FSpectrum

class FSpectrum

Frequency spectrum class.

Public Methods
FSpectrum(void): Default constructor.
FSpectrum(const FSpectrum& FS): Copy constructor.
FSpectrum(const FSeries& FS): Data constructor.
FSpectrum(double F0, double dF, const Time& t0, const Interval& dT, size_t nWord, float* data): Data constructor.
~FSpectrum(void): FSpectrum Destructor.
FSpectrum extract(double f0, double dF) const: Get a substring of the FSpectrum.
Time getStartTime(void) const: Get the start time.
Time getEndTime(void) const: Get the End time.
double getLowFreq(void) const: Get the minimum frequency.
double getHighFreq(void) const: Get the maximum Frequency.
double getFStep(void) const: Get the frequency step.
const char* getName(void) const: Get the spectrum name.
size_t getNStep(void) const: Get the number of frequency steps.
size_t getData(size_t len, float* data) const: Get the spectrum data.
double getSum(float f0, float dF) const: Get spectral sum.
size_t getCount(void) const: Get the number of spectra averaged.
const float* refData(void) const: Get a pointer to the spectrum data.
const DVector* refDVect(void) const: Get the data vector pointer
std::ostream& Dump(std::ostream& out) const: Dump the contents of the FSpectrum to an output stream.
void appName(const char* name): Append a string to the spectrum name.
void clear(double F0=0, double dF=0, Time t0=0, Interval dT=0.0): Clear thespectrum.
void setT0(const Time& t0): Set the start time.
void setName(const char* name): Set the spectrum name.
void setCount(size_t Count): Set the spectrum count.
void setData(size_t len, const float* data): Overwrite the spectrum with float data.
void setData(const FSeries& data): Replace spectrum with an FSeries squared.
FSpectrum& operator =(const FSpectrum& rhs): Copy a spectrum.
FSpectrum& operator +=(const FSpectrum& rhs): Add two spectra.
FSpectrum& operator -=(const FSpectrum& rhs): Subtract a spectrum.
FSpectrum& operator *=(double scale): Scale a spectrum.
double operator)(double freq) const: Get the amplitude at a specified frequency
bool isEmpty(void) const: Test for empty.

Documentation

The frequency spectrum class is used to represent a power spectrum. Although the spectrum data iscontained in a DVector, only float type data are allowed.

FSpectrum(void)

Construct an empty FSpectrum.

FSpectrum(const FSpectrum& FS)

Construct an FSpectrum and initialize it from another spectrum.

Parameters:: Constant - spectrum from which the new spectrum is initialized.

FSpectrum(const FSeries& FS)

Construct a FSpectrum and initilize it from the modulus-squared of an FSeries.

Parameters:: Frequency - series from which the spectrum is initialized

FSpectrum(double F0, double dF, const Time& t0, const Interval& dT, size_t nWord, float* data)

Construct a FSpectrum and initialize it from data.

Parameters:: F0 - Minimum frequency.
dF - Frequency step.
t0 - Start time.
dT - Time interval.
nWord - Number of data words.
data - Spectral densities.

~FSpectrum(void)

Destroy a spectrum object.

FSpectrum extract(double f0, double dF) const

Returns an FSpectrum containing a subset of the parent spectrum. The subset is specified as a starting frequency and frequency interval. No rebinning is performed, so the actual frequency range wil be rounded to the nearest bin edges.

Returns:: the extracted spectrum.
Parameters:: f0 - lowest frequency to be extracted (in Hz).
dF - Frequency interval (in Hz).

Time getStartTime(void) const

Returns the start time as specified in the source data.

Returns:: The start time of data from which the spectrum was extracted.

Time getEndTime(void) const

Returns the End time as specified in the sourrce data.

Returns:: The end time of data from which the spectrum was extracted.

double getLowFreq(void) const

Returns the minimum frequency covered by the data.

Returns:: The minimum frequency covered by the spectrum.

double getHighFreq(void) const

Returns the maximum (Nyquist) frequency of the data.

Returns:: The maximum frequency covered by the spectrum.

double getFStep(void) const

Returns the frequency interval between two adjacen spectrum points.

Returns:: THe frequency step size in Hz.

const char* getName(void) const

Returns a pointer to the spectrum name.

Returns:: pointer to the Spectrum name.

size_t getNStep(void) const

Returns the number of frequency steps. Note that the number of data points is in fact one greater than the number of steps because both the f=0 and f=Nyquist entries are included.

size_t getData(size_t len, float* data) const

Optionally convert and copy the first 'len' entries of a spectrum to a float array 'data'. getData() returns the number of entries copied.

double getSum(float f0, float dF) const

Calculate the sum of the bins in the specified frequency interval.

Returns:: the sum of all spectrum points in the frequency interval.
Parameters:: f0 - lowest frequency bin to be summed.
dF - frequency interval width.

size_t getCount(void) const