libpsdxx [WP][DOC]: correct data type in function documentation

src/libs/libpsdxx/psd.h

@@ -238,12 +238,12 @@ namespace psd {
                           const unsigned int& nsamples,
                           const unsigned int& n_per_decade);
 
-   /*! sample values on a logarithmic frequency axis
+   /*! sample complex values on a logarithmic frequency axis
     */
    TDCISeries::Tseries log_sampling(const TDCISeries::Tcoc& s,
                                     const TDseries::Tcoc& f);
 
-   /*! sample complex values on a logarithmic frequency axis
+   /*! sample real values on a logarithmic frequency axis
     */
    TDISeries::Tseries log_sampling(const TDISeries::Tcoc& s,
                                    const TDseries::Tcoc& f);