uk.ac.starlink.ttools.plot2.geom

Class SphereNet

java.lang.Object

uk.ac.starlink.ttools.plot2.geom.SphereNet

public class SphereNet
extends Object

Calculates line segments forming longitude and latitude lines for a sphere around the data origin of a cube surface.

Since:

15 Aug 2018

Author:

Mark Taylor

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SphereNet.Line3d Represents a set of 3-d points that can be joined together to make a grid line.

Constructor Summary

Constructors

Constructor and Description
SphereNet(CubeSurface surf) Constructor.

Method Summary

Modifier and Type	Method and Description
double	getDefaultRadius() Returns a reasonable radius for the sphere if none is explicitly specified.
SphereNet.Line3d[]	getLatitudeLines(double dRadius, int nLat) Returns an array of line specifications representing lines of latitude.
SphereNet.Line3d[]	getLongitudeLines(double dRadius, int nLon) Returns an array of line specifications representing lines of longitude.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SphereNet

public SphereNet(CubeSurface surf)

Constructor.

Parameters:

surf - surface on which grid lines will be specified

Method Detail

getDefaultRadius

public double getDefaultRadius()

Returns a reasonable radius for the sphere if none is explicitly specified. The general idea is to have something that will be visible. If the data origin is within the visible region, then the largest sphere that will fit is used, otherwise it's a sphere for which at least part of the surface appears in the visible region.

Returns:

reasonable radius for sphere in data units

getLongitudeLines

public SphereNet.Line3d[] getLongitudeLines(double dRadius,
                                            int nLon)

Returns an array of line specifications representing lines of longitude.

Parameters:

dRadius - radius in data units

nLon - number of equally spaced great circles required; note this is half the number of meridians

Returns:

nLon-element array of meridian specifiers

getLatitudeLines

public SphereNet.Line3d[] getLatitudeLines(double dRadius,
                                           int nLat)

Returns an array of line specifications representing lines of latitude.

Parameters:

dRadius - radius in data units

nLat - number of equally spaced latitude lines in the north (or south) hemisphere; excludes the equator

Returns:

1+nLat*2-element aray of parallel specifiers