lplot(varargin)

function hh = lplot(varargin)

%LPLOT PLOT function that cycles through different line styles.
%   LPLOT(X,Y) plots Y versus X just like the PLOT command but cycles
%   through 12 different line styles instead of colors (4 line styles x 3
%   line widths).  The axes LineStyleOrder is set to '-|:|--|-.' and axes
%   ColorOrder is set to [0 0 0].  Multiple data sets, accepted by PLOT,
%   are allowed. e.g. LPLOT(X1, Y1, X2, Y2, ...) or LPLOT(X, [Y1, Y2, ...])
%
%   H = LPLOT(...) returns a vector of line handles.
%
%   Example:
%     x = (0:0.1:10)';
%
%     y1  = 1.2 * sin(x);
%     y2  = 0.7 * cos(0.3 * x);
%     y3  = 2   * sin(0.7 * x);
%     y4  = y1  + y2;
%     y5  = y1  + y3;
%     y6  = y2  + y3;
%     y7  = y1  - y2;
%     y8  = y1  - y3;
%     y9  = y3  - y2;
%     y10 = y1 .* y2;
%     y11 = y1 .* y3;
%     y12 = y2 .* y3;
%
%     h = lplot(x, [y1, y2, y3, y4, y5, y6, y7, y8, y9, y10, y11, y12]);
%     legend(h, ...
%       'y1','y2','y3','y4','y5','y6','y7','y8','y9','y10','y11','y12', ...
%       'Location', 'EastOutside');
%
%   See also PLOT, LINE.

%   VERSIONS:
%     v1.0 - first version
%     v1.1 - added more linestyles
%     v1.2 - added option to specify LineStyleOrder
%     v1.3 - remove optional LineStyleOrder option. reset properties
%            afterwards.
%     v1.4 - allow all numeric input arguments accepted by PLOT. more line
%            types (12).
%
% Copyright 2005-2010 The MathWorks, Inc.

if nargin < 1
  error('Not enough inputs arguments');
end

% This is the prevent passing Param-Value pairs. If using Param-Value
% pairs, use PLOT instead.
if any(cellfun('isclass', varargin, 'char'))
  error('All input arguments must be numeric matrices');
end

% prepare axes
axh = newplot;
nextplot = get(axh, 'NextPlot');

% get current LineStyleOrder and ColorOrder
LSCO = get(axh, {'LineStyleOrder', 'ColorOrder'});

% set LineStyleOrder and ColorOrder
set(axh, 'LineStyleOrder', '-|:|--|-.', ...
  'ColorOrder', [0 0 0]);

% if the NextPlot property is 'replace', then PLOT will reset the
% LineStyleOrder and the ColorOrder properties.
% so change it to 'replacechildren'
if strcmpi(nextplot, 'replace')
  set(axh, 'NextPlot', 'replacechildren');
end

% plot
h = plot(varargin{:});

% if there are more than 4 lines, change the thickness of the lines
if length(h) > 4
  lw = get(h(1), 'linewidth');
  set(h([5:12:end,  6:12:end,  7:12:end,  8:12:end]), 'linewidth', lw * 4);
  set(h([9:12:end, 10:12:end, 11:12:end, 12:12:end]), 'linewidth', lw * 8);
end

% restore NextPlot, LineStyleOrder, and ColorOrder
set(axh, {'NextPlot','LineStyleOrder', 'ColorOrder'}, {nextplot,LSCO{:}});

if nargout == 1
  hh = h;
end