Class FITSWCS.projections.CSCProjection
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Class FITSWCS.projections.CSCProjection

java.lang.Object
   |
   +----FITSWCS.Projection
           |
           +----FITSWCS.projections.CSCProjection

public class CSCProjection
extends Projection
This class provides support for the COBE quadrilateralized spherical cube projection (CSC) used by the FITS "World Coordinate System" (WCS) convention.

The FITSWCS package was translated from the WCSLIB C library. This original library was written in support for coordinate systems used by astronomical data stored in FITS format. For more information on these coordinate systems, refer to the paper by Greisen and Calabretta at:

ftp://fits.cv.nrao.edu/fits/documents/wcs/wcs.all.ps.Z
Nomenclature

In WCSLIB the "forward" direction is from (lng,lat) celestial coordinates to (x,y) coordinates in the plane of projection. This accords with the notion that spherical projections are a projection of the sphere onto a plane, the "reverse" direction is therefore that of deprojection from plane to sphere.

Unfortunately, this is opposite to what is generally understood to be the forward direction for FITS, namely that of transforming pixel coordinates to world coordinates. However, the ordering of function argument lists should make it clear what is intended.

Accuracy

Closure to a precision of at least 1.0-10 degree of longitude and latitude has been verified for typical projection parameters on the 1 degree grid of native longitude and latitude (to within 5 degrees of any latitude where the projection may diverge). Notwithstanding this, absolutely no claim is made for the accuracy or reliability of these routines. They are supplied as is, with no warranty of fitness for any purpose.


COPYRIGHT NOTICE

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details.

You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

Correspondence concerning WCSLIB may be directed to:

     Internet email: mcalabre@atnf.csiro.au
     Postal address: Dr. Mark Calabretta,
                     Australia Telescope National Facility,
                     P.O. Box 76,
                     Epping, NSW, 2121,
                     AUSTRALIA
Correspondence concerning the Java implementation may be directed to Raymond L. Plante (rplante@ncsa.uiuc.edu).

Variable Index

 o c00
 o c01
 o c02
 o c10
 o c11
 o c20
 o d0
 o d1
 o gamma
 o gstar
 o mm
 o omega1
 o p00
 o p01
 o p02
 o p03
 o p04
 o p05
 o p06
 o p10
 o p11
 o p12
 o p13
 o p14
 o p15
 o p20
 o p21
 o p22
 o p23
 o p24
 o p30
 o p31
 o p32
 o p33
 o p40
 o p41
 o p42
 o p50
 o p51
 o p60
 o tol

Constructor Index

 o CSCProjection()
Create an CSCProjection object
 o CSCProjection(double)
Create an CSCProjection object
 o CSCProjection(double, double[])
Create an CSCProjection object
 o CSCProjection(double[])
Create an CSCProjection object

Method Index

 o fwd(double, double)
Compute (x,y) coordinates in the plane of projection from native spherical coordinates (phi,theta).
 o rev(double, double)
Compute native spherical coordinates (phi,theta) from the (x,y) coordinates in the plane of projection.
 o setProjParm(double[])
set the projection parameters (which are not used);
 o setR0(double)
set the sphere radius

Variables

 o gstar
  public final static float gstar
 o mm
  public final static float mm
 o gamma
  public final static float gamma
 o omega1
  public final static float omega1
 o d0
  public final static float d0
 o d1
  public final static float d1
 o c00
  public final static float c00
 o c10
  public final static float c10
 o c01
  public final static float c01
 o c11
  public final static float c11
 o c20
  public final static float c20
 o c02
  public final static float c02
 o tol
  protected float tol
 o p00
  public final static float p00
 o p10
  public final static float p10
 o p20
  public final static float p20
 o p30
  public final static float p30
 o p40
  public final static float p40
 o p50
  public final static float p50
 o p60
  public final static float p60
 o p01
  public final static float p01
 o p11
  public final static float p11
 o p21
  public final static float p21
 o p31
  public final static float p31
 o p41
  public final static float p41
 o p51
  public final static float p51
 o p02
  public final static float p02
 o p12
  public final static float p12
 o p22
  public final static float p22
 o p32
  public final static float p32
 o p42
  public final static float p42
 o p03
  public final static float p03
 o p13
  public final static float p13
 o p23
  public final static float p23
 o p33
  public final static float p33
 o p04
  public final static float p04
 o p14
  public final static float p14
 o p24
  public final static float p24
 o p05
  public final static float p05
 o p15
  public final static float p15
 o p06
  public final static float p06

Constructors

 o CSCProjection
  public CSCProjection()
Create an CSCProjection object
 o CSCProjection
  public CSCProjection(double r0)
Create an CSCProjection object
Parameters:
r0 - sphere radius
 o CSCProjection
  public CSCProjection(double r0,
                       double p[])
Create an CSCProjection object
Parameters:
r0 - sphere radius
p - projection parameters. None are actually used by this projection; this constructor is provided to parallel other subclasses of the Projection class
 o CSCProjection
  public CSCProjection(double p[])
Create an CSCProjection object
Parameters:
p - projection parameters. None are actually used by this projection; this constructor is provided to parallel other subclasses of the Projection class

Methods

 o fwd
  public double[] fwd(double phi,
                      double theta) throws PixelBeyondProjectionException
Compute (x,y) coordinates in the plane of projection from native spherical coordinates (phi,theta).
Returns:
double[] a two-element array containing x,y
Overrides:
fwd in class Projection
 o rev
  public double[] rev(double x,
                      double y) throws PixelBeyondProjectionException
Compute native spherical coordinates (phi,theta) from the (x,y) coordinates in the plane of projection.
Returns:
double[] a two-element array containing phi,theta
Overrides:
rev in class Projection
 o setR0
  public void setR0(double r0)
set the sphere radius
Overrides:
setR0 in class Projection
 o setProjParm
  public void setProjParm(double p[])
set the projection parameters (which are not used);
Parameters:
p - array of projection parameters; if p is null, no update is to be made.
Overrides:
setProjParm in class Projection

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