casa  5.7.0-16
casacore::PixelCurve1D Class Reference

Arbitrary 1-dim curve in a lattice plane. More...

`#include <PixelCurve1D.h>`

## Public Member Functions

PixelCurve1D (double x1=0, double y1=0, double x2=1, double y2=1, uInt npoints=0)
Define a straight line from (x1,y1) to (x2,y2). More...

PixelCurve1D (const Function1D< float, float > &, float x1, float x2, uInt npoints=0)
Define a curve with an arbitrary function from x1 to x2. More...

PixelCurve1D (const Vector< Int > &x, const Vector< Int > &y, uInt npoints=0)
Define a curve from a polyline with the given points. More...

PixelCurve1D (const Vector< float > &x, const Vector< float > &y, uInt npoints=0)

PixelCurve1D (const Vector< double > &x, const Vector< double > &y, uInt npoints=0)

PixelCurve1D (const PixelCurve1D &that)

~PixelCurve1D ()

PixelCurve1Doperator= (const PixelCurve1D &that)

uInt npoints () const

void getPixelCoord (Vector< float > &x, Vector< float > &y, uInt start, uInt end, uInt incr=1) const
Get the pixel coordinates in the original lattice for point start till end with given step. More...

## Private Member Functions

void init (const Vector< double > &x, const Vector< double > &y, uInt npoints)
Initialize the object. More...

## Private Attributes

uInt itsNpoints

Vector< double > itsX

Vector< double > itsY

## Detailed Description

Arbitrary 1-dim curve in a lattice plane.

Public interface

Test programs:
tPixelCurve1D

### Synopsis

PixelCurve1D represents a 1-dim curve in a lattice plane to be used by CurvedLattice2D. The curve can be any function supported in the Functionals module.
A special constructor exists to define a straight line.
Another special constructor exists for a polyline.

The domain for which the curve is valid is given by the interval [x1,x2]. The granularity of the domain is given by the number of points. The number of points also define the length of the new axis in the CurvedLattice2D object.

### Example

// Use function y=cos(2*pi*x) on the interval [0,2] with 5 points.
Sinusoid1D<float> fn;
PixelCurve1D pcurve2(fn, 0., 2., 5);
AlwaysAssertExit (pcurve2.npoints() == 5);
pcurve2.getPixelCoord (x, y, 0, 4);
cout << x << y << endl;

The result of x is [0, 0.5, 1, 1.5, 2]. The result of y is [1, -1, 1, -1, 1]

### Motivation

The viewer must be able to show a crosscut through an image using an arbitrary curve.

### To Do

• Maybe it is better to make itsNpoints part of CurvedLattice
• If itsNpoint is still part of this class, it is possible to precompute all possible Y values in the constructors. This may speed things up for the polyline case.

Definition at line 96 of file PixelCurve1D.h.

## Constructor & Destructor Documentation

 casacore::PixelCurve1D::PixelCurve1D ( double x1 = `0`, double y1 = `0`, double x2 = `1`, double y2 = `1`, uInt npoints = `0` )
explicit

Define a straight line from (x1,y1) to (x2,y2).

The default number of points is the length of the line.

 casacore::PixelCurve1D::PixelCurve1D ( const Function1D< float, float > & , float x1, float x2, uInt npoints = `0` )

Define a curve with an arbitrary function from x1 to x2.

The default number of points is the length of the curve. The length of the curve is determined numerically by integration of sqrt(1+sqr(df/dx)).

 casacore::PixelCurve1D::PixelCurve1D ( const Vector< Int > & x, const Vector< Int > & y, uInt npoints = `0` )

Define a curve from a polyline with the given points.

Both vectors have to be equally long and at least 2 long. The argument `npoints` defines the number of points (with regular steps) in which the curve is divided. The default is the length of the polyline.

 casacore::PixelCurve1D::PixelCurve1D ( const Vector< float > & x, const Vector< float > & y, uInt npoints = `0` )
 casacore::PixelCurve1D::PixelCurve1D ( const Vector< double > & x, const Vector< double > & y, uInt npoints = `0` )
 casacore::PixelCurve1D::PixelCurve1D ( const PixelCurve1D & that )
 casacore::PixelCurve1D::~PixelCurve1D ( )

## Member Function Documentation

 void casacore::PixelCurve1D::getPixelCoord ( Vector< float > & x, Vector< float > & y, uInt start, uInt end, uInt incr = `1` ) const

Get the pixel coordinates in the original lattice for point start till end with given step.

 void casacore::PixelCurve1D::init ( const Vector< double > & x, const Vector< double > & y, uInt npoints )
private

Initialize the object.

 uInt casacore::PixelCurve1D::npoints ( ) const
inline

Definition at line 129 of file PixelCurve1D.h.

References itsNpoints.

 PixelCurve1D& casacore::PixelCurve1D::operator= ( const PixelCurve1D & that )

## Member Data Documentation

 uInt casacore::PixelCurve1D::itsNpoints
private

Definition at line 141 of file PixelCurve1D.h.

Referenced by npoints().

 Vector casacore::PixelCurve1D::itsX
private

Definition at line 142 of file PixelCurve1D.h.

 Vector casacore::PixelCurve1D::itsY
private

Definition at line 143 of file PixelCurve1D.h.

The documentation for this class was generated from the following file: