uk.ac.starlink.topcat.plot
Interface Points

All Known Subinterfaces:

PointStore

All Known Implementing Classes:

CartesianPointStore, SphericalPolarPointStore

public interface Points

Encapsulates a list of N-dimensional points in data space, perhaps with additional information about error bounds.

Since:

16 June 2004

Author:

Mark Taylor (Starlink)

Method Summary

int	getCount() Returns the number of points in this dataset.
double[][]	getErrors(int ipoint) Reads the errors for one of the stored points.
String	getLabel(int ipoint) Returns a string associated with a given point.
int	getNdim() Returns the length of the coordinate array for each point.
int	getNerror() Returns the number of error points returned for each point.
double[]	getPoint(int ipoint) Reads the coordinates of one of the stored points.
boolean	hasLabels() Indicates whether a string label is associated with some points.

Method Detail

getCount

int getCount()

Returns the number of points in this dataset.

Returns:

numer of points

getNdim

int getNdim()

Returns the length of the coordinate array for each point.

Returns:

number of coordinate values at each point

getPoint

double[] getPoint(int ipoint)

Reads the coordinates of one of the stored points. The returned array may be modified by subsequent calls to this method. The caller is also permitted to modify it.

Parameters:

ipoint - point index

Returns:

coords an ndim-element array containing point coordinates

getNerror

int getNerror()

Returns the number of error points returned for each point.

Returns:

number of error values at each point

getErrors

double[][] getErrors(int ipoint)

Reads the errors for one of the stored points. The returned value is an array of nerror double[] arrays, each of which has ndim elements and represents the coordinates of the end of an error bar. If any of these coordinate arrays is null, it represents an error bar of zero size, that is one whose end sits right on the data point. The ordering of these points is up to the user of this object, but typically they will be in pairs, e.g. (xlo,xhi, ylo,hi, ...). The content of the returned double[][] array and of its elements may be modified by subsequent calls to this method. The caller is also permitted to modify these.

Parameters:

ipoint - point index

Returns:

double[nerr][ndim] array with error extremum coordinates

hasLabels

boolean hasLabels()

Indicates whether a string label is associated with some points.

Returns:

true if getLabel(int) may return a non-null value for any point

getLabel

String getLabel(int ipoint)

Returns a string associated with a given point. May only return a non-null value if hasLabels() returns true.

Parameters:

ipoint - point index

Returns:

label associated with points