CompressComplex.h

Classes

CompressComplex -- Virtual column engine to scale a table Complex array (full description)

CompressComplexSD -- Virtual column engine to scale a table Complex array for Single Dish data (full description)

class CompressComplex : public BaseMappedArrayEngine<Complex, Int>

Interface

Public Members

CompressComplex (const String& virtualColumnName, const String& storedColumnName, Float scale, Float offset = 0)

CompressComplex (const String& virtualColumnName, const String& storedColumnName, const String& scaleColumnName, const String& offsetColumnName, Bool autoScale = True)

CompressComplex (const Record& spec)

~CompressComplex()

virtual String dataManagerType() const

virtual String dataManagerName() const

virtual Record dataManagerSpec() const

static String className()

static void registerClass()

Protected Members

CompressComplex (const CompressComplex&)

Private Members

CompressComplex& operator= (const CompressComplex&)

virtual DataManager* clone() const

Protected Members

virtual void create (uInt initialNrrow)

Private Members

virtual void prepare()

virtual void reopenRW()

virtual void addRowInit (uInt startRow, uInt nrrow)

virtual void getArray (uInt rownr, Array<Complex>& array)

virtual void putArray (uInt rownr, const Array<Complex>& array)

virtual void getSlice (uInt rownr, const Slicer& slicer, Array<Complex>& array)

virtual void putSlice (uInt rownr, const Slicer& slicer, const Array<Complex>& array)

virtual void getArrayColumn (Array<Complex>& array)

virtual void putArrayColumn (const Array<Complex>& array)

virtual void getColumnSlice (const Slicer& slicer, Array<Complex>& array)

virtual void putColumnSlice (const Slicer& slicer, const Array<Complex>& array)

virtual void scaleOnGet (Float scale, Float offset, Array<Complex>& array, const Array<Int>& target)

virtual void scaleOnPut (Float scale, Float offset, const Array<Complex>& array, Array<Int>& target)

void scaleColumnOnGet (Array<Complex>& array, const Array<Int>& target)

void scaleColumnOnPut (const Array<Complex>& array, Array<Int>& target)

Protected Members

Float getScale (uInt rownr)

Float getOffset (uInt rownr)

virtual void findMinMax (Float& minVal, Float& maxVal, const Array<Complex>& array) const

void makeScaleOffset (Float& scale, Float& offset, Float minVal, Float maxVal) const

void putPart (uInt rownr, const Slicer& slicer, const Array<Complex>& array, Float scale, Float offset)

void putFullPart (uInt rownr, const Slicer& slicer, Array<Complex>& fullArray, const Array<Complex>& partArray, Float minVal, Float maxVal)

Public Members

static DataManager* makeObject (const String& dataManagerType, const Record& spec)

Description

Review Status

Reviewed By:

UNKNOWN

Date Reviewed:

before2004/08/25

Programs:

Tests:

• tCompressComplex.cc

Prerequisite

• VirtualColumnEngine
• VirtualArrayColumn

Synopsis

• As a fixed values which is used for all arrays in the column. These values have to be given when constructing of the engine.
• As the name of a column. In this way each array in the column has its own scale and offset value. By default it uses auto-scaling (see below). Otherwise the scale and offset value in a row must be put before the array is put and should not be changed anymore.

As in FITS the scale and offset values are used as:
True_value = Stored_value * scale + offset;

An engine object should be used for one column only, because the stored column name is part of the engine. If it would be used for more than one column, they would all share the same stored column. When the engine is bound to a column, it is checked if the name of that column matches the given virtual column name.

The engine can be used for a column containing any kind of array (thus direct or indirect, fixed or variable shaped)) as long as the virtual array can be stored in the stored array. Thus a fixed shaped virtual can use a variable shaped stored, but not vice versa. A fixed shape indirect virtual can use a stored with direct arrays.

This class can also serve as an example of how to implement a virtual column engine.

Motivation

Because the engine can serve only one column, it was possible to combine the engine and the column functionality in one class.

Example

    // Create the table description and 2 columns with indirect arrays in it.
    // The Int column will be stored, while the double will be
    // used as virtual.
    TableDesc tableDesc ("", TableDesc::Scratch);
    tableDesc.addColumn (ArrayColumnDesc<Int> ("storedArray"));
    tableDesc.addColumn (ArrayColumnDesc<Complex> ("virtualArray"));
    tableDesc.addColumn (ScalarColumnDesc<Complex> ("scale"));
    tableDesc.addColumn (ScalarColumnDesc<Float> ("offset"));
    
    // Create a new table using the table description.
    SetupNewTable newtab (tableDesc, "tab.data", Table::New);
    
    // Create the array scaling engine (with auto-scale)
    // and bind it to the Complex column.
    CompressComplex scalingEngine("virtualArray", "storedArray",
                                  "scale", "offset");
    newtab.bindColumn ("virtualArray", scalingEngine);
    // Create the table.
    Table table (newtab);
    
    // Store a 3-D array (with dim. 2,3,4) into each row of the column.
    // The shape of each array in the column is implicitly set by the put
    // function. This will also set the shape of the underlying Int array.
    ArrayColumn data (table, "virtualArray");
    Array<double> someArray(IPosition(4,2,3,4));
    someArray = 0;
    for (uInt i=0, i<10; i++) {          // table will have 10 rows
        table.addRow();
        data.put (i, someArray)
    }
    

Member Description

CompressComplex (const String& virtualColumnName, const String& storedColumnName, Float scale, Float offset = 0)

CompressComplex (const String& virtualColumnName, const String& storedColumnName, const String& scaleColumnName, const String& offsetColumnName, Bool autoScale = True)

Construct an engine to scale the arrays in a column. The scale and offset values are taken from a column with the given names. In that way each array has its own scale factor and offset value. An exception is thrown if these columns do not exist. VirtualColumnName is the name of the virtual column and is used to check if the engine gets bound to the correct column. StoredColumnName is the name of the column where the scaled data will be put and must have data type Int. The virtual column using this engine must have data type Complex.

CompressComplex (const Record& spec)

Construct from a record specification as created by getmanagerSpec().

~CompressComplex()

Destructor is mandatory.

virtual String dataManagerType() const

Return the type name of the engine (i.e. its class name).

virtual String dataManagerName() const

Get the name given to the engine (is the virtual column name).

virtual Record dataManagerSpec() const

Record a record containing data manager specifications.

static String className()

Return the name of the class. This includes the names of the template arguments.

static void registerClass()

Register the class name and the static makeObject "constructor". This will make the engine known to the table system.

CompressComplex (const CompressComplex&)

CompressComplex& operator= (const CompressComplex&)

virtual DataManager* clone() const

Clone the engine object.

virtual void create (uInt initialNrrow)

virtual void prepare()

virtual void reopenRW()

Reopen the engine for read/write access. It makes the column writable if the underlying column is writable.

virtual void addRowInit (uInt startRow, uInt nrrow)

Add rows to the table. If auto-scaling, it initializes the scale column with 0 to indicate that no data has been processed yet.

virtual void getArray (uInt rownr, Array<Complex>& array)

Get an array in the given row. This will scale and offset from the underlying array.

virtual void putArray (uInt rownr, const Array<Complex>& array)

Put an array in the given row. This will scale and offset to the underlying array.

virtual void getSlice (uInt rownr, const Slicer& slicer, Array<Complex>& array)

Get a section of the array in the given row. This will scale and offset from the underlying array.

virtual void putSlice (uInt rownr, const Slicer& slicer, const Array<Complex>& array)

Put into a section of the array in the given row. This will scale and offset to the underlying array.

virtual void getArrayColumn (Array<Complex>& array)

Get an entire column. This will scale and offset from the underlying array.

virtual void putArrayColumn (const Array<Complex>& array)

Put an entire column. This will scale and offset to the underlying array.

virtual void getColumnSlice (const Slicer& slicer, Array<Complex>& array)

Get a section of all arrays in the column. This will scale and offset from the underlying array.

virtual void putColumnSlice (const Slicer& slicer, const Array<Complex>& array)

Put a section of all arrays in the column. This will scale and offset to the underlying array.

virtual void scaleOnGet (Float scale, Float offset, Array<Complex>& array, const Array<Int>& target)

Scale and/or offset target to array. This is meant when reading an array from the stored column. It optimizes for scale=1 and/or offset=0.

virtual void scaleOnPut (Float scale, Float offset, const Array<Complex>& array, Array<Int>& target)

Scale and/or offset array to target. This is meant when writing an array into the stored column. It optimizes for scale=1 and/or offset=0.

void scaleColumnOnGet (Array<Complex>& array, const Array<Int>& target)

Scale and/or offset target to array for the entire column. When the scale and offset are fixed, it will do the entire array. Otherwise it iterates through the array and applies the scale and offset per row.

void scaleColumnOnPut (const Array<Complex>& array, Array<Int>& target)

Scale and/or offset array to target for the entire column. When the scale and offset are fixed, it will do the entire array. Otherwise it iterates through the array and applies the scale and offset per row.

Float getScale (uInt rownr)

Float getOffset (uInt rownr)

Get the offset value for this row.

virtual void findMinMax (Float& minVal, Float& maxVal, const Array<Complex>& array) const

Find minimum and maximum from the array data. NaN and infinite values are ignored. If no values are finite, minimum and maximum are set to NaN.

void makeScaleOffset (Float& scale, Float& offset, Float minVal, Float maxVal) const

Make scale and offset from the minimum and maximum of the array data. If minVal is NaN, scale is set to 0.

void putPart (uInt rownr, const Slicer& slicer, const Array<Complex>& array, Float scale, Float offset)

Put a part of an array in a row using given scale/offset values.

void putFullPart (uInt rownr, const Slicer& slicer, Array<Complex>& fullArray, const Array<Complex>& partArray, Float minVal, Float maxVal)

Fill the array part into the full array and put it using the given min/max values.

static DataManager* makeObject (const String& dataManagerType, const Record& spec)

class CompressComplexSD : public CompressComplex

Interface

CompressComplexSD (const String& virtualColumnName, const String& storedColumnName, Float scale, Float offset = 0)

CompressComplexSD (const String& virtualColumnName, const String& storedColumnName, const String& scaleColumnName, const String& offsetColumnName, Bool autoScale = True)

CompressComplexSD (const Record& spec)

~CompressComplexSD()

virtual String dataManagerType() const

static String className()

static void registerClass()

    // Create the table description and 2 columns with indirect arrays in it.
    // The Int column will be stored, while the double will be
    // used as virtual.
    TableDesc tableDesc ("", TableDesc::Scratch);
    tableDesc.addColumn (ArrayColumnDesc<Int> ("storedArray"));
    tableDesc.addColumn (ArrayColumnDesc<Complex> ("virtualArray"));
    tableDesc.addColumn (ScalarColumnDesc<Complex> ("scale"));
    tableDesc.addColumn (ScalarColumnDesc<Float> ("offset"));
    
    // Create a new table using the table description.
    SetupNewTable newtab (tableDesc, "tab.data", Table::New);
    
    // Create the array scaling engine (with auto-scale)
    // and bind it to the Complex column.
    CompressComplexSD scalingEngine("virtualArray", "storedArray",
                                    "scale", "offset");
    newtab.bindColumn ("virtualArray", scalingEngine);
    // Create the table.
    Table table (newtab);
    
    // Store a 3-D array (with dim. 2,3,4) into each row of the column.
    // The shape of each array in the column is implicitly set by the put
    // function. This will also set the shape of the underlying Int array.
    ArrayColumn data (table, "virtualArray");
    Array<double> someArray(IPosition(4,2,3,4));
    someArray = 0;
    for (uInt i=0, i<10; i++) {          // table will have 10 rows
        table.addRow();
        data.put (i, someArray)
    }