Package edu.nrao.sss.measure

Measurements and their units.

See:
Description

Class Summary

Angle	An angle, or measure of arc.
AngleSortKey	A sort key and comparator that works with angles.
AngularVelocity	A measure of angular velocity.
AngularVelocityUnits	Units of angular velocity.
Distance	A measure of distance or length.
EquatorialArc<A extends EquatorialArc<A>>	An arc of either latitude or longitude on a sphere.
EquatorialArcSortKey<A extends EquatorialArc<A>>	A sort key and comparator that works with equatorial arcs, such as latitude or longitude.
FluxDensity	A measure of flux density.
Frequency	A measure of frequency.
FrequencyRange	A range of frequencies.
FrequencySpectrum	A collection of disjoint (non-overlapping, non-contiguous) frequency ranges.
JulianDate	A Julian Date.
Latitude	The latitudinal coordinate of a point on a sphere.
LinearVelocity	A measure of linear velocity.
LinearVelocityUnits	Units of linear velocity.
LocalSiderealTime	Local sidereal time (LST).
Longitude	The longitudal coordinate of a point on a sphere.
LongitudeInterval	An interval from one line of longitude to another.
TimeDuration	A length of time without a defined starting or ending point.
TimeInterval	An interval from one point in time to another.
TimeOfDay	A time of day.
TimeOfDayInterval	An interval from one time of day to another.
Wave	A wave with properties of velocity, wavelength, and frequency.

Enum Summary

ArcUnits	Units of arc.
DistanceUnits	Units of distance or length.
FluxDensityUnits	Units of measure for flux densities.
FrequencyUnits	Units of measure for frequencies.
TimeUnits	Units of time.

Package edu.nrao.sss.measure Description

Measurements and their units. Examples of measurements: distance, velocity, frequency.

Upcoming Work

Java's primitive double gives 15-16 significant digits of accuracy. This is often not enough to have us convert a measure from units A to B and back to A and land on the exact same value. Some of these classes have started to use the BigDecimal class in an effort to gain more accuracy. Note, though, that if any part of the process goes through double, the fact that BigDecimal was used internally is not enough to guarantee complete accuracy. The thing to do is convert from text Strings to BigDecimal and back. We should consider eliminating the doubles used in these classes, or to at least limiting their usages to very limited areas.

Since:

2006-05-26

Author:

David M. Harland