libpsdxx [WP]: adjust test program to report center frequency

src/libs/libpsdxx/testlogtaper.gpt

@@ -27,5 +27,5 @@ set key left
 set title 'LogTaper'
 set xlabel 'frequency / Hz'
 set ylabel 'taper value'
-plot 'logtaper.xxx' skip 12 u 2:3 w l
+plot 'logtaper.xxx' skip 11 u 2:3 w l
 #    EOF

src/libs/libpsdxx/testpsdxx.cc

@@ -159,12 +159,12 @@ int main(int iargc, char* argv[])
     CODE( psd::TDseries logf=psd::log_frequency(0.1,nsamples,6) );
     CODE( psd::helper::LogTaper logt(logf, opt.taperindex) ); 
     DUMP( logf );
-    cout << PSDXX_value( logf(opt.taperindex) ) << endl;
+    cerr << PSDXX_value( logf(opt.taperindex) ) << endl;
     for (int i=linf.f(); i<= linf.l(); ++i)
     {
       cout << i << " " << linf(i) << " " << logt(linf(i)) << endl;
     }
-    cout << PSDXX_value( logt.sum() ) << endl;
+    cerr << PSDXX_value( logt.sum() ) << endl;
   } // if (opt.logtaper)
 }