diceplot(varargin)

function diceplot(varargin)
%DICEPLOT plots a die for dice games
%    DICEPLOT(NUMBER) plots the dice with dots for the given dice NUMBER,
%     values which range from 1 to 6. Unknown is represented by either -1 or '?'
%    DICEPLOT(NUMBER, HANDLE) sets the the current axis to that specified
%     by HANDLE
%    DICEPLOT(NUMBER, HANDLE, COLOR) sets the the current axis to the
%     specified COLOR, a thre element vector


% make constant array of colors for the axis
colorsofdice = [1.0 0.8 0.8; 0.8 1.0 0.8; 0.8 0.8 1.0; 1.0 1.0 0.8; 1.0 0.8 1.0; 0.8 1.0 1.0];

if nargin
    number = varargin{1};
    if number == '?'
        number = -1 ;  %unkown case
    end
    if ischar(number)
        number = str2num(number);
    end
    if ~sum( (number == [-1,1:6]) ) % check for integer match, -1 means '?'
        error('Matlab:diceplot', 'Dice number is not valid');
    end
else
    number = -1; %default to unknown if no inputs
end
if nargin >= 2
    axes(varargin{2}); % set current axis
end
cla;

str = '\cdot';                  % symbol to plot
col = 'k';                      % color of symbol
ax = axis;                      % get current scaling of axis
fsize = 2.5/diff(ax(3:4));      % font size
offy = 0.15*fsize*diff(ax(3:4));% calculate y-offset

%  | 1   5 |
%  | 2 4 6 |        % die dots positions
%  | 3   7 |
xlocs = [0.2 0.2 0.2 0.5 0.8 0.8 0.8];
ylocs = [0.8 0.5 0.2 0.5 0.8 0.5 0.2];

switch number % select dot positions for given die number
    case 1
        dots = [4];
    case 2
        dots = [3 5];
    case 3
        dots = [3 4 5];
    case 4
        dots = [1 3 5 7];
    case 5
        dots = [1 3 4 5 7];
    case 6
        dots = [1 2 3 5 6 7];
    otherwise
        str = '?';
        dots = [4];
        fsize = fsize/2.5;
        offy = 0;
end
xlocs = xlocs(dots);
ylocs = ylocs(dots);

h = text(xlocs, ylocs+offy, str);   % display dots
set(h, 'HitTest', 'off');           % make unselectable

set(h,'fontunits','norm','fontsize',fsize,'HorizontalAlignment','center','VerticalAlignment','middle')

if nargin >= 3 % enter color routines
    if varargin{3} == 1 % we want to set color
        if number > 0
            set(varargin{2}, 'Color', colorsofdice(number,:) ); % set current axis
        end
    else
        set(varargin{2}, 'Color', [1 1 1]); % set axis to white    
    end
end