org.gridfour.gvrs

Class GvrsElementFloat

java.lang.Object

org.gridfour.gvrs.GvrsElement

org.gridfour.gvrs.GvrsElementFloat

public class GvrsElementFloat
extends GvrsElement

Provides a concrete definition of the GvrsElement class to access four-byte floating-point data elements.

Method Summary

Modifier and Type	Method and Description
float	getFillValue() Gets the value that is assigned to all raster cells that have not been otherwise populated.
float	getMaxValue() Gets the maximum value specified for the range of this instance.
float	getMinValue() Gets the minimum value specified for the range of this instance.
float	readValue(GridPoint gridPoint) Reads a floating-point value from the GVRS raster file.
float	readValue(int row, int column) Reads a floating-point value from the GVRS raster file.
int	readValueInt(GridPoint gridPoint) Reads an integer value from the GVRS raster file.
int	readValueInt(int row, int column) Read an integer value from the GvrsFile.
String	toString()
void	writeValue(GridPoint gridPoint, float value) Write a floating-point value to the GVRS raster file.
void	writeValue(int row, int col, float value) Write a floating-point value to the GVRS raster file.
void	writeValueInt(GridPoint gridPoint, int value) Write an integer value in the GVRS raster file.
void	writeValueInt(int row, int column, int value) Write an integer value in the GVRS raster file.

Methods inherited from class org.gridfour.gvrs.GvrsElement

getDataType, getDescription, getLabel, getName, getUnitOfMeasure, isContinuous, readBlock, readBlockInt

Methods inherited from class java.lang.Object

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

Method Detail

readValueInt

public int readValueInt(int row,
                        int column)
                 throws IOException

Read an integer value from the GvrsFile. If no data exists for the specified row and column, the fill value will be returned.

Specified by:

readValueInt in class GvrsElement

Parameters:

row - a positive value in the range defined by the file specifications.

column - a positive value in the range defined by the file specifications.

Returns:

an integer value.

Throws:

IOException - in the event of a non-recoverable I/O exception.

readValueInt

public int readValueInt(GridPoint gridPoint)
                 throws IOException

Description copied from class: GvrsElement

Reads an integer value from the GVRS raster file. If no data exists for the coordinates (row and column) specified by the GridPoint instance, the fill value will be returned.

Specified by:

readValueInt in class GvrsElement

Parameters:

gridPoint - a valid instance

Returns:

an integer value stored at the specified row and column

Throws:

IOException - in the event of a non-recoverable I/O exception.

writeValueInt

public void writeValueInt(int row,
                          int column,
                          int value)
                   throws IOException

Description copied from class: GvrsElement

Write an integer value in the GVRS raster file. Because write operations are buffered, this data may be retained in memory for some time before actually being written to the file. However, any data lingering in memory will be recorded when the flush() or close() methods are called.

The value GvrsFileConstants.NULL_DATA_CODE is reserved for the representation of null data.

Specified by:

writeValueInt in class GvrsElement

Parameters:

row - a positive value in the range defined by the file specifications.

column - a positive value in the range defined by the file specifications.

value - an integer value.

Throws:

IOException - in the event of an unrecoverable I/O exception.

readValue

public float readValue(GridPoint gridPoint)
                throws IOException

Description copied from class: GvrsElement

Reads a floating-point value from the GVRS raster file. If no data exists for the coordinates (row and column) specified by the GridPoint instance, the fill value will be returned.

Specified by:

readValue in class GvrsElement

Parameters:

gridPoint - a valid instance

Returns:

an floating-point value or the fill value if there is no data stored at the specified row and column

Throws:

IOException - in the event of a non-recoverable I/O exception.

readValue

public float readValue(int row,
                       int column)
                throws IOException

Description copied from class: GvrsElement

Reads a floating-point value from the GVRS raster file. If no data exists for the specified row and column, the fill value will be returned.

Specified by:

readValue in class GvrsElement

Parameters:

row - a positive value in the range defined by the file specifications.

column - a positive value in the range defined by the file specifications.

Returns:

an floating-point value or the fill value if there is no data stored at the specified row and column

Throws:

IOException - in the event of a non-recoverable I/O exception.

writeValue

public void writeValue(int row,
                       int col,
                       float value)
                throws IOException

Description copied from class: GvrsElement

Write a floating-point value to the GVRS raster file. Because write operations are buffered, this data may be retained in memory for some time before actually being written to the file. However, any data lingering in memory will be recorded when the flush() or close() methods are called.

The value Float.NaN is reserved for the representation of null data.

Specified by:

writeValue in class GvrsElement

Parameters:

row - a positive value in the range defined by the file specifications.

col - a positive value in the range defined by the file specifications.

value - an floating-point value.

Throws:

IOException - in the event of an unrecoverable I/O exception.

writeValue

public void writeValue(GridPoint gridPoint,
                       float value)
                throws IOException

Description copied from class: GvrsElement

Write a floating-point value to the GVRS raster file. Because write operations are buffered, this data may be retained in memory for some time before actually being written to the file. However, any data lingering in memory will be recorded when the flush() or close() methods are called.

The value Float.NaN is reserved for the representation of null data.

Specified by:

writeValue in class GvrsElement

Parameters:

gridPoint - a valid instance giving coordinates within the limits of the grid.

value - an floating-point value.

Throws:

IOException - in the event of an unrecoverable I/O exception.

writeValueInt

public void writeValueInt(GridPoint gridPoint,
                          int value)
                   throws IOException

Description copied from class: GvrsElement

Write an integer value in the GVRS raster file. Because write operations are buffered, this data may be retained in memory for some time before actually being written to the file. However, any data lingering in memory will be recorded when the flush() or close() methods are called.

The value GvrsFileConstants.NULL_DATA_CODE is reserved for the representation of null data.

Specified by:

writeValueInt in class GvrsElement

Parameters:

gridPoint - a valid instance giving coordinates within the dimensions of the grid.

value - an integer value.

Throws:

IOException - in the event of an unrecoverable I/O exception.

toString

public String toString()

Overrides:

toString in class GvrsElement

getFillValue

public float getFillValue()

Gets the value that is assigned to all raster cells that have not been otherwise populated. Some data sources may treat this value as a "no-data" value while others may treat it as a meaningful default value. The fill value is specified when a GVRS file is first created and may not be modified afterwards.

The fill value is not required to be within the range specified by the minimum and maximum values.

Returns:

an arbitrary floating-point value, including not-a-number and positive or negative infinity.

getMaxValue

public float getMaxValue()

Gets the maximum value specified for the range of this instance. The maximum value is specified when a GVRS file is first created and may not be modified afterwards.

Returns:

an arbitrary floating-point value, including positive infinity but not negative infinity or not-a-number.

getMinValue

public float getMinValue()

Gets the minimum value specified for the range of this instance. The minimum value is specified when a GVRS file is first created and may not be modified afterwards.

Returns:

an arbitrary floating-point value, including negitive infinity but not positive infinity or not-a-number