% help for MEXfile  corners2r.c                            Steve Mann, 1992
%                  (corners2r.m is comments only) 
%
% converts 4 corners for rechirp to the reqired p-chirp parameters
% so that the 4 corners can be put at the specified points
%
% user supplies [u1,v1, u2,v2, u3,v3, u4,v4];
% and this function returns [a_inv,b_inv,c_inv,d_inv,e_inv,f_inv,g_inv,h_inv]
%
% Right now user must supply a vector containing the 8 point parameters, and
% this function returns a vector containing the 8 p-chirp parameters.
% At present the user cannot supply 8 separate input parameters to get back
% 8 separate output parameters as with corners2d.m
%
% Note that identity on RHS (corners) is [0,0  0,1  1,0  1,1]
% while the identity on the RHS (p-chirp parameters) is [1 0 0 0 1 0 0 0]
%
% See also: corners2d.m, pcompose.m, pchirp.c (help in pchirp.m)
%
% Example: corners=[72/203,0, 0,319/320, 146/203,1/320, 202/203,307/320]
%          p=corners2r(corners)
%          y=pchirp2(p,red);