Terapix Star Formation Region IC 1396, © 2002 CFHT
Shapelets for MATLAB
by E.B. - Updated March 23rd, 2006

This EFIGI package contains MATLAB functions for basic 2D shapelet analyses of galaxy images.

Available functions include:

% PSHAPELETS  Create a data-cube of real 2D polar shapelet basis vectors.
%     P = PSHAPELETS(width,height, nmax, beta) creates of data-cube
%     of real 2D polar shapelet basis vectors with scale beta, up to order
%     nmax. Each of the (nmax+1)(nmax+2)/2 vectors has width x height
%     pixels.

% PSHAPESHOW  Display a basis of real 2D polar shapelets.
%     PSHAPESHOW(width, height, nmax, beta) display a basis of real 2D
%     polar shapelets with widthxheight pixels and scale parameter beta,
%     up to order nmax.

% PSHAPEDEC  Decompose an image on a vector basis of 2D polar shapelets
%     [PCOEFF RIMA] = PSHAPEDEC(IMA, nmax, beta) produces a vector PCOEFF
%     of (nmax+1)(nmax+2)/2 real polar shapelet coefficients, and a
%     reconstructed image RIMA from the input image IMA. beta is the
%     scaling factor of the polar shapelets.

% PSHAPESHOWDEC  Display 2D polar shapelet reconstructed images and residuals.
%     PSHAPESHOWDEC(IMA, beta) calls PSHAPEDEC with nmax=1,2,4,8 and 16
%     and displays the reconstructed images and residuals.

Another experimental set of similar functions with SSHAPE...() replacing PSHAPE...() is available for "spiralets". Also included in this package are R. Abraham's FITSREAD() and FITSWRITE() functions providing I/O to basic FITS files.

% FITSREAD reads a FITS image into a Matlab variable.
%  data = fitsread(filename);
%  data = fitsread(filename,range);
%  data = fitsread(filename,range,scaleQ);

%FITSWRITE saves a Matlab matrix as a FITS image
%Usage: fitswrite(data, filename)

Some examples of galaxy images can be found in the samples sub- directory.

shapelet-1.0 - 260.1 kb
(GZ, 260.1 kb)
shapelet-1.0 - 264.8 kb
(Zip, 264.8 kb)

Polar shapelet basis vectors - 24.1 kb
Polar shapelet basis vectors
The first non-redundant 26 shapelet basis vectors

"Spiralet" basis vectors
The first non-redundant 26 "spiralet" basis vectors

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