Package ucar.nc2.ogc.erddap.util

Class ErddapEDUnits

  • public class ErddapEDUnits
extends Object
    This class has static methods to convert units from one standard to another.

    • 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

      • ErddapEDUnits

        public ErddapEDUnits()

    • Method Detail

      • udunitsToUcum

        public static String udunitsToUcum​(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 String ucumToUdunits​(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 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