mspass::algorithms::CosineTaper Class Reference

Taper front and/or end of a time seris with a half cosine function. More...

#include <Taper.h>

Inheritance diagram for mspass::algorithms::CosineTaper:

Collaboration diagram for mspass::algorithms::CosineTaper:

Public Member Functions
	CosineTaper (const double t0head, const double t1head, const double t1tail, const double t0tail)
	primary constructor.
int	apply (mspass::seismic::TimeSeries &d)
int	apply (mspass::seismic::Seismogram &d)
double	get_t0head () const
double	get_t1head () const
double	get_t0tail () const
double	get_t1tail () const
Public Member Functions inherited from mspass::algorithms::BasicTaper
	BasicTaper ()
virtual	~BasicTaper ()
void	enable_head ()
void	disable_head ()
void	enable_tail ()
void	disable_tail ()
bool	head_is_enabled ()
bool	tail_is_enable ()

Friends
class	boost::serialization::access

Additional Inherited Members
Protected Attributes inherited from mspass::algorithms::BasicTaper
bool	head
bool	tail
bool	all

Detailed Description

Taper front and/or end of a time seris with a half cosine function.

A sine taper is a common, simple approach to taper data. When applied at the front it defnes a half cycle of a cosine curve +1.0 in range -pi to 0. On the right it defines the same function for the range 0 to pi. The period of the left and right operator can be different. Turn off left or right by giving illegal start and end points and the operator will silently be only one sided.

Constructor & Destructor Documentation

CosineTaper() [1/2]

mspass::algorithms::CosineTaper::CosineTaper

(

)

                         {
  head = false;
  tail = false;
  all = false;
}

CosineTaper() [2/2]

mspass::algorithms::CosineTaper::CosineTaper	(	const double	t0head,
		const double	t1head,
		const double	t1tail,
		const double	t0tail
	)

primary constructor.

Defines half-cycle sine taper for front and/or back end of a time range. Zero times before t0head and after t0tail. Taper between t0head and t1head and in opposite sense from t1tail to t0tail.

                                           {
  t0head = t0h;
  t1head = t1h;
  t0tail = t0t;
  t1tail = t1t;
  if (t1head > t0head)
    head = true;
  if (t1tail < t0tail)
    tail = true;
  if (head && tail)
    all = true;
  else
    all = false;
  if (!(head || tail)) {
    stringstream ss;
    ss << "CosineTaper constructor:  illegal input.  No valid taper parameters"
       << endl
       << "Input defines front end ramp defined as 0 at " << t0h
       << " rising to 1 at " << t1h << endl
       << "Tail end ramp defined with 1 at " << t1t << " dropping to 0 at "
       << t0t << endl;
    throw MsPASSError(ss.str(), ErrorSeverity::Invalid);
  }
}

References mspass::algorithms::BasicTaper::all, mspass::algorithms::BasicTaper::head, and mspass::algorithms::BasicTaper::tail.

Member Function Documentation

apply() [1/2]

int mspass::algorithms::CosineTaper::apply ( mspass::seismic::Seismogram &  d )

virtual

Apply the cosine taper to a three-component Seismogram.

Implements mspass::algorithms::BasicTaper.

                                    {
  if (head) {
    if (d.endtime() < t0head) {
      stringstream ss;
      ss << "CosineTaper::apply:  inconsistent head taper parameters" << endl
         << "Data endtime=" << d.endtime()
         << " which is earlier than start of head taper=" << t0head << endl
         << "Data vector was not altered" << endl;
      d.elog.log_error("CosineTaper", ss.str(), ErrorSeverity::Complaint);
      return -1;
    }
    int is;
    double t, wt;
    for (t = d.t0(); t < t0head; t += d.dt()) {
      is = d.sample_number(t);
      if (is >= 0 && is < d.npts()) {
        for (int k = 0; k < 3; ++k)
          d.u(k, is) = 0.0;
      }
    }
    for (t = t0head; t < t1head; t += d.dt()) {
      is = d.sample_number(t);
      if (is >= 0) {
        wt = headcos(t0head, t1head, t);
        for (int k = 0; k < 3; ++k)
          d.u(k, is) *= wt;
      }
    }
  }
  if (tail) {
    if (d.t0() > t0tail) {
      stringstream ss;
      ss << "CosineTaper::apply:  inconsistent tail taper parameters" << endl
         << "Data start time=" << d.t0()
         << " is after the end of the tail taper = " << t0tail << endl
         << "Data vector was not altered" << endl;
      d.elog.log_error("CosineTaper", ss.str(), ErrorSeverity::Complaint);
      return -1;
    }
    int is;
    double t, wt;
    for (t = d.endtime(); t >= t0tail; t -= d.dt()) {
      is = d.sample_number(t);
      if (is >= 0 && is < d.npts()) {
        for (int k = 0; k < 3; ++k)
          d.u(k, is) = 0.0;
      }
    }
    for (t = t1tail; t < t0tail; t += d.dt()) {
      is = d.sample_number(t);
      if (is >= 0) {
        wt = tailcos(t0tail, t1tail, t);
        for (int k = 0; k < 3; ++k)
          d.u(k, is) *= wt;
      }
    }
  }
  return 0;
}

References mspass::seismic::BasicTimeSeries::dt(), mspass::utility::ProcessingHistory::elog, mspass::seismic::CoreSeismogram::endtime(), mspass::algorithms::BasicTaper::head, mspass::utility::ErrorLogger::log_error(), mspass::seismic::BasicTimeSeries::npts(), mspass::seismic::BasicTimeSeries::sample_number(), mspass::seismic::BasicTimeSeries::t0(), mspass::algorithms::BasicTaper::tail, and mspass::seismic::CoreSeismogram::u.

apply() [2/2]

int mspass::algorithms::CosineTaper::apply ( mspass::seismic::TimeSeries &  d )

virtual

Apply the cosine taper to a scalar TimeSeries.

Implements mspass::algorithms::BasicTaper.

                                    {
  if (head) {
    if (d.endtime() < t0head) {
      stringstream ss;
      ss << "CosineTaper::apply:  inconsistent head taper parameters" << endl
         << "Data endtime=" << d.endtime()
         << " which is earlier than start of head taper=" << t0head << endl
         << "Data vector was not altered" << endl;
      d.elog.log_error("CosineTaper", ss.str(), ErrorSeverity::Complaint);
      return -1;
    }
    int is;
    double t, wt;
    for (t = d.t0(); t < t0head; t += d.dt()) {
      is = d.sample_number(t);
      if (is >= 0 && is < d.npts())
        d.s[is] = 0.0;
    }
    for (t = t0head; t < t1head; t += d.dt()) {
      is = d.sample_number(t);
      if (is >= 0) {
        wt = headcos(t0head, t1head, t);
        d.s[is] *= wt;
      }
    }
  }
  if (tail) {
    if (d.t0() > t0tail) {
      stringstream ss;
      ss << "CosineTaper::apply:  inconsistent tail taper parameters" << endl
         << "Data start time=" << d.t0()
         << " is after the end of the tail taper = " << t0tail << endl
         << "Data vector was not altered" << endl;
      d.elog.log_error("CosineTaper", ss.str(), ErrorSeverity::Complaint);
      return -1;
    }
    int is;
    double t, wt;
    for (t = d.endtime(); t >= t0tail; t -= d.dt()) {
      is = d.sample_number(t);
      if (is >= 0 && is < d.npts()) {
        d.s[is] = 0.0;
      }
    }
    for (t = t1tail; t < t0tail; t += d.dt()) {
      is = d.sample_number(t);
      if (is >= 0) {
        wt = tailcos(t0tail, t1tail, t);
        d.s[is] *= wt;
      }
    }
  }
  return 0;
}

References mspass::seismic::BasicTimeSeries::dt(), mspass::utility::ProcessingHistory::elog, mspass::seismic::BasicTimeSeries::endtime(), mspass::algorithms::BasicTaper::head, mspass::utility::ErrorLogger::log_error(), mspass::seismic::BasicTimeSeries::npts(), mspass::seismic::CoreTimeSeries::s, mspass::seismic::BasicTimeSeries::sample_number(), mspass::seismic::BasicTimeSeries::t0(), and mspass::algorithms::BasicTaper::tail.

get_t0head()

double mspass::algorithms::CosineTaper::get_t0head ( ) const

inlinevirtual

Return the start time of the head taper.

Implements mspass::algorithms::BasicTaper.

{ return t0head; };

get_t0tail()

double mspass::algorithms::CosineTaper::get_t0tail ( ) const

inline

Return the zero-weight end time of the tail taper.

{ return t0tail; };

get_t1head()

double mspass::algorithms::CosineTaper::get_t1head ( ) const

inlinevirtual

Return the end time of the head taper.

Implements mspass::algorithms::BasicTaper.

{ return t1head; };

get_t1tail()

double mspass::algorithms::CosineTaper::get_t1tail ( ) const

inline

Return the one-weight start time of the tail taper.

{ return t1tail; };

---

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

• /home/runner/work/mspass/mspass/cxx/include/mspass/algorithms/Taper.h
• /home/runner/work/mspass/mspass/cxx/src/lib/algorithms/Taper.cc