function flowers(a,b,r,mode,N,gifname)

%万花尺程序

%input -a 大圆半径 -b 小圆半径 -r 画笔距小圆圆心的距离

% -mode ：非0 表示小圆沿大圆内侧转动

% 0 表示小圆沿大圆外侧转动

% a = 4;b = 1.2;mode =1;r = b;%10花尺

% a = 4;b = 2;mode =1;r = 3;%2花尺

% a = 4;b = 1;mode =1;r = b;%4花尺

% a = 4;b = 1.5;mode =1;r = b;%8花尺

% a = 4;b = 0.75;mode =1;r = b;%16花尺

% a = 4;b = 8/3;mode =1;r = b;%6花尺

% a = 4;b = 8/9;mode =1;r = b;%9花尺

% a = 4;b = 4/3;mode =1;r = b/2;%3花尺

% a = 4;b = 1;mode =1;r = b/2;%4花尺

% a = 4;b = 2;mode =1;r = b;%2花尺

if nargin < 3,r = b;end

if nargin < 4 || mode,mode = -1;else mode = 1;end

if nargin < 5,N = 10;end

if nargin < 6,gifname = 'flowers.gif';end

[k,m] = cylnumber(a,b,N);

t = 0:pi/200:2*k*pi;

tt = 0:pi/200:2*pi;

x1 = a+mode*b;

xx = a*cos(tt); yy = a*sin(tt);

plot(xx,yy);

xm = a+abs(r+mode*b);

axis equal off

title([num2str(m),'花尺'])

%设置颜色、标记、标记尺寸、擦除模式

h = line('Color','k','Marker','*',...

'MarkerSize',1,'EraseMode','xor');

h2 = line('Color','k','Marker','.',...

'MarkerSize',8,'EraseMode','xor');

h1 = line('Color','r','Marker','.',...

'MarkerSize',20,'EraseMode','xor');

n = length(t);

if mode == -1,nk = n:-1:1;else nk = 1:n;end

for k = 1:n

x = x1*cos(t(k))+r*cos(x1/b*t(nk(k)));

y = x1*sin(t(k))+r*sin(x1/b*t(nk(k)));

x2 = x1*cos(t); y2 = x1*sin(t);

x3 = x2(k)+b*cos(tt); y3 = y2(k)+b*sin(tt);

hold on

set(h,'xdata',x3,'ydata',y3); %画图、画线设置

plot(x,y,'r.');

set(h2,'xdata',[x x2(k)],'ydata',[y y2(k)]);

set(h1,'xdata',[x x],'ydata',[y y]);

axis([-xm,xm,-xm,xm]);

try

f = getframe;

imind = frame2im(f); %将单帧图像转化为RGB图像

[imind,cm] = rgb2ind(imind,256);

if k ~= 1

imwrite(imind,cm,gifname,'gif','WriteMode','append','DelayTime',.05)

else

imwrite(imind,cm,gifname,'gif','Loopcount',inf,'DelayTime',.05)

end

end

pause(0.00001)

end

function [k,m] = cylnumber(a,b,N)

k = 1;

m = a/b;

while rem(m,1) && k < N

k = k + 1;

m = k*a/b;

end