Package cedar.hepdata.util

Classes
class	HDErrorNormException
	HepData exception relating to Error normalization. More...
class	HDException
	Generic HepData exception: may be a wrapper round another exception. More...
class	HDUnitException
	HepData exception relating to Unit conversions and other wranglings. More...
class	HDUtil
	General utilities for use with all HepData packages. More...
class	Unit
	A Unit is a combination of base unit terms, with a preferred power of 1000 multiple of the base unit for each term. More...
class	UnitTerm
	Representation of a term in a unit, expressed in terms of a scalefactor relative to a BaseUnit, and the power to which that base unit is raised. More...
Enumerations
enum	BaseUnit
	A semi-fundamental unit, expressed in terms of enums for particle physics units. More...
enum	SiPrefix
	SI prefixes as enums. More...

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Enumeration Type Documentation

enum BaseUnit

A semi-fundamental unit, expressed in terms of enums for particle physics units.

This enum represents base units in a fairly abstract and uncomplicated form: these enums are used to identify terms in a units expression rather than to store numbers.

The base units are partially based on the CLHEP unit choices, with the exception that eV is used rather than MeV. The main reason for this choice is to pick suitable units without prefixes as the base units, and anyway there's confusion between the Fortran and C++ eras when it comes to the energy base units so we may as well add to the melee :-)

A word is probably helpful about some of the odder base units:

• clight: c_light is usually dimensionless in HEP, but is needed for E, m, p comparisions using eV-type base units. Should render as an italic (math mode) or .
• number: Optional declaration of dimensionless number. Will be ignored in unit comparisons. Renders as "num".
• radian and degree: Of course, strictly speaking angular measurements are dimensionless, but in practice the unit matters. It would be nice to just be able to use radians as an angular base unit, but since the conversion factor is , doing on the fly conversions between radians and degrees would be pretty suicidal from a numerical hygiene point of view. The conversion and comparison routines automatically deal with these angular unit conversions. Another good reason to bin measurements in e.g. cos{}...

Enumerator:

EV
BARN
METRE
SECOND
CLIGHT
NUMBER
RADIAN
DEGREE

Definition at line 27 of file BaseUnit.java.

                     {
    EV     ("eV"),
    BARN   ("b"),
    METRE  ("m"),
    SECOND ("s"),
    CLIGHT ("c"),
    NUMBER ("num"),
    RADIAN ("rad"),
    DEGREE ("deg");
    //    STERADIAN ("sr");
    private final String name;
    BaseUnit(String name) { this.name = name; }
    public String toString() { return name; }
    public String toHtmlString() { return toString(); }
}

enum SiPrefix

SI prefixes as enums.

Enumerator:

YOTTA
ZETTA
EXA
PETA
TERA
GIGA
MEGA
KILO
UNIT
MILLI
MICRO
NANO
PICO
FEMTO
ATTO
ZEPTO
YOCTA

Definition at line 6 of file SiPrefix.java.

                     {
    YOTTA (24,  "Y", "Y"),
    ZETTA (21,  "Z", "Z"),
    EXA   (18,  "E", "E"),
    PETA  (15,  "P", "P"),
    TERA  (12,  "T", "T"),
    GIGA  (9,   "G", "G"),
    MEGA  (6,   "M", "M"),
    KILO  (3,   "k", "k"),
    UNIT  (0,   "",  ""),
    MILLI (-3,  "m", "m"),
    MICRO (-6,  "u", "µ"),
    NANO  (-9,  "n", "n"),
    PICO  (-12, "p", "p"),
    FEMTO (-15, "f", "f"),
    ATTO  (-18, "a", "a"),
    ZEPTO (-21, "z", "z"),
    YOCTA (-24, "y", "y");
    private final Integer powerOf10;
    private final String asciirep;
    private final String htmlrep;
    //private final String texrep;
    SiPrefix(Integer powerOf10, String asciirep, String htmlrep) {
        this.powerOf10 = powerOf10;
        this.asciirep = asciirep;
        this.htmlrep = htmlrep;
    }
    public Integer powerOf10() { return powerOf10; }
    public String toString() { return asciirep; }
    public String toHtmlString() { return htmlrep; }
}