S=[1 0 -1 0];  xsD=xsS;  ysD=[3/4 1/4 -5/4 1/4];
  warp = tpsGetWarp( 0, xsS, ysS, xsD, ysD );
  [gxs, gys] = meshgrid(-1.25:.25:1.25,-1.25:.25:1.25);
  tpsInterpolate( warp, gxs, gys, 1 );

 EXAMPLE - 2
  xsS = [3.6929 6.5827 6.7756 4.8189 5.6969];
  ysS = [10.3819 8.8386 12.0866 11.2047 10.0748];
  xsD = [3.9724 6.6969 6.5394 5.4016 5.7756];
  ysD = [6.5354 4.1181 7.2362 6.4528 5.1142];
  warp = tpsGetWarp( 0, xsS, ysS, xsD, ysD );
  [gxs, gys] = meshgrid(3.5:.25:7, 8.5:.25: 12.5);
  tpsInterp