ucar.nc2.grib

Class GribNumbers

java.lang.Object

ucar.nc2.grib.GribNumbers

public final class GribNumbers
extends Object

Utilities for reading and interpreting GRIB bytes.

Version:

2.0

Author:

Robb Kambic 10/20/04

Field Summary

Fields

Modifier and Type	Field and Description
static int[]	bitmask
static int	MISSING Grib uses this internal to mean missing
static int	UNDEFINED if missing value is not defined use this value.
static double	UNDEFINEDD

Constructor Summary

Constructors

Constructor and Description
GribNumbers()

Method Summary

Methods

Modifier and Type	Method and Description
static int	convertSignedByte(byte v) A signed byte has a sign bit then 1 15-bit value.
static int	convertSignedByte2(byte v)
static float	float4(int a, int b, int c, int d) Convert 4 bytes to a float.
static float	float4(RandomAccessFile raf) Convert 4 bytes into a float value.
static int	int2(int a, int b) convert 2 bytes to a signed integer.
static int	int2(RandomAccessFile raf) Convert 2 bytes into a signed integer.
static int	int3(int a, int b, int c) Convert 3 bytes to signed integer.
static int	int3(RandomAccessFile raf) Convert 3 bytes into a signed integer.
static int	int4(int a, int b, int c, int d) Convert 4 bytes into a signed integer.
static int	int4(RandomAccessFile raf) Convert 4 bytes into a signed integer.
static long	int8(RandomAccessFile raf) Convert 8 bytes into a signed long.
static boolean	isBitSet(int value, int bitMask) Is the bit set in this octet
static void	main(String[] args)
static int	uint2(int a, int b) convert 2 bytes to an unsigned integer.
static int	uint2(RandomAccessFile raf) Convert 2 bytes into an unsigned integer.
static int	uint3(int a, int b, int c) Convert 3 bytes into an unsigned int.
static int	uint3(RandomAccessFile raf) Convert 3 bytes into an unsigned integer.

Methods inherited from class java.lang.Object

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

Field Detail

UNDEFINED

public static final int UNDEFINED

if missing value is not defined use this value.

See Also:

Constant Field Values

UNDEFINEDD

public static final double UNDEFINEDD

See Also:

Constant Field Values

bitmask

public static final int[] bitmask

MISSING

public static final int MISSING

Grib uses this internal to mean missing

See Also:

Constant Field Values

Constructor Detail

GribNumbers

public GribNumbers()

Method Detail

int2

public static int int2(RandomAccessFile raf)
                throws IOException

Convert 2 bytes into a signed integer.

Parameters:

raf - read from here

Returns:

integer value

Throws:

IOException - on read error

int2

public static int int2(int a,
       int b)

convert 2 bytes to a signed integer.

Parameters:

a - first byte

b - second byte

Returns:

int

int3

public static int int3(RandomAccessFile raf)
                throws IOException

Convert 3 bytes into a signed integer.

Parameters:

raf - read from here

Returns:

integer value

Throws:

IOException - on read error

int3

public static int int3(int a,
       int b,
       int c)

Convert 3 bytes to signed integer.

Parameters:

a - first byte

b - second byte

c - third byte

Returns:

int

int4

public static int int4(RandomAccessFile raf)
                throws IOException

Convert 4 bytes into a signed integer.

Parameters:

raf - read from here

Returns:

integer value

Throws:

IOException - on read error

int4

public static int int4(int a,
       int b,
       int c,
       int d)

Convert 4 bytes into a signed integer.

Parameters:

a - first byte

b - second byte

c - third byte

d - fourth byte

Returns:

int

uint2

public static int uint2(RandomAccessFile raf)
                 throws IOException

Convert 2 bytes into an unsigned integer.

Parameters:

raf - read from here

Returns:

integer value

Throws:

IOException - on read error

uint2

public static int uint2(int a,
        int b)

convert 2 bytes to an unsigned integer.

Parameters:

a - first byte

b - second byte

Returns:

unsigned int

uint3

public static int uint3(RandomAccessFile raf)
                 throws IOException

Convert 3 bytes into an unsigned integer.

Parameters:

raf - read from here

Returns:

integer

Throws:

IOException - on read error

uint3

public static int uint3(int a,
        int b,
        int c)

Convert 3 bytes into an unsigned int.

Parameters:

a - first byte

b - second byte

c - third byte

Returns:

unsigned integer

float4

public static float float4(RandomAccessFile raf)
                    throws IOException

Convert 4 bytes into a float value.

Parameters:

raf - read from here

Returns:

float value

Throws:

IOException - on read error

float4

public static float float4(int a,
           int b,
           int c,
           int d)

Convert 4 bytes to a float.

Parameters:

a - first byte

b - second byte

c - third byte

d - fourth byte

Returns:

float

int8

public static long int8(RandomAccessFile raf)
                 throws IOException

Convert 8 bytes into a signed long.

Parameters:

raf - RandomAccessFile

Returns:

long value

Throws:

IOException - on read error

isBitSet

public static boolean isBitSet(int value,
               int bitMask)

Is the bit set in this octet

Parameters:

value - octet as an integer

bitMask - bit mask

Returns:

true if the bit is not 0

convertSignedByte

public static final int convertSignedByte(byte v)

A signed byte has a sign bit then 1 15-bit value. This is not twos complement (!)

Parameters:

v - convert byte to signed int

Returns:

signed int

convertSignedByte2

public static final int convertSignedByte2(byte v)

main

public static void main(String[] args)