%PLOTM Plot mapping values, contours or surface
%
% H = PLOTM(W,S,N)
%
% INPUT
% W Trained mapping
% S Plot strings, or scalar selecting type of plot
% 1: density plot;
% 2: contour plot (default);
% 3: 3D surface plot;
% 4: 3D surface plot above 2D contour plot;
% 5; 3D mesh plot;
% 6: 3D mesh plot above 2D contour plot)
% N Contour level(s) to plot
% (default: 10 contours between minimum and maximum)
%
% OUTPUT
% H Array of graphics handles
%
% DESCRIPTION
% This routine, similar to PLOTC, plots contours (not just decision
% boundaries) of the mapping W on predefined axis, typically generated by
% SCATTERD. Plotstrings may be set in S. The vector N selects the contour.
%
% If N = 'perc' 10 contour levels are drawn such that each level has an
% equal area in the plot.
%
% EXAMPLES
% See PREX_DENSITY
%
% SEE ALSO (<a href="http://37steps.com/prtools">PRTools Guide</a>)
% MAPPINGS, SCATTERD, PLOTC
% Copyright: R.P.W. Duin, r.p.w.duin@37steps.com
% Faculty EWI, Delft University of Technology
% P.O. Box 5031, 2600 GA Delft, The Netherlands
% $Id: plotm.m,v 1.4 2009/09/25 13:15:17 duin Exp $
function handle = plotm(w,arg2,n,cnd)
ismapping(w); % Assert that W is a mapping.
w = w*setbatch; % Avoid memory prolems with large gridsizes
% Get the parameters, the plotstrings and the number of contours.
if (nargin < 4)
cnd = 1;
end;
[k,c] = size(w);
if (nargin < 3)
n = [];
end
plottype = 2; s = [];
if (nargin >= 2)
if (~isstr(arg2) & ~isempty(arg2))
plottype = arg2;
else
s = arg2;
end
end
if plottype == 2 & size(w,1) == 1
plottype = 1;
end
if (nargin < 2) | (isempty(s))
col = 'brmk';
s = [col' repmat('-',4,1)];
s = char(s,[col' repmat('--',4,1)]);
s = char(s,[col' repmat('-.',4,1)]);
s = char(s,[col' repmat(':',4,1)]);
s = char(s,s,s,s);
end
% When one contour should be plotted, two entries have to be given in
% the contour plot (Matlab bug/feature).
%if (~isempty(n)) & (length(n) == 1), n = [n n]; end
% Setup the mesh-grid, use the axis of the currently active figure.
% Note: this will be a 0-1 grid in case of no given scatterplot.
hold on; V = axis;
gs = gridsize; dx = (V(2)-V(1))/gs; dy = (V(4)-V(3))/gs;
if (plottype == 1)
m = (gs+1); X = (V(1):dx:V(2))';
D = double([X,zeros(m,k-1)]*w);
D = real(D);
else
m = (gs+1)*(gs+1); [X Y] = meshgrid(V(1):dx:V(2),V(3):dy:V(4));
D = double([X(:),Y(:),zeros(m,k-2)]*w);
D = real(D);
end;
if (~cnd)
% where is this used?? For what? (RD)
D = sum(D,2);
end;
% HH will contain all handles to graphics created in this routine.
hh = [];
% Plot the densities in case of 1D output.
if (plottype == 1)
for j = 1:size(D,2)
if (size(s,1) > 1), ss = s(j,:); else ss = s; end
% Plot the densities and add the handles to HH.
h = plot([V(1):dx:V(2)],D(:,j),deblank(ss));
hh = [hh; h];
end
axis ([V(1) V(2) 0 1.2*max(max(D))]);
ylabel('Density')
end
% Plot the contours in case of 2D output.
if (plottype == 2) | (plottype == 4) | (plottype == 6)
% Define the contour-heights if they are not given.
if (isempty(n))
n = 10;
dmax = max(D(:)); dmin = min(D(:)); dd = (dmax-dmin)/(n+1);
n = [dmin+dd:dd:dmax-dd];
elseif ischar(n) && strcmp(n,'perc')
n = prctile(D,5:10:95);
end;
if length(n) == 1, n = [n n]; end
% Plot the contours for each of the classes.
for j = 1:size(D,2)
if (size(s,1) > 1), ss = s(j,:); else, ss = s; end
Z = reshape(D(:,j),gs+1,gs+1);
% Plot the contours and add the handles to HH.
[cc, h] = contour([V(1):dx:V(2)],[V(3):dy:V(4)],Z,n,deblank(ss));
hh = [hh; h];
end
view(2);
end
% Plot the surface in case of 3D output.
if (plottype == 3) | (plottype == 4) | (plottype == 5) | (plottype == 6)
% Scale the outputs to cover the whole colour range.
%E = D - min(D(:));
%E = 255*E/max(E(:))+1;
E = D; % Scaling appears disputable (RD)
if (c>1)
Z = reshape(sum(E,2),gs+1,gs+1);
else
Z = reshape(E(:,1),gs+1,gs+1);
end
if (plottype == 4) | (plottype == 6)
Z = Z + max(max(Z));
end;
% Plot the surface, set up lighting and add the handles to HH.
h = surf([V(1):dx:V(2)],[V(3):dy:V(4)],Z);
if (plottype == 3) | (plottype == 4)
colormap jet;
shading interp;
set(h,'FaceColor','interp','EdgeColor','none','FaceLighting','none ');
else
colormap white;
shading faceted;
end
view(-37.5,20);
camlight left; % Necessary to solve camlight bug?
camlight headlight;
camlight right;
hh = [hh; h];
end
hold off; if (nargout > 0), handle = hh; end
return