gov.noaa.pfel.erddap.util

Class EDUnits

java.lang.Object

gov.noaa.pfel.erddap.util.EDUnits

public class EDUnits
extends Object

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

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor and Description
EDUnits()

Method Summary

Methods

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

UDUNITS and UCUM support metric prefixes.

metricAcronym

public static String[] metricAcronym

nMetric

public static int nMetric

twoAcronym

public static String[] twoAcronym

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

twoValue

public static String[] twoValue

nTwo

public static int nTwo

Constructor Detail

EDUnits

public EDUnits()

Method Detail

udunitsToUcum

public static String udunitsToUcum(String udunits)

This converts UDUnits to UCUM.
UDUnits: http://www.unidata.ucar.edu/software/udunits/udunits-1/etc/udunits.dat http://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 String ucumToUdunits(String ucum)

This converts UCUM to UDUnits.
UDUnits: http://www.unidata.ucar.edu/software/udunits/udunits-1/etc/udunits.dat http://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 HashMap<String,String> getHashMapStringString(InputStream inputStream,
                                            String charset)
                                                     throws 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:

IOException - if an I/O error occurs