiltach) 
+ * Copyright (c) 2005, 2015, 2016 by Thomas Forbriger (BFO Schiltach) 
  *
  * ----
  * This program is free software; you can redistribute it and/or modify
@@ -51,15 +51,18 @@
  *                        - take usage text from text file
  *  - 31/07/2015   V1.10 
  *                        - add filter Powerof
+ *  - 19/03/2016   V1.11 
+ *                        - add filter GaussianNoise
  * 
  * ============================================================================
  */
 #define TF_FILTER_CC_VERSION \
-  "TF_FILTER_CC   V1.10"
+  "TF_FILTER_CC   V1.11"
 
 #include <cmath>
 #include <sstream>
 #include <algorithm>
+#include <tsxx/random.h>
 #include <tsxx/filter.h>
 #include <tsxx/filter_usage_text.h>
 #include <aff/functions/avg.h>
@@ -195,6 +198,18 @@ namespace ts {
 
     /*----------------------------------------------------------------------*/
 
+    //! add Gaussian noise
+    Ttimeseries GaussianNoise::operator()(const Ttimeseries& s,
+                                          const bool& debug) const
+      {  
+        Tseries x=s;
+        Tseries n=ts::rnd::dugauss(x.size())*Ma;
+        x += n;
+        return s; 
+      }
+
+    /*----------------------------------------------------------------------*/
+
     //! rectification
     Ttimeseries Rectifier::operator()(const Ttimeseries& s,
                                       const bool& debug) const
@@ -434,6 +449,9 @@ namespace ts {
       } else if (ID=="del") {
         is >> v;
         fh=Tfh(new Delay(v));
+      } else if (ID=="noi") {
+        is >> v;
+        fh=Tfh(new GaussianNoise(v));
       } else if (ID=="nrm") {
         is >> v;
         fh=Tfh(new Normalize(v));

src/libs/libtsxx/filter.h

@@ -4,11 +4,11 @@
  * ----------------------------------------------------------------------------
  * 
  * \author Thomas Forbriger
- * \date 31/07/2015
+ * \date 19/03/2016
  * 
  * some time series filter classes (prototypes)
  * 
- * Copyright (c) 2005, 2015 by Thomas Forbriger (BFO Schiltach) 
+ * Copyright (c) 2005, 2015, 2016 by Thomas Forbriger (BFO Schiltach) 
  *
  * ----
  * This program is free software; you can redistribute it and/or modify
@@ -43,6 +43,8 @@
  *                        - added cumsum
  *  - 31/07/2015   V1.7  
  *                        - add filter Powerof
+ *  - 19/03/2016   V1.8  
+ *                        - add filter GaussianNoise
  * 
  * ============================================================================
  */
@@ -51,7 +53,7 @@
 #ifndef TF_FILTER_H_VERSION
 
 #define TF_FILTER_H_VERSION \
-  "TF_FILTER_H   V1.7"
+  "TF_FILTER_H   V1.8"
 
 #include<tsxx/filterbase.h>
 
@@ -306,6 +308,22 @@ namespace ts {
 
     /*----------------------------------------------------------------------*/
 
+    /*! \brief Add random Gaussian noise.
+     * \ingroup filter
+     *
+     * \param a rms amplitude of noise to be added
+     */
+    class GaussianNoise: public ts::filter::BasicFilter {
+      public:
+        GaussianNoise(const double& a): Ma(a) { }
+        Ttimeseries operator()(const Ttimeseries& s,
+                               const bool& debug=false) const;
+      private:
+        double Ma;
+    }; // class GaussianNoise
+
+    /*----------------------------------------------------------------------*/
+
     /*! create a filter
      * \ingroup filter
      */

src/libs/libtsxx/filter_usage_text.txt

@@ -6,7 +6,7 @@
 # description of filters provided in namespace ts::filter
 # as provided through filter.h and defined in filter.cc
 #
-available filters (version 2015/07/31):
+available filters (version 2016/03/19):
 tre n      remove trend found in first n samples
            (n=0: use all samples)
 avg n      remove average found in first n samples
@@ -31,5 +31,6 @@ rec        rectify signal
 cus        calculate cumulative sum
 iset n1,n2,v
            set samples n1-n2 to value v
+noi a      add Gaussian random noise of rms amplitude a
 # 
 # ----- END OF filter_usage_text.txt ----- 

src/ts/wf/Makefile

 # this is <Makefile>
 # ----------------------------------------------------------------------------
-# $Id$
 # 
 # Copyright (c) 2005 by Thomas Forbriger (BFO Schiltach) 
 # 
@@ -48,6 +47,7 @@
 #    02/01/2014   V1.11  removed signal generators, added tisli suspect
 #    01/02/2014 thof:    rewrite all linker rules with libraries in
 #                        proper order
+#    19/03/2016 thof:    tidofi requires libgsl for filter GaussianNoise
 # 
 # ============================================================================
 
@@ -202,7 +202,7 @@ sigval sigscale geophone gatherdiff cross autocorr: \
 tidofi: \
   %: %.o
 	$(LINK.cpp) $^ $(LOADLIBES) $(LDLIBS) -o $@ \
-	  -ltsxx -lcseife $(LIBDATRWXX) -ltfxx
+	  -ltsxx -lcseife $(LIBDATRWXX) -ltfxx -lgsl -lgslcblas
 
 fidasexx: \
   %: %.o