Closing the figure window causes a new figure window to open - matlab

Question

This is a analog clock. It runs perfectly. But once I close the clock, another figure opens up, and only the clock hands show. This makes it difficult to stop the program. How can I stop the program?
x=0;y=0;r=10;
hold on;
theta = 0:pi/60:2*pi;
xc = r * cos(theta);
yc = r * sin(theta);
h = plot(xc,yc,'r','linewidth',4);
axis off
r=9; i=1;
set(gca,'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
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;
f=figure(1); hold on;
y1 = 3 * cos(theta); Yhr = [0 y1];
x1 = 3 * sin(theta); Xhr = [0 x1];
hrhnd=plot(Xhr,Yhr);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);
theta2 = (sec*pi)/30;
y3 = 5 * cos(theta2); Ysec = [0 y3];
x3 = 5 * sin(theta2); Xsec = [0 x3];
sechnd=plot(Xsec,Ysec);
z=toc;
pause(1-z);
delete(sechnd);
delete(minhnd);
delete(hrhnd);
end

Answer 1

The simplest way to stop the script when you close the window is to have the script test inside its loop if the window still exists.
We start the script by creating a figure window and recording its handle:
fig = figure;
Next, in the loop, we check to see if the window still exists using ishandle:
while(ishandle(fig))
...
end
The full program:
x=0;y=0;r=10;
fig = figure; %!!! NEW LINE
hold on;
theta = 0:pi/60:2*pi;
xc = r * cos(theta);
yc = r * sin(theta);
h = plot(xc,yc,'r','linewidth',4);
axis off
r=9; i=1;
set(gca,'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
while(ishandle(fig)) %!!! UPDATED LINE
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;
f=figure(1); hold on;
y1 = 3 * cos(theta); Yhr = [0 y1];
x1 = 3 * sin(theta); Xhr = [0 x1];
hrhnd=plot(Xhr,Yhr);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);
theta2 = (sec*pi)/30;
y3 = 5 * cos(theta2); Ysec = [0 y3];
x3 = 5 * sin(theta2); Xsec = [0 x3];
sechnd=plot(Xsec,Ysec);
z=toc;
pause(1-z);
delete(sechnd);
delete(minhnd);
delete(hrhnd);
end
You could improve your program by not deleting and re-drawing the hands, but updating their position. You'd do hrhnd=plot(Xhr,Yhr); before the loop, to draw the hand in its initial position, and then set(hrhnd,'XData',Xhr,'YData', Yhr) to update its position.
You could also do axis equal after drawing the clock face, to ensure it is round.
Note that you only need to give hold on once at the top, it is not needed after every plot command.