MSRange.h

Classes

MSRange -- MSRange determines ranges of values in a MeasurementSet (full description)

class MSRange

Types

enum

UNCHECKED = -3,
spectral window selection and shapes have not been checked
UNSELECTED = -2,
multiple spectral windows with varying shapes multiple spectral windows with varying shapes
ALL = -1
multiple spectral windows with same shape multiple spectral windows with same shape

enum

Amp
Phase
Real
Imag
Data
nFuncType

enum

Observed
Corrected
Model
Ratio
Residual
ObsResidual
ObsFloat
nDataType

Interface

Public Members
MSRange()
explicit MSRange(const MeasurementSet& ms)
explicit MSRange(const MSSelector& msSel)
MSRange(const MSRange& other)
MSRange& operator=(const MSRange& other)
Record range(const Vector<String>& items, Bool useFlags=True, Bool OneBased=False)
Record range(const Vector<Int>& items, Bool useFlags=True, Bool OneBased=False)
Record range(MSS::Field item, Bool useFlags=True)
void setBlockSize(Int blockSize=10)
Protected Members
Bool checkShapes()
void scalarRange(Record& out, const String& item, const ROScalarColumn<Int>& id, Bool oneBased)
Vector<Int> scalarRange(const ROScalarColumn<Int>& id)
void minMax(Matrix<Float>& minmax, const Vector<Bool>& funcSel, const ROArrayColumn<Complex>& data1, const ROArrayColumn<Complex>& data2, const ROArrayColumn<Bool>& flag, Int dataType, Bool useFlags)
void minMax(Float& mini, Float& maxi, const ROArrayColumn<Float>& data, const ROArrayColumn<Bool>& flag, Bool useFlags)
Vector<Int> ifrNumbers(const ROScalarColumn<Int>& ant1, const ROScalarColumn<Int>& ant2)

Description

Review Status

Date Reviewed:
yyyy/mm/dd

Prerequisite

Etymology

MSRange is a class that determines ranges of values in an MS

Synopsis

This class is used to determine the range of values present for the various columns in a MeasurementSet. This class is initialized from a MeasurementSet. If the MS contains more than one DATA_DESC_ID, it can be preselected on this to allow a consistent set of frequencies to be returned. The ms DO provides access to this class from glish and GUIs. 

    MSRange myRange(myMS);
    Vector<String> items(3); 
    // fill in some fields
    items(0)="field_id";
    items(1)="time";
    items(2)="data_desc_id";
    // get the range of values for the items specified
    cout << myRange.range(items)<<endl;
    // sample output: range=[field_id=[0,1,2],time=[4.5e9, 4.51e9],
    //   data_desc_id=[0,1,2]];
    // Now preselect on data_desc_id
    MSSelector mss(myMS);
    Vector<Int> dd(2); dd(0)=1; dd(1)=2;
    mss.selectinit(0,dd); // select data desc ids 1 and 2
    MSRange r2(mss);
    items(2)="amplitude";
    cout<< r2.range(items)<<endl;
    // sample output: [field_id=[0,1,2],time=[4.5e9, 4.51e9],
    //   amplitude=[0.00132,1.543]]

Motivation

Finding out the range of values in a column is often needed before a sensible selection of data can be made. This class, formerly part of MSSelector, separates out this functionality.

Thrown Exceptions

To Do

Member Description

enum

MSRange()

Default constructor, only useful to assign to.

explicit MSRange(const MeasurementSet& ms)

Construct from an MS.

explicit MSRange(const MSSelector& msSel)

construct from an MSSelector, if this constructor is used, the data will be channel selected and polarization converted as specified in the MSSelector object, and the current selection is used in the range.

MSRange(const MSRange& other)

Copy constructor

MSRange& operator=(const MSRange& other)

Assignment

Record range(const Vector<String>& items, Bool useFlags=True, Bool OneBased=False)

Return the range of values for each of the items specified in the record. For index-like items a list of values is returned, for non-index items the minimum and maximum are returned. Items with varying array shape will not be returned by this function (i.e. you may need to preselect the MS passed to MSRange). See the enum description in MSSelector for the list of supported items. Use the data flags if useFlags is True. Correct for one-based indexing if oneBased is True.

Record range(const Vector<Int>& items, Bool useFlags=True, Bool OneBased=False)

Same as previous function, with Vector of MSS::Field keys instead of Strings

Record range(MSS::Field item, Bool useFlags=True)

Similar to above, with a single enum, for convenience

void setBlockSize(Int blockSize=10)

Set the block size (in Mbytes) to use when reading the data column. The default is 10 MB. Actual memory used is higher due to temporaries and caching.

Bool checkShapes()

check the data description selection (one or more with same shape, or varying shape)

void scalarRange(Record& out, const String& item, const ROScalarColumn<Int>& id, Bool oneBased)

get the range of a ScalarColumn, correct for 1-based indexing if oneBased is True, and add to out record.

Vector<Int> scalarRange(const ROScalarColumn<Int>& id)

get the range of a ScalarColumn

void minMax(Matrix<Float>& minmax, const Vector<Bool>& funcSel, const ROArrayColumn<Complex>& data1, const ROArrayColumn<Complex>& data2, const ROArrayColumn<Bool>& flag, Int dataType, Bool useFlags)

get the minimum and maximum of a Complex data column, after application of some function to convert to Float (e.g., real, amplitude,...). This function reads the data in blocks of size blockSize, as set by the setBlockSize function.

void minMax(Float& mini, Float& maxi, const ROArrayColumn<Float>& data, const ROArrayColumn<Bool>& flag, Bool useFlags)

get the minimum and maximum of a Float data column This function reads the data in blocks of size blockSize, as set by the setBlockSize function.

Vector<Int> ifrNumbers(const ROScalarColumn<Int>& ant1, const ROScalarColumn<Int>& ant2)

Get the range of interferometer numbers given the antenna1 and antenna2 columns.

enum

The function types

enum

The data types