org.esa.snap.core.dataop.barithm

Class BandArithmetic

java.lang.Object

org.esa.snap.core.dataop.barithm.BandArithmetic

public class BandArithmetic
extends Object

Provides band arithmetic utility methods.

Method Summary

Modifier and Type	Method and Description
static boolean	areRastersEqualInSize(Product[] products, int defaultProductIndex, String... expressions) Determines whether all rasters which are referenced in the given expressions are compatible.
static boolean	areRastersEqualInSize(Product product, String... expressions) Determines whether all rasters which are referenced in the given expressions are compatible.
static boolean	areRastersEqualInSize(Term term) Determines whether all rasters which are referenced in a term are compatible.
static WritableNamespace	createDefaultNamespace(Product[] products, int contextProductIndex) Creates a default namespace for the product(s) given in an array.
static WritableNamespace	createDefaultNamespace(Product[] products, int contextProductIndex, ProductNamespacePrefixProvider... prefixProviders) Creates a default namespace for the product(s) given in an array.
static String	createExternalName(String name) Create an external name from the given name.
static void	deregisterFunction(Function f) De-registers an existing global function.
static void	deregisterSymbol(Symbol s) De-registers an existing global symbol.
static String	getProductNodeNamePrefix(Product product) Gets a symbol name prefix for the names of bands, tie point grids, flags, etc. of the given product.
static RasterDataSymbol[]	getRefRasterDataSymbols(Term... terms) Utility method which returns all raster data symbols referenced in a given compiled band math expressions.
static RasterDataNode[]	getRefRasters(String expression, Product... products) Utility method which returns all raster data nodes referenced in the given band math expressions.
static RasterDataNode[]	getRefRasters(String expression, Product[] products, int contextProductIndex) Utility method which returns all raster data nodes referenced in the given band math expressions.
static RasterDataNode[]	getRefRasters(Term... terms) Utility method which returns all raster data nodes referenced in the given compiled band math expressions.
static String	getValidMaskExpression(String expression, Product[] products, int contextProductIndex, String validMaskExpression)
static String	getValidMaskExpression(String expression, Product product, String validMaskExpression)
static Term	parseExpression(String expression, Product contextProduct) Parses the given expression.
static Term	parseExpression(String expression, Product[] products, int contextProductIndex) Parses the given expression.
static void	registerFunction(Function f) Registers a new global function.
static void	registerSymbol(Symbol s) Registers a new global symbol.

Methods inherited from class java.lang.Object

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

Method Detail

registerSymbol

public static void registerSymbol(Symbol s)

Registers a new global symbol.

Parameters:

s - the symbol

deregisterSymbol

public static void deregisterSymbol(Symbol s)

De-registers an existing global symbol.

Parameters:

s - the symbol

registerFunction

public static void registerFunction(Function f)

Registers a new global function.

Parameters:

f - the function

deregisterFunction

public static void deregisterFunction(Function f)

De-registers an existing global function.

Parameters:

f - the function

parseExpression

public static Term parseExpression(String expression,
                                   Product contextProduct)
                            throws ParseException

Parses the given expression.

Parameters:

expression - the expression

contextProduct - the context product

Returns:

the compiled expression

Throws:

ParseException - if a parse error occurs

parseExpression

public static Term parseExpression(String expression,
                                   Product[] products,
                                   int contextProductIndex)
                            throws ParseException

Parses the given expression.

Parameters:

expression - the expression

products - the array of source products which form the valid namespace for the expression

contextProductIndex - the index of the context product for which also symbols without the product prefix $ref-no are registered in the namespace

Returns:

the compiled expression

Throws:

ParseException - if a parse error occurs

createDefaultNamespace

public static WritableNamespace createDefaultNamespace(Product[] products,
                                                       int contextProductIndex)

Creates a default namespace for the product(s) given in an array. The resulting namespace contains symbols for all tie-point grids, bands and single flag values. if the array contains more then one product, the symbol's name will have a prefix according to each product's reference number.

Parameters:

products - the array of source products which form the valid namespace for the expression

contextProductIndex - the index of the context product for which also symbols without the product prefix $ref-no are registered in the namespace

Returns:

a default namespace, never null

createDefaultNamespace

public static WritableNamespace createDefaultNamespace(Product[] products,
                                                       int contextProductIndex,
                                                       ProductNamespacePrefixProvider... prefixProviders)

Creates a default namespace for the product(s) given in an array. The resulting namespace contains symbols for all tie-point grids, bands and single flag values. if the array contains more then one product, the symbol's name will have a prefix according to each product's reference number.

Parameters:

products - the array of source products which form the valid namespace for the expression

contextProductIndex - the index of the context product for which also symbols without the product prefix $ref-no are registered in the namespace

prefixProviders - a list of product prefix providers

Returns:

a default namespace, never null

getRefRasters

public static RasterDataNode[] getRefRasters(String expression,
                                             Product... products)
                                      throws ParseException

Utility method which returns all raster data nodes referenced in the given band math expressions.

Parameters:

expression - the expression

products - the array of source products which form the valid namespace for the expression

Returns:

the array of raster data nodes, which may be empty

Throws:

ParseException

getRefRasters

public static RasterDataNode[] getRefRasters(String expression,
                                             Product[] products,
                                             int contextProductIndex)
                                      throws ParseException

Utility method which returns all raster data nodes referenced in the given band math expressions.

Parameters:

expression - the expression

products - the array of source products which form the valid namespace for the expression

contextProductIndex - the index of the context product for which also symbols without the product prefix $ref-no are registered in the namespace

Returns:

the array of raster data nodes, which may be empty

Throws:

ParseException

getRefRasters

public static RasterDataNode[] getRefRasters(Term... terms)

Utility method which returns all raster data nodes referenced in the given compiled band math expressions.

Parameters:

terms - the array of terms to be analysed

Returns:

the array of raster data nodes, which may be empty

getRefRasterDataSymbols

public static RasterDataSymbol[] getRefRasterDataSymbols(Term... terms)

Utility method which returns all raster data symbols referenced in a given compiled band math expressions. The order of the returned rasters is the order they appear in the given terms.

Parameters:

terms - the compiled band math expressions

Returns:

the array of raster data symbols, never null but may be empty

getValidMaskExpression

public static String getValidMaskExpression(String expression,
                                            Product product,
                                            String validMaskExpression)
                                     throws ParseException

Throws:

ParseException

getValidMaskExpression

public static String getValidMaskExpression(String expression,
                                            Product[] products,
                                            int contextProductIndex,
                                            String validMaskExpression)
                                     throws ParseException

Throws:

ParseException

createExternalName

public static String createExternalName(String name)

Create an external name from the given name. If the given name contains character which are not valid in an external name the name is escaped with single quotes.

The method simply delgates to Tokenizer.createExternalName(String).

Parameters:

name - the name

Returns:

a valid external name

getProductNodeNamePrefix

public static String getProductNodeNamePrefix(Product product)

Gets a symbol name prefix for the names of bands, tie point grids, flags, etc. of the given product. The prefix is of the general form "$refNo." where refNo is the product's reference number returned by Product.getRefNo().

Parameters:

product - the product, must not be null

Returns:

a node name prefix, never null.

areRastersEqualInSize

public static boolean areRastersEqualInSize(Term term)

Determines whether all rasters which are referenced in a term are compatible.

Parameters:

term - The term in question

Returns:

true if the rasters are compatible

areRastersEqualInSize

public static boolean areRastersEqualInSize(Product product,
                                            String... expressions)
                                     throws ParseException

Determines whether all rasters which are referenced in the given expressions are compatible.

Parameters:

product - The product to which the expressions can refer

expressions - the expressions in question

Returns:

true if all referenced rasters are compatible

Throws:

ParseException - if a parse error occurs

areRastersEqualInSize

public static boolean areRastersEqualInSize(Product[] products,
                                            int defaultProductIndex,
                                            String... expressions)
                                     throws ParseException

Determines whether all rasters which are referenced in the given expressions are compatible.

Parameters:

products - The product to which the expressions can refer

defaultProductIndex - The index of the default product

expressions - the expressions in question

Returns:

true if all referenced rasters are compatible

Throws:

ParseException - if a parse error occurs