Struct ShapeResult

Inheritance Relationships

Derived Type

Struct Documentation

struct ShapeResult

A reusable struct for moments-based shape measurements.

Shape measurements and their errors should always be in pixels coordinates. This struct should generally be preferred over a custom struct with other ellipse parametrizations unless the measurement takes place in another parametrization and a transformation to this one would result in a loss of information or obfuscate the results of the measurement (i.e. use this one unless you have a good reason not to).

Subclassed by lsst::meas::base::SdssShapeResult

Public Functions

ShapeResult()

Constructor; initializes everything to NaN.

ShapeResult(ShapeElement xx_, ShapeElement yy_, ShapeElement xy_, ShapeCov const &matrix)

Constructor; initializes everything from values.

ShapeResult(ShapeElement xx_, ShapeElement yy_, ShapeElement xy_, ErrElement xxErr_, ErrElement yyErr_, ErrElement xyErr_)

Constructor; initializes everything from values.

Shape const getShape() const

Return an afw::geom::ellipses object corresponding to xx, yy, xy.

This method can be used to return an average radius for the measured shape, e.g. getShape().getDeterminantRadius()

afw::geom::ellipses::Quadrupole getQuadrupole()
void setShape(Shape const &shape)

Set struct elements from the given Quadrupole object.

ShapeCov const getShapeErr() const

Return the 3x3 symmetric covariance matrix, with rows and columns ordered (xx, yy, xy)

void setShapeErr(ShapeCov const &matrix)

Set the struct standard deviation elements from the given matrix, with rows and columns ordered (xx, yy, xy)

void setShapeErr(ErrElement xxErr, ErrElement yyErr, ErrElement xyErr)

Set the struct standard deviation elements from the given values.

Public Members

ShapeElement xx

image or model second moment for x^2

ShapeElement yy

image or model second moment for y^2

ShapeElement xy

image or model second moment for xy^2

ErrElement xxErr

standard deviation of xx

ErrElement yyErr

standard deviation of yy

ErrElement xyErr

standard deviation of xy

ErrElement xx_yy_Cov

xx,yy term in the uncertainty convariance matrix

ErrElement xx_xy_Cov

xx,xy term in the uncertainty convariance matrix

ErrElement yy_xy_Cov

yy,xy term in the uncertainty convariance matrix