mspass::seismic::BasicSpectrum Class Reference

#include <BasicSpectrum.h>

Inheritance diagram for mspass::seismic::BasicSpectrum:

Public Member Functions
	BasicSpectrum ()
	BasicSpectrum (const double dfin, const double f0in, const double dtin, const int npts_in)
	BasicSpectrum (const BasicSpectrum &parent)
BasicSpectrum &	operator= (const BasicSpectrum &parent)
bool	live () const
bool	dead () const
void	kill ()
void	set_live ()
double	df () const
double	f0 () const
double	dt () const
	Return the original sample interval of data used to generate spectrum. More...
double	rayleigh () const
	Return the Rayleigh bin size for this spectrum. More...
int	timeseries_npts () const
int	sample_number (const double f) const
void	set_df (const double dfin)
void	set_f0 (const double f0in)
void	set_dt (const double dtin)
void	set_npts (const int npts_in)
virtual std::vector< double >	frequencies () const =0
virtual double	frequency (const int sample_number) const =0
virtual size_t	nf () const =0
virtual double	Nyquist () const =0

Protected Attributes
double	dfval
double	f0val
double	parent_dt
double	parent_npts
bool	is_live

Detailed Description

Base class for family of data objects created by Fourier transforms.

There are a range of algorithms used in seismology that center on the use of Fourier Transforms. This base class is intended to be used as the base for any mspass C++ data object based on Fourier transforms where the data are stored with a vector defined on a uniform grid in frequency. That means any algorithm based on fFTs. The value of using a base class is that power spectra and complex spectra have many common concpets shared by this base class. Classic use of inheritance to avoid redundant code.

Constructor & Destructor Documentation

BasicSpectrum() [1/3]

mspass::seismic::BasicSpectrum::BasicSpectrum ( )

inline

Default constructor. sets frequency interval to 1 and f0 to 0

{dfval=1.0;f0val=0.0;};

BasicSpectrum() [2/3]

mspass::seismic::BasicSpectrum::BasicSpectrum ( const double  dfin, const double  f0in, const double  dtin, const int  npts_in  )

inline

Parameterized constructor.

Parameters

dfin	frequency bin size
f0in	frequency of first component of data vector of regular frequency grid.
dtin	parent sample interval of spectrum estimate.
npts_in	number of actual samples of parent time series (may not be the same as spectrum link when zero padding is used. subclasses should provide a way to handle zero padding

  {
    is_live=false;
    dfval=dfin;
    f0val=f0in;
    parent_dt=dtin;
    parent_npts=npts_in;
  };

BasicSpectrum() [3/3]

mspass::seismic::BasicSpectrum::BasicSpectrum ( const BasicSpectrum &  parent )

inline

Standard copy constructor

  {
    is_live=parent.is_live;
    dfval=parent.dfval;
    f0val=parent.f0val;
    parent_dt=parent.parent_dt;
    parent_npts=parent.parent_npts;
  };

Member Function Documentation

dead()

bool mspass::seismic::BasicSpectrum::dead ( ) const

inline

Test live condition of the data.

Returns true if the data are marked as being bad This method is part of a four methods for handling the concept of "live"==gppd versus "dead" == bad. The concept was borrowed from seismic reflection processing. This method is the negation of the live method.

{return !is_live;};

df()

double mspass::seismic::BasicSpectrum::df ( ) const

inline

Return the (fixed) frequemcy bin size.

{return this->dfval;};

dt()

double mspass::seismic::BasicSpectrum::dt ( ) const

inline

Return the original sample interval of data used to generate spectrum.

When zero padding is used the original sample interval of data cannot be known without additional data. In this implementation we require the user to store that information with a protected attribute within the object. This retrieves that stored value.

{return this->parent_dt;};

f0()

double mspass::seismic::BasicSpectrum::f0 ( ) const

inline

Return the frequency of the first (0) component of the spectrum vector. This value is normally 0 but the api allows it to be nonzero. That is useful for windowing to store only data in a limited passband.

{return this->f0val;};

frequencies()

virtual std::vector<double> mspass::seismic::BasicSpectrum::frequencies ( ) const

pure virtual

Return an std::vector container containing the frequency of each sample in the spectrum vector. Commonly necessary for plotting. Made virtual because nf method needs to be virtual.

Implemented in mspass::seismic::PowerSpectrum.

frequency()

virtual double mspass::seismic::BasicSpectrum::frequency ( const int  sample_number ) const

pure virtual

Return frequency at a specified sample number. Virtual to allow subclasses to throw an error for illegal value.

Implemented in mspass::seismic::PowerSpectrum.

kill()

void mspass::seismic::BasicSpectrum::kill ( )

inline

Mark this datum bad.

Returns true if the data are marked as being good. This method is part of a four methods for handling the concept of "live"==gppd versus "dead" == bad. The concept was borrowed from seismic reflection processing.

{is_live=false;};

live()

bool mspass::seismic::BasicSpectrum::live ( ) const

inline

Test live condition of the data.

Returns true if the data are marked as being good. This method is part of a four methods for handling the concept of "live"==gppd versus "dead" == bad. The concept was borrowed from seismic reflection processing.

{return is_live;};

nf()

virtual size_t mspass::seismic::BasicSpectrum::nf ( ) const

pure virtual

Return the number of frequency bin.

Implemented in mspass::seismic::PowerSpectrum.

Nyquist()

virtual double mspass::seismic::BasicSpectrum::Nyquist ( ) const

pure virtual

Return the Nyquist frequency. Virtual because if f0 is not zero and the number of points is not the full fft output this needs to be handled differently.

Implemented in mspass::seismic::PowerSpectrum.

rayleigh()

double mspass::seismic::BasicSpectrum::rayleigh ( ) const

inline

Return the Rayleigh bin size for this spectrum.

The Rayleigh bin size of a spectrum is 1/T where T is the length of the original time series. This method returns that attribute of this spectrum. Note the rayleigh and df methods will return the same number only when a spectrum is computed with no zero padding.

                         {
    return 1.0/(this->parent_dt*static_cast<double>(this->parent_npts));
  };

sample_number()

int mspass::seismic::BasicSpectrum::sample_number ( const double  f ) const

inline

Return the integer sample number of the closest sample to the specified frequency. Uses rounding. Will throw a MsPASSError object if the specified frequency is not within the range of the data.

  {
    int itest=static_cast<int>( round( (f-f0val)/dfval ) );
    if(itest<0)
    {
      throw mspass::utility::MsPASSError(
        "BasicSpectrum::sample_number:  f must be positive or greater than f0 if f0!=0",
        mspass::utility::ErrorSeverity::Fatal);
    }
    else if(itest>=this->nf())
    {
      throw mspass::utility::MsPASSError(
        "BasicSpectrum::sample_number:  f received exceeds the length of stored vector",
        mspass::utility::ErrorSeverity::Fatal);
    }
    else
    {
      return itest;
    }
  };

set_df()

void mspass::seismic::BasicSpectrum::set_df ( const double  dfin )

inline

Setter for the frequency bin interval - use with caution.

{dfval=dfin;};

set_dt()

void mspass::seismic::BasicSpectrum::set_dt ( const double  dtin )

inline

Setter for internally stored parent data sample interval.

{parent_dt=dtin;};

set_f0()

void mspass::seismic::BasicSpectrum::set_f0 ( const double  f0in )

inline

Setter for the initial frequency value.

{f0val=f0in;};

set_live()

void mspass::seismic::BasicSpectrum::set_live ( )

inline

Mark this datum good..

Returns true if the data are marked as being good. This method is part of a four methods for handling the concept of "live"==gppd versus "dead" == bad. The concept was borrowed from seismic reflection processing.

{is_live=true;};

set_npts()

void mspass::seismic::BasicSpectrum::set_npts ( const int  npts_in )

inline

Setter for internal parent number of data points (need by rayleigh method). Note one should only use this in constructors and when creating an instance from pieces.

{parent_npts=npts_in;};

timeseries_npts()

int mspass::seismic::BasicSpectrum::timeseries_npts ( ) const

inline

Return number of points in parent time series. Of use mostly internally.

  {
    return parent_npts;
  }

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The documentation for this class was generated from the following file:

• /home/runner/work/mspass/mspass/cxx/include/mspass/seismic/BasicSpectrum.h