Analog Clock with Nelson

[Nelson-numerical-software]

An basic example of Plot animation to design analog clock with Nelson:

f = figure();
hold on;
x=0;
y=0;
r=10;
theta = 0:pi/60:2*pi;
xc = r * cos(theta);
yc = r * sin(theta);
h = plot(xc, yc, 'b', 'LineWidth', 4);
axis equal
axis off
r = 9;
i = 1;
ax = gca();
ax.FontWeight = 'bold';

for theta = pi/6: pi/6: 2*pi
  y1 = r * cos(theta);
  x1 = r * sin(theta);
  plot([x1/9*8 x1/9*7],[y1/9*8 y1/9*7],'Color',[0 0 1])
  text(x1/9*9.5,y1/9*9.5,num2str(i),'Color',[0 0 1]);
  i=i+1;
end

for theta=pi/30 : pi/30 : 2*pi
  y1 = 10 * cos(theta);
  x1 = 10 * sin(theta);
  plot([x1/9*8 x1/9*7], [y1/9*8 y1/9*7], 'Color', [0 0 0])
end
reverseStr = '';
while(1)
  tic
  c = clock;
  c = c(1,4:6);
  minute =c(1,2);
  sec=c(1,3);
  if (c(1,1)>12)
    hr = c(1,1)-12;
  else
    hr = c(1,1);
  end
  min1 = ceil(minute/12);
  theta = (hr*pi)/6 + (min1*pi)/30;
  hold on;
  y1 = 3 * cos(theta); 
  Yhr = [0 y1];
  x1 = 3 * sin(theta);
  Xhr = [0 x1];
  hrhnd = plot(Xhr,Yhr);
  hrhnd.LineWidth = 6;
  hold on;
  theta1 = (minute*pi)/30;
  y2 = 4.5 * cos(theta1);
  Ymin = [0 y2];
  x2 = 4.5 * sin(theta1);
  Xmin = [0 x2];
  minhnd = plot(Xmin,Ymin);
  minhnd.LineWidth = 3;
  theta2 = (sec*pi)/30;
  y3 = 5 * cos(theta2);
  Ysec = [0 y3];
  x3 = 5 * sin(theta2);
  Xsec = [0 x3];
  sechnd  =  plot(Xsec,Ysec);
  sechnd.LineWidth = 2;
  z=toc;
  pause(1-z);
  children = ax.Children;
  children(children == sechnd) = [];
  children(children == minhnd) = [];
  children(children == hrhnd) = [];
  ax.Children = children;
  
  msg = sprintf('%2d:%2d:%2d', hr, minute, sec);
  fprintf([reverseStr, msg]);
  reverseStr = repmat(sprintf('\b'), 1, length(msg));
end