Global Index (short | long) | Local contents | Local Index (short | long)
[cout,H,CS] = contourf(varargin)
CONTOURF Filled contour plot.
CONTOURF(...) is the same as CONTOUR(...) except that the contours
are filled. Areas of the data at or above a given level are filled.
Areas below a level are either left blank or are filled by a lower
level. NaN's in the data leave holes in the filled contour plot.
C = CONTOURF(...) returns contour matrix C as described in CONTOURC
and used by CLABEL.
[C,H,CF] = CONTOURF(...) also returns a column vector H of handles
to PATCH objects and the contour matrix CF for the filled areas.
The UserData property of each object contains the height value for each
contour.
Example:
z=peaks; contourf(z), hold on, shading flat
[c,h]=contour(z,'k-'); clabel(c,h), colorbar
See also CONTOUR, CONTOUR3, CLABEL, COLORBAR.
| This function is called by | |
|---|---|
function [cout,H,CS] = contourf(varargin)
% Author: R. Pawlowicz (IOS) rich@ios.bc.ca 12/14/94
% Copyright (c) 1984-98 by The MathWorks, Inc.
% $Revision: 1.21 $ $Date: 1997/11/21 23:46:10 $
error(nargchk(1,5,nargin));
% Check for empty arguments.
for i = 1:nargin
if isempty(varargin{i})
error ('Invalid Argument - Input matrix is empty');
end
end
% Trim off the last arg if it's a string (line_spec).
nin = nargin;
if isstr(varargin{end})
[lin,col,mark,msg] = colstyle(varargin{end});
if ~isempty(msg), error(msg); end
nin = nin - 1;
else
lin = '';
col = '';
end
if (nin == 4),
[x,y,z,nv] = deal(varargin{1:4});
if (size(y,1)==1), y=y'; end;
if (size(x,2)==1), x=x'; end;
[mz,nz] = size(z);
elseif (nin == 3),
[x,y,z] = deal(varargin{1:3});
nv = [];
if (size(y,1)==1), y=y'; end;
if (size(x,2)==1), x=x'; end;
[mz,nz] = size(z);
elseif (nin == 2),
[z,nv] = deal(varargin{1:2});
[mz,nz] = size(z);
x = 1:nz;
y = (1:mz)';
elseif (nin == 1),
z = varargin{1};
[mz,nz] = size(z);
x = 1:nz;
y = (1:mz)';
nv = [];
end
if nin <= 2,
[mc,nc] = size(varargin{1});
lims = [1 nc 1 mc];
else
lims = [min(varargin{1}(:)),max(varargin{1}(:)), ...
min(varargin{2}(:)),max(varargin{2}(:))];
end
i = find(isfinite(z));
minz = min(z(i));
maxz = max(z(i));
% Generate default contour levels if they aren't specified
if length(nv) <= 1
if isempty(nv)
CS=contourc([minz maxz ; minz maxz]);
else
CS=contourc([minz maxz ; minz maxz],nv);
end
% Find the levels
ii = 1;
nv = minz; % Include minz so that the contours are totally filled
while (ii < size(CS,2)),
nv=[nv CS(1,ii)];
ii = ii + CS(2,ii) + 1;
end
end
% Don't fill contours below the lowest level specified in nv.
% To fill all contours, specify a value of nv lower than the
% minimum of the surface.
draw_min=0;
if any(nv <= minz),
draw_min=1;
end
% Get the unique levels
nv = sort([minz nv(:)']);
zi = [1, find(diff(nv))+1];
nv = nv(zi);
% Surround the matrix by a very low region to get closed contours, and
% replace any NaN with low numbers as well.
zz=[ repmat(NaN,1,nz+2) ; repmat(NaN,mz,1) z repmat(NaN,mz,1) ; repmat(NaN,1,nz+2)];
kk=find(isnan(zz(:)));
zz(kk)=minz-1e4*(maxz-minz)+zeros(size(kk));
xx = [2*x(:,1)-x(:,2), x, 2*x(:,nz)-x(:,nz-1)];
yy = [2*y(1,:)-y(2,:); y; 2*y(mz,:)-y(mz-1,:)];
if (min(size(yy))==1),
[CS,msg]=contours(xx,yy,zz,nv);
else
[CS,msg]=contours(xx([ 1 1:mz mz],:),yy(:,[1 1:nz nz]),zz,nv);
end;
if ~isempty(msg), error(msg); end
% Find the indices of the curves in the c matrix, and get the
% area of closed curves in order to draw patches correctly.
ii = 1;
ncurves = 0;
I = [];
Area=[];
while (ii < size(CS,2)),
nl=CS(2,ii);
ncurves = ncurves + 1;
I(ncurves) = ii;
xp=CS(1,ii+(1:nl)); % First patch
yp=CS(2,ii+(1:nl));
Area(ncurves)=sum( diff(xp).*(yp(1:nl-1)+yp(2:nl))/2 );
ii = ii + nl + 1;
end
newplot;
if ~ishold,
view(2);
% set(gca,'xlim',lims(1:2),'ylim',lims(3:4))
setm(gcm,'maplonlimit',lims(1:2),'maplatlimit',lims(3:4))
end
% Plot patches in order of decreasing size. This makes sure that
% all the leves get drawn, not matter if we are going up a hill or
% down into a hole. When going down we shift levels though, you can
% tell whether we are going up or down by checking the sign of the
% area (since curves are oriented so that the high side is always
% the same side). Lowest curve is largest and encloses higher data
% always.
H=[];
[FA,IA]=sort(-abs(Area));
if ~isstr(get(gca,'color')),
bg = get(gca,'color');
else
bg = get(gcf,'color');
end
if isempty(col)
edgec = get(gcf,'defaultsurfaceedgecolor');
else
edgec = col;
end
if isempty(lin)
edgestyle = get(gcf,'defaultpatchlinestyle');
else
edgestyle = lin;
end
% Define colormap for plotting conventions
cmap = colormap;
if size(cmap, 1) ~= 1 & length(nv) ~= 1;
c1 = size(cmap, 1)
c1inc = 0:(1 / (c1-1)):1
c2 = length(nv)
c2inc = 0:(1 / (c2-2)):1
cmap = interp2(1:3, c1inc, cmap, 1:3, c2inc')
end
for jj=IA,
nl=CS(2,I(jj));
lev=CS(1,I(jj));
if (lev ~=minz | draw_min ),
xp=CS(1,I(jj)+(1:nl));
yp=CS(2,I(jj)+(1:nl));
if (sign(Area(jj)) ~=sign(Area(IA(1))) ),
kk=find(nv==lev);
if (kk>1+sum(nv<=minz)*(~draw_min)),
lev=nv(kk-1);
else
lev=NaN; % missing data section
end;
end;
cind = find(nv == lev)
if (isfinite(lev))
H=[H;patchm(yp,xp,lev,'facecolor',cmap(cind,:),'edgecolor',edgec,'linestyle',edgestyle)];
else
H=[H;patchm(yp,xp,lev,'facecolor',bg,'edgecolor',edgec,'linestyle',edgestyle)];
end;
end;
end;
numPatches = length(H);
if numPatches>1
for i=1:numPatches
set(H(i), 'faceoffsetfactor', 0, 'faceoffsetbias', (1e-3)+(numPatches-i)/(numPatches-1)/30);
end
end
if nargout>0,
% Return contour matrix for unfilled contours
% cout=contours(x,y,z,nv);
cout = CS;
end