Mercurial > hg > octave-lyh
changeset 14598:0d37fda09415
Allow monotonically decending inputs to bicubic ().
bicubic.m: Permit the original inputs to be monotonically decending.
Slight improvments to coding style. Add test. (Bug # 36351).
author | Ben Abbott <bpabbott@mac.com> |
---|---|
date | Thu, 03 May 2012 18:34:39 -0400 |
parents | 11a9d448fdc3 |
children | de72463862c4 |
files | scripts/general/bicubic.m |
diffstat | 1 files changed, 44 insertions(+), 10 deletions(-) [+] |
line wrap: on
line diff
--- a/scripts/general/bicubic.m +++ b/scripts/general/bicubic.m @@ -50,9 +50,9 @@ if (isa (x, "single") || isa (y, "single") || isa (z, "single") || isa (xi, "single") || isa (yi, "single")) - myeps = eps("single"); + myeps = eps ("single"); else - myeps = eps; + myeps = eps (); endif if (nargin <= 2) @@ -65,8 +65,8 @@ z = x; x = []; [rz, cz] = size (z); - s = linspace (1, cz, (cz-1)*pow2(n)+1); - t = linspace (1, rz, (rz-1)*pow2(n)+1); + s = linspace (1, cz, (cz-1) * pow2 (n) + 1); + t = linspace (1, rz, (rz-1) * pow2 (n) + 1); elseif (nargin == 3) if (! isvector (x) || ! isvector (y)) error ("bicubic: XI and YI must be vector"); @@ -88,6 +88,23 @@ error ("bicubic: X, Y and Z must be equal size matrices of same size"); endif + if (all (diff (x) < 0)) + flipx = true; + x = fliplr (x); + elseif (all (diff (x) > 0)) + flipx = false; + else + error ("bicubic:nonmonotonic", "bicubic: X values must be monotonic") + endif + if (all (diff (y) < 0)) + flipy = true; + y = flipud (y); + elseif (all (diff (y) > 0)) + flipy = false; + else + error ("bicubic:nonmonotonic", "bicubic: Y values must be monotonic") + endif + ## Mark values outside the lookup table. xfirst_ind = find (xi < x(1)); xlast_ind = find (xi > x(cz)); @@ -99,9 +116,8 @@ yi(yfirst_ind) = y(1); yi(ylast_ind) = y(rz); - x = reshape (x, 1, cz); - x(cz) *= 1 + sign (x(cz))*myeps; + x(cz) *= 1 + sign (x(cz)) * myeps; if (x(cz) == 0) x(cz) = myeps; endif; @@ -111,7 +127,7 @@ xidx = o(find (i > cz)); y = reshape (y, rz, 1); - y(rz) *= 1 + sign (y(rz))*myeps; + y(rz) *= 1 + sign (y(rz)) * myeps; if (y(rz) == 0) y(rz) = myeps; endif; @@ -121,8 +137,15 @@ yidx = o([find(i > rz)]); ## Set s and t used follow codes. - s = xidx + ((xi .- x(xidx))./(x(xidx+1) .- x(xidx))); - t = yidx + ((yi - y(yidx))./(y(yidx+1) - y(yidx))); + s = xidx + ((xi .- x(xidx)) ./ (x(xidx+1) .- x(xidx))); + t = yidx + ((yi - y(yidx)) ./ (y(yidx+1) - y(yidx))); + + if (flipx) + s = fliplr (s); + endif + if (flipy) + t = flipud (t); + endif else print_usage (); endif @@ -198,7 +221,6 @@ endfunction - %!demo %! clf; %! colormap ("default"); @@ -211,3 +233,15 @@ %! [x,y] = meshgrid (x,y); %! hold on; plot3 (x(:),y(:),A(:),"b*"); hold off; +%!test +%! x = linspace (1, -1, 10); +%! [xx, yy] = meshgrid (x); +%! z = cos (6 * xx) + sin (6 * yy); +%! x = linspace (1, -1, 30); +%! [xx2, yy2] = meshgrid (x); +%! z1 = interp2 (xx, yy, z, xx2, yy2, "cubic"); +%! z2 = interp2 (fliplr(xx), flipud(yy), fliplr(flipud(z)), +%! fliplr(xx2), flipud(yy2), "cubic"); +%! z2 = fliplr (flipud (z2)); +%! assert (z1, z2, 100 * eps ()) +