libpsdxx [WP][FIX]: make LogTaper produce correct values

src/libs/libpsdxx/log_taper.cc

@@ -35,6 +35,7 @@
 
 #include <psdxx/helper.h>
 #include <psdxx/error.h>
+#include <psdxx/debug.h>
 #include <cmath>
 
 namespace psd {
@@ -46,21 +47,22 @@ namespace psd {
     {
       PSDXX_assert(f.size()>2,
                    "at least three values of frequency are required");
-      if (i==0)
+      PSDXX_assert((i>=f.f()) && (i<=f.l()),
+                   "index is out of range");
+      if (i==f.f())
       {
         this->Mloc=Flower_end;
-        this->Mli=new psd::helper::LogIndex(f(f.f()), f(f.f()+1), f(f.f()+2));
+        this->Mli=new psd::helper::LogIndex(f(i), f(i+1), f(i+2));
       }
-      else if (i==(f.size()-1))
+      else if (i==f.l())
       {
         this->Mloc=Fupper_end;
-        this->Mli=new psd::helper::LogIndex(f(f.l()-2), f(f.l()-1), f(f.l()));
+        this->Mli=new psd::helper::LogIndex(f(i-2), f(i-1), f(i));
       }
       else
       {
         this->Mloc=Fmiddle;
-        this->Mli=new psd::helper::LogIndex(f(f.f()+i-1), 
-                                            f(f.f()+i), f(f.f()+i+1));
+        this->Mli=new psd::helper::LogIndex(f(i-1), f(i), f(i+1));
       }
     } // LogTaper::LogTaper(const psd::TDseries::Tcoc& f,
       //                    const unsigned int& i)
@@ -89,7 +91,7 @@ namespace psd {
         // taper is 1 for frequency index <= 0
         if ((rindex > 0.) && (rindex < 1.))
         {
-          retval=0.5*(1.-std::sin(rindex*M_PI));
+          retval=0.5*(1.+std::cos(rindex*M_PI));
         }
         else if (rindex <= 0.)
         {
@@ -101,9 +103,14 @@ namespace psd {
         // index of center frequency is 2
         // index range is from +1 to +3
         // taper is 1 for frequency index >= 2
-        if ((rindex < 2.) && (rindex > 1.))
+        if ((rindex >= 1.) && (rindex < 2.))
         {
-          retval=0.5*(1.-std::sin(rindex*M_PI));
+          retval=0.5*(1.+std::cos(rindex*M_PI));
+          /*
+          std::cerr << PSDXX_value(f) << " "
+            << PSDXX_value(rindex) << " "
+            << PSDXX_value(retval) << std::endl;
+            */
         }
         else if (rindex >= 2.)
         {
@@ -114,7 +121,7 @@ namespace psd {
       {
         // index of center frequency is 1
         // index range is from 0 to +2
-        if ((rindex > -2.) && (rindex < 2.))
+        if ((rindex > -0.) && (rindex < 2.))
         {
           retval=0.5*(1.-std::cos(rindex*M_PI));
         }

src/libs/libpsdxx/testlogtaper.gpt

@@ -20,7 +20,10 @@ set output 'logtaper.ps'
 set logscale x
 unset logscale y
 set mxtics 10
-set grid
+set mytics 5
+set grid xtics,ytics 
+set grid mxtics,mytics 
+set key left
 set title 'LogTaper'
 set xlabel 'frequency / Hz'
 set ylabel 'taper value'

src/libs/libpsdxx/testpsdxx.cc

@@ -153,9 +153,9 @@ int main(int iargc, char* argv[])
 
   if (opt.logtaper)
   {
-    const int nsamples=300;
+    const int nsamples=100;
     cout << "test class LogTaper" << endl;
-    CODE( psd::TDseries linf=psd::lin_frequency(0.1,nsamples) );
+    CODE( psd::TDseries linf=psd::lin_frequency(0.01,nsamples*10) );
     CODE( psd::TDseries logf=psd::log_frequency(0.1,nsamples,6) );
     CODE( psd::helper::LogTaper logt(logf, opt.taperindex) ); 
     DUMP( logf );