Matlab_learning_2（Pie‘s source code饼状图源码）

一、源代码

function hh = pie(varargin)%PIE    Pie chart.%   PIE(X) draws a pie plot of the data in the vector X.  The values in X%   are normalized via X/SUM(X) to determine the area of each slice of pie.%   If SUM(X) <= 1.0, the values in X directly specify the area of the pie%   slices.  Only a partial pie will be drawn if SUM(X) < 1.%%   PIE(X,EXPLODE) is used to specify slices that should be pulled out from%   the pie.  The vector EXPLODE must be the same size as X. The slices%   where EXPLODE is non-zero will be pulled out.%%   PIE(...,LABELS) is used to label each pie slice with cell array LABELS.%   LABELS must be the same size as X and can only contain strings.%%   PIE(AX,...) plots into AX instead of GCA.%%   H = PIE(...) returns a vector containing patch and text handles.%%   Example%      pie([2 4 3 5],{'North','South','East','West'})%%   See also PIE3.%   Clay M. Thompson 3-3-94%   Copyright 1984-2005 The MathWorks, Inc.%   $Revision: 1.16.4.11 $  $Date: 2011/07/25 03:49:31 $% Parse possible Axes input[cax,args,nargs] = axescheck(varargin{:});error(nargchk(1,3,nargs,'struct'));x = args{1}(:); % Make sure it is a vectorargs = args(2:end);nonpositive = (x <= 0);if all(nonpositive)    error(message('MATLAB:pie:NoPositiveData'));endif any(nonpositive)  warning(message('MATLAB:pie:NonPositiveData'));  x(nonpositive) = [];endxsum = sum(x);if xsum > 1+sqrt(eps), x = x/xsum; end% Look for labelsif nargs>1 && iscell(args{end})  txtlabels = args{end};  if any(nonpositive)    txtlabels(nonpositive) = [];  end  args(end) = [];else  for i=1:length(x)    if x(i)<.01,      txtlabels{i} = '< 1%';    else      txtlabels{i} = sprintf('%d%%',round(x(i)*100));    end  endend% Look for explodeif isempty(args),   explode = zeros(size(x)); else   explode = args{1};   if any(nonpositive)     explode(nonpositive) = [];   endendexplode = explode(:); % Make sure it is a vectorif length(txtlabels)~=0 && length(x)~=length(txtlabels),  error(message('MATLAB:pie:StringLengthMismatch'));endif length(x) ~= length(explode),  error(message('MATLAB:pie:ExploreLengthMismatch'));endcax = newplot(cax);next = lower(get(cax,'NextPlot'));hold_state = ishold(cax);theta0 = pi/2;maxpts = 100;inside = 0;h = [];for i=1:length(x)  n = max(1,ceil(maxpts*x(i)));  r = [0;ones(n+1,1);0];  theta = theta0 + [0;x(i)*(0:n)'/n;0]*2*pi;  if inside,    [xtext,ytext] = pol2cart(theta0 + x(i)*pi,.5);  else    [xtext,ytext] = pol2cart(theta0 + x(i)*pi,1.2);  end  [xx,yy] = pol2cart(theta,r);  if explode(i),    [xexplode,yexplode] = pol2cart(theta0 + x(i)*pi,.1);    xtext = xtext + xexplode;    ytext = ytext + yexplode;    xx = xx + xexplode;    yy = yy + yexplode;  end  theta0 = max(theta);  h = [h,patch('XData',xx,'YData',yy,'CData',i*ones(size(xx)), ...               'FaceColor','Flat','parent',cax), ...         text(xtext,ytext,txtlabels{i},...              'HorizontalAlignment','center','parent',cax)];endif ~hold_state,   view(cax,2); set(cax,'NextPlot',next);   axis(cax,'equal','off',[-1.2 1.2 -1.2 1.2])endif nargout>0, hh = h; end% Register handles with m-code generatorif ~isempty(h)  mcoderegister('Handles',h,'Target',h(1),'Name','pie');end

二、效果图