ucar.nc2.ogc.erddap.util

Class ErddapEDUnits

java.lang.Object

ucar.nc2.ogc.erddap.util.ErddapEDUnits

public class ErddapEDUnits
extends java.lang.Object

This class has static methods to convert units from one standard to another.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String[]	metricAcronym
static java.lang.String[]	metricName UDUNITS and UCUM support metric prefixes.
static int	nMetric
static int	nTwo
static java.lang.String[]	twoAcronym UCUM supports power-of-two prefixes, but UDUNITS doesn't.
static java.lang.String[]	twoValue

Constructor Summary

Constructors

Constructor and Description
ErddapEDUnits()

Method Summary

Modifier and Type	Method and Description
static java.util.HashMap<java.lang.String,java.lang.String>	getHashMapStringString(java.io.InputStream inputStream, java.lang.String charset) Reads the contents of inputStream into a HashMap.
static java.lang.String	ucumToUdunits(java.lang.String ucum) This converts UCUM to UDUnits.
static java.lang.String	udunitsToUcum(java.lang.String udunits) This converts UDUnits to UCUM.

Methods inherited from class java.lang.Object

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

Field Detail

metricName

public static java.lang.String[] metricName

UDUNITS and UCUM support metric prefixes.

metricAcronym

public static java.lang.String[] metricAcronym

nMetric

public static int nMetric

twoAcronym

public static java.lang.String[] twoAcronym

UCUM supports power-of-two prefixes, but UDUNITS doesn't.

twoValue

public static java.lang.String[] twoValue

nTwo

public static int nTwo

Constructor Detail

ErddapEDUnits

public ErddapEDUnits()

Method Detail

udunitsToUcum

public static java.lang.String udunitsToUcum(java.lang.String udunits)

This converts UDUnits to UCUM.
UDUnits: https://www.unidata.ucar.edu/software/udunits/udunits-1/etc/udunits.dat https://www.unidata.ucar.edu/software/udunits/udunits-2/udunits2.html I worked with v 2.1.9
UCUM: http://unitsofmeasure.org/ucum.html I worked with Version: 1.8, $Revision: 28894 $

UDUnits supports lots of aliases (short and long) and plurals (usually by adding 's'). These all get reduced to UCUM's short and canonical-only units.

Notes:

• This method is a strictly case sensitive. The only UDUnits that should be capitalized (other than acronyms) are Btu, Gregorian..., Julian..., PI.
  The only UDUnits that may be capitalized are Celsius, Fahrenheit, Kelvin, Rankine.
• For "10 to the", UCUM allows 10* or 10^. This method uses 10^.
• NTU becomes {ntu}.
• PSU or psu becomes {psu}.

return the UDUnits converted to UCUM. null returns null. "" returns "". throws Exception if trouble.

ucumToUdunits

public static java.lang.String ucumToUdunits(java.lang.String ucum)

This converts UCUM to UDUnits.
UDUnits: https://www.unidata.ucar.edu/software/udunits/udunits-1/etc/udunits.dat https://www.unidata.ucar.edu/software/udunits/udunits-2/udunits2.html
UCUM: http://unitsofmeasure.org/ucum.html

UCUM tends to be short, canonical-only, and strict. Many UCUM units are the same in UDUnits.

UDUnits supports lots of aliases (short and long) and plurals (usually by adding 's'). This tries to convert UCUM to a short, common UDUNIT units.

Problems:

• UCUM has only "deg", no concept of degree_east|north|true|true.

Notes:

• This method is a strictly case sensitive.
• For "10 to the", UCUM allows 10* or 10^. This method uses 10^.
• {ntu} becomes NTU.
• {psu} becomes PSU.

return the UCUM converted to UDUNITS. null returns null. "" returns "".

getHashMapStringString

public static java.util.HashMap<java.lang.String,java.lang.String> getHashMapStringString(java.io.InputStream inputStream,
                                                                                          java.lang.String charset)
                                                                                   throws java.io.IOException

Reads the contents of inputStream into a HashMap. Each key-value pair in the input will result in an entry in the map.

The specified stream remains open after this method returns.

Parameters:

inputStream - a stream with line-based, key-value pairs.

charset - the name of a supported charset.

Returns:

a HashMap initialized from the stream.

Throws:

java.io.IOException - if an I/O error occurs