% phasecolor - display of using color to represent phase angle
%
% Usage: 
%         [pc,rgbColor,rgbCircle]=phasecolor(rangeSelect,angle)
%
% matching 360 deg of angle to 0-1 and use it as Hue. 
% Both Saturation and Values are full (1).
%
% Arguments:
%         rangeSelect - 0, range = [0,360]  (default)
%                       1, range = [-180,180]
%         angle       - optional, be pointed out in the graph
% Output:
%         pc    - 4 x 360 matrix
%               - 1st row is the angle (1-360)
%               - 2nd-4th rows are the R,G,B color value(0-255)
%         rgbColor  - image matrix of the lower output
%         rgbCircle - image matrix of the circle output
%
% Author: 
% Tzu Yen Wong
% wongt AT csse DOT uwa DOT edu DOT au
% Department of Computer Science & Software Engineering
% The University of Western Australia
%
% Oct 2003
% June 2004 change email address to fight SPAM!!!

%1234567890123456789012345678901234567890123456789012345678901234567890123456789

function [pc,rgbColor,rgbCircle]=phasecolor(rangeSelect,angle)


    hsvColor=ones(40,360,3);
    hsvColor(:,:,1)=ones(1,40)'*[1/360:1/360:1];
    hsvColor(:,:,2:3)=1;
    
    titleText1 = 'Representation of phase angle using hsv color';
    titleText2 = 'Range of angle in degree =';
    
    if nargin >0,
        if rangeSelect == 1,        % if range is [-180,180]
            hsvColor2(:,181:360,:)=hsvColor(:,1:180,:);
            hsvColor2(:,1:180,:)  =hsvColor(:,181:360,:);
            hsvColor = hsvColor2;
            
            titleText = sprintf('%s\n%s %s',titleText1,titleText2,'[-180,180]');
        else
            rangeSelect = 0; 
            titleText = sprintf('%s\n%s %s',titleText1,titleText2,'[0,360]');
        end
    else
        rangeSelect = 0;
        titleText = sprintf('%s\n%s %s',titleText1,titleText2,'[0,360]');
    end
    
    if nargin >1;
        while angle<=0;
            angle = angle+360;
        end
        
        while angle>360;
            angle = angle-360;
        end
        
        hsvColor(25:40,:,3)=0;
        hsvColor(25:40,angle,3)=1;
        hsvColor(25:40,angle,2)=0;
        
        if rangeSelect == 1,        % if range is [-180,180]
            if angle >180,
                angle = angle-360;
            end
        end

        titleText = sprintf('%s \nAngle of interest in degree = %d',...
            titleText,angle);

    end
    % To make the column index equal angle in degree
    % RGB color range: 0-255
    rgbColor=uint8(hsv2rgb(hsvColor)*255);
    
    figNo = figure; clf; 
    
    subplot(2,1,2);
    subplot('position',[.01 .05 .98 .35])
    imshow([rgbColor rgbColor])                  % show 0-720 deg
    xlabel('angle(degree)');
    pixval on
    axis on
      
    
    pc(:,2:4) = rgbColor(1,:,:);
    pc=double(pc);  
    pc(1:360,1) = [1:360.0]';

    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    
    r = 150;
    hsvCircle = ones(2*r+1,2*r+1,3);
    xCoord = ones(2*r+1,1)*[1:2*r+1] - (r+1);    
    yCoord = flipud([1:2*r+1]'*ones(1,2*r+1)- (r+1));
    circle = xCoord.^2+yCoord.^2 < (r*.8)^2;
    circle(:,:,2)=circle;
    circle(:,:,3)=circle(:,:,1);
    
    % get angle in degree
    warning off MATLAB:divideByZero;
    hsvCircle(:,:,1)=atan(yCoord./xCoord)*180/pi; 
    % make angle into range [0,360] instead of [-180,180]
    hsvCircle(:,1:r,1) = hsvCircle(:,1:r,1) + 180;      % 2nd, 3rd Quadrant
    hsvCircle(r+1:end,r+1:end,1) = hsvCircle(r+1:end,r+1:end,1) + 360; % 4th Quadrant
    
    % make angle into range [0,1] for hsv color
    hsvCircle(:,:,1) = hsvCircle(:,:,1)/360;
    
    if rangeSelect == 1,        % if range is [-180,180]
        hsvCircle(:,:,1) = flipud(fliplr(hsvCircle(:,:,1)));
        hsvCircle(:,:,2) = flipud(fliplr(hsvCircle(:,:,2)));
        hsvCircle(:,:,3) = flipud(fliplr(hsvCircle(:,:,3)));
    end
        
    rgbCircle=hsv2rgb(hsvCircle);
    rgbCircle=rgbCircle.*circle;
    rgbCircle=uint8(rgbCircle*255);
    
    figure(figNo),
    subplot(2,1,1)
    subplot('position',[.25 .4 .5 .5])
    
    imshow(rgbCircle)
    title(titleText);
    hold on,
    if nargin >1,
        angleRad=angle*pi/180;                      % sin and cosine work in Rad
        x1=r*cos(angleRad);    y1=r*sin(angleRad);
        x2=r*.8*cos(angleRad); y2=r*.8*sin(angleRad);
        % shift origin to (r+1), axis ij, flip y-coord
        X = [x1,x2]+(r+1);     Y = (r+1)-[y1,y2];
        line(X,Y)
        axis ij
    end
    truesize    
    hold off
    warning on