Hi every one. I have a moving point on the axes. How my point can move in this direction( look at picture)? Cause now it`s just moving from x 0 to x 3.6, idk what to do next

[Jan]

Post the current code if you need suggestions for modifying it.

[Daniel Ryzhuk]

@Jan %plot(x,y)

%plot(0,0, '.','MarkerSize',10)

axes();

title('Ilmsens office')

xlabel('x-coordinate [m]')

ylabel('y-coordinate [m]')

xlim([0,3.6])

ylim([0,6.15])

view([90 -90])

hold on

% Sensor 1

%Tx1 = plot(0.2600, 0.2800,'rv','MarkerSize',6); %Tx1

%Rx1 = plot(0.1919, 0.3559,'rv','MarkerSize',6); %Rx1

%Rx2 = plot(0.3280, 0.2040,'rv','MarkerSize',6); %Rx2

% Sensor 2

%Tx2 = plot(3.3200, 0.2900,'gv','MarkerSize',6);

%Rx3 = plot(3.2450, 0.2206,'gv','MarkerSize',6);

%Rx4 = plot(3.3947, 0.3594,'gv','MarkerSize',6);

% Sensor 3

%Tx3 = plot(3.3000, 5.8600,'bv','MarkerSize',6);

%Rx5 = plot(3.3809, 5.7979,'bv','MarkerSize',6);

%Rx6 = plot(3.2190, 5.9220,'bv','MarkerSize',6);

%stepX

pmax = 1; % total no of dots

x = 0 ; %initialise the coordinates of each dots

y = 0 ;

dt = 0.25;

lifespan = 15; % life span : the total no of steps each dot has to move

for i =1:lifespan

if i == 1

for k = 1 : pmax

grid on;

hold on;

plot(x, y, 'ro-');

axis([0 3.6 0 6.15])

pause(0.4);

hold off;

end

else

h = findobj(gca,'Type', 'line');

for k = 1 : pmax

prevX = get(h(k),'XData');

%prevY = get(h(k),'YData');

set(h(k),'XData',prevX+dt)

%set(h(k),'YData',prevY+dt)

pause(0.4);

end

end

end

%stepY

Answer 1

[John D'Errico]

You will want to do this in a parametric form. That is, think about how x moves, as a function of TIME. Don't think about y as a function of x, since it is not such a thing anyway. There is no functional relationship there.

But if you plot x(t), it would be constant for a while, then it would increase LINEARLY. then be constant for another time. You could do that using interp1. For example:

t = linspace(0,10,1000);
tbreaks = 0:1:10;
xbreaks = [0 0 1 1 2 2 3 3 4 4 5];
% think about how you could generate this sequence for longer spans. Is not
% hard. For example, could you use repmat?
x_t = interp1(tbreaks,xbreaks,t,'linear');
plot(t,x_t)

Now, you will do something similar for y_t. Even though the plot versus t might not look as you wish, when you then form the plot for x_t versus y_t, it will be correct.

Just think carefully about what the set of y values should be. As long as you were careful about how you generated ybreaks, the two curves will be exactly as you want.

ybreaks = [0 1 1 0 0 1 1 0 0 1 1];
y_t = interp1(tbreaks,ybreaks,t,'linear');
plot(x_t,y_t,'.')

This should get you started. The function animatedline might get you the rest of the way.

[Daniel Ryzhuk]

Thank u very much for your help :)