ucar.nc2.grib.grib2

Class Grib2SectionGridDefinition

java.lang.Object

ucar.nc2.grib.grib2.Grib2SectionGridDefinition

public class Grib2SectionGridDefinition
extends java.lang.Object

The Grid Definition section 3 for GRIB-2 files

  Octet Contents
  1–4   Length of section in octets (nn)
  5     Number of section (3)
  6     Source of grid definition (see Code table 3.0 and Note 1)
  7–10  Number of data points
  11    Number of octets for optional list of numbers (see Note 2)
  12    Interpretation of list of numbers (see Code table 3.11)
  13–14 Grid definition template number (= N) (see Code table 3.1)
  15–xx Grid definition template (see Template 3.N, where N is the grid definition template number given in octets 13–14)
  [xx+1]–nn Optional list of numbers defining number of points (see Notes 2, 3 and 4)
 

Effectively immutable, but caching lazy gds

Since:

3/28/11

Constructor Summary

Constructors

Constructor and Description
Grib2SectionGridDefinition(byte[] rawData) Set Grib Definition section from byte array.
Grib2SectionGridDefinition(RandomAccessFile raf) Read Grib Definition section from raf.

Method Summary

Modifier and Type	Method and Description
long	calcCRC() Calculate the CRC of the entire byte array
Grib2Gds	getGDS()
int	getGDSTemplateNumber() Get GDS Template number (code table 3.1)
int	getLength()
int	getNumberPoints() octets 7-10 number of data points .
long	getOffset()
byte[]	getRawBytes() get the raw bytes of the GDS
int	getSource() octet 6 source of grid definition (Code Table 3.0) "If octet 6 is not zero, octets 15–xx (15–nn if octet 11 is zero) may not be supplied.

Methods inherited from class java.lang.Object

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

Constructor Detail

Grib2SectionGridDefinition

public Grib2SectionGridDefinition(RandomAccessFile raf)
                           throws java.io.IOException

Read Grib Definition section from raf.

Parameters:

raf - RandomAccessFile, with pointer at start of section

Throws:

java.io.IOException - on I/O error

java.lang.IllegalArgumentException - if not a GRIB-2 record

Grib2SectionGridDefinition

public Grib2SectionGridDefinition(byte[] rawData)

Set Grib Definition section from byte array.

Parameters:

rawData - the byte array

Method Detail

getRawBytes

public byte[] getRawBytes()

get the raw bytes of the GDS

Returns:

GDS as byte[]

calcCRC

public long calcCRC()

Calculate the CRC of the entire byte array

Returns:

CRC of the entire byte array

getLength

public int getLength()

getOffset

public long getOffset()

getSource

public int getSource()

octet 6 source of grid definition (Code Table 3.0) "If octet 6 is not zero, octets 15–xx (15–nn if octet 11 is zero) may not be supplied. This should be documented with all bits set to 1 (missing value) in the grid definition template number."

Returns:

source

getNumberPoints

public int getNumberPoints()

octets 7-10 number of data points .

Returns:

numberPoints

getGDSTemplateNumber

public int getGDSTemplateNumber()

Get GDS Template number (code table 3.1)

Returns:

GDS Template number.

getGDS

public Grib2Gds getGDS()