triana.types

Interface Spectral

All Known Implementing Classes:

ComplexSpectrum, Spectrum, Spectrum2D, TimeFrequency

public interface Spectral

Spectral is an interface that can be implemented by any Triana data types that include data that represent frequency-domain data or that have been put through a Fourier transform. It contains methods to set and createTool relevant additional information, such as the frequency range of the data.

Spectral is consistent with the Triana model for storing spectal information, which is fully described in the documentation for the ComplexSpectrum and Spectrum types. In particular, it assumes that the object stores the value of the highest frequency contained in the data set (used for narrow-band data) but not the lowest; therefore there is a method for setting the highest frequency but not one for setting the lowest.

Spectral assumes one aspect of the GraphType data model, which is that data are organized as functions of a set of independent variables, and many of the methods of Spectrum take the integer index of the appropriate independent variable (dimension) as an argument. This allows milti-dimensional spectral data to have different properties associated with different dimensions.

See Also:

Spectrum, ComplexSpectrum, GraphType

Method Summary

Methods

Modifier and Type	Method and Description
double[]	getFrequencyArray(int dim) Returns the frequency values of the independent data points for the given dimension, in the order of lowest frequency to highest, regardless of how the data are stored internally.
double	getFrequencyResolution(int dim) Returns the frequency resolution of the data associated with the independent variable indexed by the given value of dim, i.e. the step in frequency from one data point to the next.
double	getLowerFrequencyBound(int dim) Returns the (non-negative) value of the lowest frequency in the frequency band held in the object, for the given dimension dim.
java.lang.Object	getOrderedSpectrumImag() Returns the imaginary parts of the values of the spectrum (data points) in a multidimensional array, ordered so that in each dimension the values correspond to frequencies running from the lowest to the highest, regardless of the internal data model.
java.lang.Object	getOrderedSpectrumReal() Returns the real parts of the values of the spectrum (data points) in a multidimensional array, ordered so that in each dimension the values correspond to frequencies running from the lowest to the highest, regardless of the internal data model.
int	getOriginalN(int dim) Returns the number of points in the data set whose transform could have led to the present data, or equivalently the number of points in the two-sided full-bandwidth spectrum from which the present spectrum could have been derived.
double	getUpperFrequencyBound(int dim) Returns the (non-negative) value of the highest frequency in the frequency band held in the object, for the given dimension dim.
boolean	isNarrow(int dim) Returns true if the data represent a narrow bandwidth derived from a full-band spectrum in the given dimension dim..
boolean	isTwoSided() Returns true if the data are stored as a two-sided transform, i.e. containing both the positive and negative frequency data.
void	setFrequencyResolution(double f, int dim) Sets the frequency resolution of the data associated with the independent variable indexed by the given value of dim.
void	setNarrow(boolean n, int dim) Sets the narrow-band flag for the given dimension dim to the value of the argument.
void	setOriginalN(int nOrig, int dim) Sets to the given argument the number of points in the data set whose transform could have led to the present data, or equivalently the number of points in the two-sided full-bandwidth spectrum from which the present spectrum could have been derived.
void	setTwoSided(boolean s) Sets the two-sided flag to the value of the argument.
void	setUpperFrequencyBound(double hf, int dim) Sets the (non-negative) value of the highest frequency in the frequency band held in the object for the given direction dim to the given value hf.

Method Detail

getFrequencyResolution

double getFrequencyResolution(int dim)

Returns the frequency resolution of the data associated with the independent variable indexed by the given value of dim, i.e. the step in frequency from one data point to the next.

Parameters:

dim - The index of the independent variable being queried

Returns:

double The frequency resolution

setFrequencyResolution

void setFrequencyResolution(double f,
                          int dim)

Sets the frequency resolution of the data associated with the independent variable indexed by the given value of dim.

Parameters:

dim - The index of the independent variable being queried

f - The frequency resolution

isTwoSided

boolean isTwoSided()

Returns true if the data are stored as a two-sided transform, i.e. containing both the positive and negative frequency data. If false, the data are one-sided, containing only positive frequencies. If the data set is multi-dimensional, then one-sided means that only positive frequencies for the first independent variable, dim = 0, are stored. Thus, there is no dim parameter for this method.

Returns:

boolean True if data are two-sided in frequency space

setTwoSided

void setTwoSided(boolean s)

Sets the two-sided flag to the value of the argument. As for method isTwoSided, there is no parameter dim.

Parameters:

s - True if the data will be two-sided

getOriginalN

int getOriginalN(int dim)

Returns the number of points in the data set whose transform could have led to the present data, or equivalently the number of points in the two-sided full-bandwidth spectrum from which the present spectrum could have been derived. This depends on which independent variable one is examining (dim).

Parameters:

dim - The index of the independent variable being queried

Returns:

The number of points in the original data set

setOriginalN

void setOriginalN(int nOrig,
                int dim)

Sets to the given argument the number of points in the data set whose transform could have led to the present data, or equivalently the number of points in the two-sided full-bandwidth spectrum from which the present spectrum could have been derived. For multidimensional sets this represents the length in the given dimension.

Parameters:

nOrig - The new number of points in the original data set

dim - The index of the independent variable dimension

isNarrow

boolean isNarrow(int dim)

Returns true if the data represent a narrow bandwidth derived from a full-band spectrum in the given dimension dim..

Parameters:

dim - The index of the independent variable being queried

Returns:

True if data are narrow-band

setNarrow

void setNarrow(boolean n,
             int dim)

Sets the narrow-band flag for the given dimension dim to the value of the argument.

Parameters:

n - True if the data held are narrow-band

dim - The index of the independent variable being set

getLowerFrequencyBound

double getLowerFrequencyBound(int dim)

Returns the (non-negative) value of the lowest frequency in the frequency band held in the object, for the given dimension dim.

Parameters:

dim - The index of the independent variable being queried

Returns:

The lowest frequency represented in the given direction

getUpperFrequencyBound

double getUpperFrequencyBound(int dim)

Returns the (non-negative) value of the highest frequency in the frequency band held in the object, for the given dimension dim.

Parameters:

dim - The index of the independent variable being queried

Returns:

The highest frequency represented in the given direction

setUpperFrequencyBound

void setUpperFrequencyBound(double hf,
                          int dim)

Sets the (non-negative) value of the highest frequency in the frequency band held in the object for the given direction dim to the given value hf. This should also set the isNarrow flag if the given value is not the highest value of the original-length spectrum.

Parameters:

dim - The index of the independent variable being queried

hf - The new highest frequency represented in the given direction

getFrequencyArray

double[] getFrequencyArray(int dim)

Returns the frequency values of the independent data points for the given dimension, in the order of lowest frequency to highest, regardless of how the data are stored internally.

Parameters:

dim - The dimension of the independent variable

Returns:

double[] Array of ordered frequency values

getOrderedSpectrumReal

java.lang.Object getOrderedSpectrumReal()

Returns the real parts of the values of the spectrum (data points) in a multidimensional array, ordered so that in each dimension the values correspond to frequencies running from the lowest to the highest, regardless of the internal data model. These points then correspond to the values returned by getFrequencyArray for each dimension.

Returns:

Object Multidimensional arrray of ordered spectral values

getOrderedSpectrumImag

java.lang.Object getOrderedSpectrumImag()

Returns the imaginary parts of the values of the spectrum (data points) in a multidimensional array, ordered so that in each dimension the values correspond to frequencies running from the lowest to the highest, regardless of the internal data model. These points then correspond to the values returned by getFrequencyArray for each dimension.

Returns:

Object Multidimensional arrray of ordered spectral values